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Discussion Starter · #1 · (Edited)
Hey all!

Recently installed the TB Cam and DHM high comp piston. Only other installed mods would be intake and exhaust as well as a reflashed ECU for everything. I'm still breaking it in but was able to get GPS confirmed speeds of 72 so far (ran both ways on a highway, same day using Waze app. Everybody tells me 100 mi break in, then ride the bike normally. I've got about 20 excruciating miles left.

I had a buddy buy a used Grom with similar mods, but had an aRacer full kit installed. He said he was running it up to redline (he thinks he was a little above 70, maybe approaching 75) and his piston seized after about 15 minutes. Besides having similar mods I think the RPM was set at 10,500, whereas I was conservative and have mine only at 9750 to avoid valve issues. Has anyone had any similar issues with these mods?

I'm thinking that the aRacer might not have been properly tuned and/or he may have had detonation, but it's hard to imagine a failure after only running redline for 15 minutes. I added my mods for light freeway running, but will keep the speeds way down if it'll only lead to tragic results (unless, maybe needing coolers or other mods are a possibility.) I've had one or two other people tell me, not to worry about it and that as long as I use at least 91 octane, I should be fine.

So far everything's running beautifully and have had only one stall after a cold start. It happened the day after I installed the new piston and ECU and only had about 20 miles into the break in period. My only complaint is that my dam pipes are (probably) too loud XD.

Thoughts, opinions, suggestions appreciated.

Thanks!!
 

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I have never done a “break in” on any internal combustion engine I’ve owned. Ever. Cars, trucks, boats, lawnmowers, etc. I subscribe to the “break it in like you plan to use it everyday” school of thought. If I feel like running it hard, I run it hard. I have never noticed any ill effects from this. Ever. I don’t feel like I abuse anything. It all looks new and runs perfectly. I watched a YouTube video where they took two different Yamaha R3 engines, broke one in easy, gave one hell. They could find no measurable differences. Maybe not the most conclusive test, but it completely aligns with my experiences.

Most people feel that 10,000rpms is safe on stock valve springs. It sounds like your buddy’s AFR was not set correctly, or maybe he was running additional timing, or was not using high enough octane fuel. I’d say if the AFR was way off, 15 minutes would be sufficient. Go watch Chillis’ video in the Monkey Builds section. An oil cooler wouldn’t hurt. Higher compression means more heat. Too much heat can kill an engine, but plenty of people run a high compression 125cc piston with no oil cooler.
 

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Discussion Starter · #3 ·
I appreciate the reply.

Maybe I should be a little more specific. Should I worry about cooling if I'm running 60-70 mph? I understand that cooling is ALWAYS going to help engine life, and Groms/Monkeys aren't about freeway speeds, but it'd be nice to know that I could do it, if needed.

Chili has actually helped me out figuring out my build. Shame he blew his motor recently. He had an awesome setup.
Problem is, there's lots of conflicting info. Some people say they are running a similar setup with no oil cooler and have had no issues - at least initially. And when they have problems it's due to other failed components that do not seem to be related to running high speeds (for example, I read where a few riders broke sprockets, chains, clutches) There have others with the same setup and have motor failures. Of the failures, it's about the same story. Daily ridden, sustained high speeds in the high 60's low 70's and then a random failure. The problem is, of the failures, there's typically no follow up for the cause. Bad piston? Heat? Usually once the motor goes, the rider moves onto a bigger bike "that's more suited for what they need", or they replace the motor with a big bore. So, nothing conclusive.

The answer is typically "get a sensor and monitor your temps", but what's considered "normal operating temps" seems to span from low 200's to 250 deg F. That's quite a spread. Unknown overland was getting 220-230 without a cooler and then in the 210's when he added the cooler (tho I think he has a fuel controller and not a reflashed ECU), so it almost seems that the cooler isn't doing much. Then again, it DID look like he was doing his initial testing during the winter, so it's hard to say.

Sorry for the wall of text. Just thinking out loud. I guess my real question is should I get it sooner than later, or just abandon going that fast, until I do put some sort of external cooling on the engine? I was going to change out the clutch cover anyway to eliminate having to clean out the screen and spinner. I was hoping to go 5 speed next =(
 

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I’m a big fan of having supporting mods when you start adding more horsepower. My bike seemed to hold slightly more oil once I added the Kitaco clutch cover. That is a good thing. My Kitaco 3-row super oil cooler also increases oil capacity. I’m running the Takegawa super oil pump, Takegawa cam chain tensioner, Kitaco tensioner button, Kitaco billet clutch lifter plate, Kitaco 60% stiffer clutch springs, Takegawa 4th crankshaft bearing. In theory, all of these items should contribute to greater reliability.

The weak link is the connecting rod and crankshaft and there is nothing you can do about that with the stock bore. Both of them have failed on Groms, including stock Groms. The high compression piston puts more stress on both the crank and rod, while simultaneously producing more heat. I think to some degree, the chances of a failure are increased. It’s just the nature of adding more compression. It’s the risk you take when you start modding something that engineers designed to operate within certain, limited parameters. We are asking a lot out of these little engines. I understand your concerns.

My friend is running the DHM high compression piston with no oil cooler, but he is only riding the Grom in cold weather. This time of year he is off adventure biking for weeks at a time. I don’t believe Ninelives17 is running an oil cooler. He lives in southern Alabama. It gets super hot there. He is running the DHM high compression piston with a ported head, 34mm throttle body, DCR cam, aRacer, Dinger Built intake, Hindle exhaust, etc., so his bike is producing a good amount of power. He puts a lot of miles on his bike. It’s still going.

You are getting more airflow to an air cooled engine at 60-70mph, so that part is good, but the engine is producing more heat. Oil temps often go down, but cylinder head temps rise at those speeds. Some of the failures could be caused by poorly set ring gaps or improper tuning. On the Internet, you never really know for sure if the person who installed the parts or did the tuning, did a good job or not. I’ve seen plenty of shoddy work and some things that were downright janky.

Always take your time, triple check yourself, aim for excellence and precision, when working on your bike. If you do quality work, have supporting mods, and good tuning, then that hopefully removes a few variables from the equation, that you don’t need to worry about.

I believe Unknown Overland is running the aRacer Mini 5 ECU. An oil cooler isn’t going to lower temperatures by 50 degrees. Maybe something like 10-15 degrees, but I think it’s worth it. Mine, knock on wood, has never leaked even the tiniest drop of oil. They work great.
 

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Discussion Starter · #5 ·
I’m a big fan of having supporting mods when you start adding more horsepower. My bike seemed to hold slightly more oil once I added the Kitaco clutch cover. That is a good thing. My Kitaco 3-row super oil cooler also increases oil capacity. I’m running the Takegawa super oil pump, Takegawa cam chain tensioner, Kitaco tensioner button, Kitaco billet clutch lifter plate, Kitaco 60% stiffer clutch springs, Takegawa 4th crankshaft bearing. In theory, all of these items should contribute to greater reliability.

The weak link is the connecting rod and crankshaft and there is nothing you can do about that with the stock bore. Both of them have failed on Groms, including stock Groms. The high compression piston puts more stress on both the crank and rod, while simultaneously producing more heat. I think to some degree, the chances of a failure are increased. It’s just the nature of adding more compression. It’s the risk you take when you start modding something that engineers designed to operate within certain, limited parameters. We are asking a lot out of these little engines. I understand your concerns.

My friend is running the DHM high compression piston with no oil cooler, but he is only riding the Grom in cold weather. This time of year he is off adventure biking for weeks at a time. I don’t believe Ninelives17 is running an oil cooler. He lives in southern Alabama. It gets super hot there. He is running the DHM high compression piston with a ported head, 34mm throttle body, DCR cam, aRacer, Dinger Built intake, Hindle exhaust, etc., so his bike is producing a good amount of power. He puts a lot of miles on his bike. It’s still going.

You are getting more airflow to an air cooled engine at 60-70mph, so that part is good, but the engine is producing more heat. Oil temps often go down, but cylinder head temps rise at those speeds. Some of the failures could be caused by poorly set ring gaps or improper tuning. On the Internet, you never really know for sure if the person who installed the parts or did the tuning, did a good job or not. I’ve seen plenty of shoddy work and some things that were downright janky.

Always take your time, triple check yourself, aim for excellence and precision, when working on your bike. If you do quality work, have supporting mods, and good tuning, then that hopefully removes a few variables from the equation, that you don’t need to worry about.

I believe Unknown Overland is running the aRacer Mini 5 ECU. An oil cooler isn’t going to lower temperatures by 50 degrees. Maybe something like 10-15 degrees, but I think it’s worth it. Mine, knock on wood, has never leaked even the tiniest drop of oil. They work great.
Thanks very much for the detailed reply! I think for now I'm going to keep my speeds down until I get the oil cooler and clutch cover installed. I didnt want to trust myself for the piston install as I knew the ring gapping would be tricky. I did everything else and - like you said - triple checked everything to make sure I hadn't missed anything. I was lucky enough to find a mechanic to do the piston work who happens to race on weekends and knows his way around Groms and Monkeys. He's installed many a HC piston as well as other tuning parts in them. I'm part of a Facebook mini moto group and they trust him with their bikes, regardless of engine capacity.

I was actually super confident about the mods until I ran into that guy that just bought that used Grom and killed his motor. That just filled my head with doubts, and that led down the rabbit hole of what else I need to put into the bike. I've put so much work into the bike already, the last thing I really want to do is ruin it by neglecting to install what I need to keep it reliable.

You mentioned a cam chain tensioner, crankshaft bearing and a few other mods that I thought were meant more for big bore kits. Do you think they're needed for my build?

Lastly, I'm not really wringing every little drop out of my Monkey. I don't stunt, do stop light races, or even ride hard. The most I'd do performance-wise is ride at 65-70 if I have to get on a highway. So far, I've only been past 60 just to check what speeds I'd get and those were extremely brief stints - like maybe 1/2 mile to a mile at most.

Once again, thanks very much for your insights. I think I know which direction I want to take for my build.

90579
 

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I do not have an oil cooler yet, but will be installing one soon. I have had no issues cruising at 60-65 mph which is over 9000 rpm with my gearing, while sitting straight up for hours. We did 440 miles in one day, most of it was done at 60+ mph. No problems.
 

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Thanks very much for the detailed reply! I think for now I'm going to keep my speeds down until I get the oil cooler and clutch cover installed. I didnt want to trust myself for the piston install as I knew the ring gapping would be tricky. I did everything else and - like you said - triple checked everything to make sure I hadn't missed anything. I was lucky enough to find a mechanic to do the piston work who happens to race on weekends and knows his way around Groms and Monkeys. He's installed many a HC piston as well as other tuning parts in them. I'm part of a Facebook mini moto group and they trust him with their bikes, regardless of engine capacity.

I was actually super confident about the mods until I ran into that guy that just bought that used Grom and killed his motor. That just filled my head with doubts, and that led down the rabbit hole of what else I need to put into the bike. I've put so much work into the bike already, the last thing I really want to do is ruin it by neglecting to install what I need to keep it reliable.

You mentioned a cam chain tensioner, crankshaft bearing and a few other mods that I thought were meant more for big bore kits. Do you think they're needed for my build?

Lastly, I'm not really wringing every little drop out of my Monkey. I don't stunt, do stop light races, or even ride hard. The most I'd do performance-wise is ride at 65-70 if I have to get on a highway. So far, I've only been past 60 just to check what speeds I'd get and those were extremely brief stints - like maybe 1/2 mile to a mile at most.

Once again, thanks very much for your insights. I think I know which direction I want to take for my build.

View attachment 90579
That is a good looking bike. Who knows what that used Grom had been put through or if it was built right. I wouldn’t use that one instance as the definitive proof that all high compression builds are going to fail.

Well, the stock cam chain tensioner works of course, but it does dig into the rubber tensioner button where it makes contact. It is a rather thin piece of metal. A poor design. Over time the tensioner button begins to fall apart. Eventually the tensioner arm can get pushed up into the gears. The Takegawa cam chain tensioner has a very wide foot where it contacts the button. This spreads the load out preventing it from ever digging into the rubber. It is a nice CNC machined piece of aluminum.

You can take it a step further and replace the tensioner button with one made of a harder material. According to Chillis, these are not all created equally. Some of them don’t let enough oil slip past them causing an over pressure situation. I would stick with the Takegawa or Kitaco versions. Another option would be a manual cam chain tensioner, eliminating the button altogether.

I installed the 4th crankshaft bearing in hopes that it might help prevent the crankshaft from breaking. I’ve seen several Grom SF cranks snapped off at the flywheel. Some people have said they don’t think the extra bearing helps that particular situation. There is no way to know. It isn’t completely clear as to why the cranks break to begin with. It seems hit or miss. It provides support for the end of the crank that the heavy flywheel is on, so I felt like it was a good idea to install it, while I was replacing the cam chain tensioner.

If you install a new clutch cover and an oil cooler, then that is a perfect time to install a higher flow oil pump. You are asking more of the oil pump when adding an oil cooler. It is also the perfect time to replace the clutch lifter plate and install 60% stiffer clutch springs, if you haven’t already. The stock springs are a joke. The 60% stiffer springs feel like what should have come on the bike to begin with.
 

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Discussion Starter · #8 ·
Thanks again for the input guys! I'll look to add the cooler in a few months. I've been lucky and the temps out here in Missouri have been milder than usual. Mid 80's low 90's so far and if I ride in the mornings or at dusk the temps are just about perfect for a worry-free ride with no particular destination in mind. My average speeds are below 40 mph per Waze, and I'd only do 60+ on a highway - which would be convenient, but not necessary - so I dont think I'll need to worry about installing the cooler anytime soon. It'd be nice just to have that peace of mind. For now, I guess I'll just slow down and let the engine cool a bit if I need to travel at 60+ for more than a mile.

I think I'm also going to install the stiffer clutch springs and lifter plate while I'm down there as that clutch feel is pretty numb. I end up trying to feather it quite a bit when moving from a stop, just because the engagement point is... well... about the only time I know I'm on it is when the bike starts moving.

I've heard about the tensioner button. Hopefully, someone will release an aftermarket solution that is a definite fix. I'm not sure about the offerings yet as no one's chimed in about any advantages or issues they've had about them.

I was really hoping to be able to forego the cooler and just do the 5 speed, but something tells me that I should do the cooler first, look into that tensioner issue (if you can call it that), and then finish my bike mods with the 5 speed.

In the far flung future, I'm thinking about buying a used engine and trans from a CB125R and installing that. Liquid cooling, 6 speed, and about 14.5 HP. Top speeds on the stock CB are 75, Pretty sure the Monkey/Groms can get a few MPH more... and that would be pretty reliable, so long as nothing else is done to it.
 

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Regarding the tensioner button and cam chain tensioner arm, I think these are the definite fix. They work great. Tensioner wheels don’t last forever, but that is a wear item, that you replace periodically. Usually, it is thousands of miles.
 

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Thanks again for the input guys! I'll look to add the cooler in a few months. I've been lucky and the temps out here in Missouri have been milder than usual. Mid 80's low 90's so far and if I ride in the mornings or at dusk the temps are just about perfect for a worry-free ride with no particular destination in mind. My average speeds are below 40 mph per Waze, and I'd only do 60+ on a highway - which would be convenient, but not necessary - so I dont think I'll need to worry about installing the cooler anytime soon. It'd be nice just to have that peace of mind. For now, I guess I'll just slow down and let the engine cool a bit if I need to travel at 60+ for more than a mile.

I think I'm also going to install the stiffer clutch springs and lifter plate while I'm down there as that clutch feel is pretty numb. I end up trying to feather it quite a bit when moving from a stop, just because the engagement point is... well... about the only time I know I'm on it is when the bike starts moving.

I've heard about the tensioner button. Hopefully, someone will release an aftermarket solution that is a definite fix. I'm not sure about the offerings yet as no one's chimed in about any advantages or issues they've had about them.

I was really hoping to be able to forego the cooler and just do the 5 speed, but something tells me that I should do the cooler first, look into that tensioner issue (if you can call it that), and then finish my bike mods with the 5 speed.

In the far flung future, I'm thinking about buying a used engine and trans from a CB125R and installing that. Liquid cooling, 6 speed, and about 14.5 HP. Top speeds on the stock CB are 75, Pretty sure the Monkey/Groms can get a few MPH more... and that would be pretty reliable, so long as nothing else is done to it.
Is the CB125R a laydown engine?

I'm looking for swaps for my blown engine.
 

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Discussion Starter · #12 · (Edited)
Alas, it is not a lay down motor. Your Monkey was actually the catalyst for looking to see what swaps might be possible.

The configuration is similar to the CB250/350r, but it is much narrower. It also has a 6 speed.

So the positives:
- I'm pretty sure it weighs about the same as a big bore kit, even with the radiator/fan/reservoir.
- Installing it will likely be similar to a 250/300 swap, without making it feel like a different bike since the weight is going to be around the same as a bike bore kit.
- Reliability (if it's installed correctly)

The negatives
- Modding the frame for fitment
- The other drawback is that there's not much in the way of hop up parts - at least none that I've seen that can bump it past 16 HP.
- Used, they look to be around $1000-2000 in the UK, used without any type of ECU, wiring harnesses, and misc, so I think the swap is doable, but not without a LOT of effort.

Might almost be worth it to by one of those Takagawa 181 prebuilt bolt ons with the slipper clutch, 5 speed, and misc parts. Supposedly those put out 22 HP. (Found here) https://www.motorkit.com/en/head-pa...alve-5-speed-engine-and-racingwet-clutch.html But, geez, you can get another Monkey for the same price - and that's not even with an ECU! And then there's still the worry of cooling it.
 

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Alas, it is not a lay down motor. Your Monkey was actually the catalyst for looking to see what swaps might be possible.

The configuration is similar to the CB250/350r, but it is much narrower. It also has a 6 speed.

So the positives:
  • I'm pretty sure it weighs about the same as a big bore kit, even with the radiator/fan/reservoir.
  • Installing it will likely be similar to a 250/300 swap, without making it feel like a different bike since the weight is going to be around the same as a bike bore kit.
  • Reliability (if it's installed correctly)

The negatives
- Modding the frame for fitment
- The other drawback is that there's not much in the way of hop up parts - at least none that I've seen that can bump it past 16 HP.
- Used, they look to be around $1000-2000 in the UK, used without any type of ECU, wiring harnesses, and misc, so I think the swap is doable, but not without a LOT of effort.

Might almost be worth it to by one of those Takagawa 181 prebuilt bolt ons with the slipper clutch, 5 speed, and misc parts. Supposedly those put out 22 HP. (Found here) https://www.motorkit.com/en/head-pa...alve-5-speed-engine-and-racingwet-clutch.html But, geez, you can get another Monkey for the same price - and that's not even with an ECU! And then there's still the worry of cooling it.
I'm fairly confident that my bike would have been a reliable monster if the fueling was right.

Based on what I could find the timing was good.

Once up in the rpm range it ran hot. This happened from the very beginning following ARacer tuning instructions. The bike was lean midrange on up and I felt it in the vibration.

Once I messed with fuel base it became much smoother but it had been run hot more than a few times already so damage was done. Never got to feel the full power of the setup and that is the real shame.

I'm most likely going the prebuilt Takegawa route since I need an entire engine. Maybe swap the head for a 5 axis ported version.

Going to be a bit due to work constraints.
 

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Discussion Starter · #14 ·
I'm fairly confident that my bike would have been a reliable monster if the fueling was right.

Based on what I could find the timing was good.

Once up in the rpm range it ran hot. This happened from the very beginning following ARacer tuning instructions. The bike was lean midrange on up and I felt it in the vibration.

Once I messed with fuel base it became much smoother but it had been run hot more than a few times already so damage was done. Never got to feel the full power of the setup and that is the real shame.

I'm most likely going the prebuilt Takegawa route since I need an entire engine. Maybe swap the head for a 5 axis ported version.

Going to be a bit due to work constraints.

It was a pretty impressive set up to be sure! I'm pretty sure you could've easily had one of the fastest "gorillas' out there had it not been for the heat issues. Please update your (re)build so we can live vicariously through you when you get the new motor - whatever that'll be!!

XD
 

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$5885 USD for that Takegawa engine from MotorKit, plus shipping on top of that, so easily over $6000. Then I would still need an aRacer Mini 5 ECU, AF1 module, and harness for about $730. With a motor like that, a Hindle exhaust would make sense for my Grom, so another $400. $50 for sprockets. Maybe a larger oil cooler, cylinder head temp gauge, crankcase ventilation, too. So $7500 total?

I would definitely order it from Webike for $3546. It would probably be $5000 after shipping and all the other items are added in. Hmmm.

Using existing parts I already own, combined with a Kitaco Neo kit I could probably build my engine up for $3000, with a 5-speed. That is including all the aRacer stuff and Hindle exhaust. I think Kenny at GromFatherz claims to have gotten around 24hp out of a Kitaco Neo build, so 22hp should be achievable. Yeah, I could see me maybe spending $3000 someday, but I doubt I would spend $5000.

I can imagine the Takegawa being worth it to some people depending on their wealth. The labor to assemble the engine has been completed for you, so that has value too.
 

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$5885 USD for that Takegawa engine from MotorKit, plus shipping on top of that, so easily over $6000. Then I would still need an aRacer Mini 5 ECU, AF1 module, and harness for about $730. With a motor like that, a Hindle exhaust would make sense for my Grom, so another $400. $50 for sprockets. Maybe a larger oil cooler, cylinder head temp gauge, crankcase ventilation, too. So $7500 total?

I would definitely order it from Webike for $3546. It would probably be $5000 after shipping and all the other items are added in. Hmmm.

Using existing parts I already own, combined with a Kitaco Neo kit I could probably build my engine up for $3000, with a 5-speed. That is including all the aRacer stuff and Hindle exhaust. I think Kenny at GromFatherz claims to have gotten around 24hp out of a Kitaco Neo build, so 22hp should be achievable. Yeah, I could see me maybe spending $3000 someday, but I doubt I would spend $5000.

I can imagine the Takegawa being worth it to some people depending on their wealth. The labor to assemble the engine has been completed for you, so that has value too.
Webike all day for the engine. $4k shipped.

Motorkit is way overpriced.

Webike is doing their summer sale right now. Would if I could but I can't at the moment.
 

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lol…Webike has been blowing up my email for almost a month now. If the Takegawa 5-speed transmission was in stock, I would have considered buying one.

At the current exchange rate, it looks like the complete Takegawa engine would be about 3727.47 shipped with FedEx shipping. That is the wet clutch model. I agree with you Chillis, this is probably one of the most attractive options available, if you don’t want to salvage your engine. It would look much better than a 300 engine swap and maintain a low center of gravity. After installation, It would all come down to tuning and cooling from there.
 
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Discussion Starter · #18 ·
It's the cooling part that I'm worried about. That's why I'm playing around with the idea of having the liquid cooled 125. It's not as bulky as the 250/300 (it's actually only slightly heftier than the stock 125), but it is not a lying flat configuration, like the stock engine. It would need a cradle and then the harness(es) for the electronics, but I think reliability-wise, it's better than a big bore. The 2021's are putting out 15-16ish HP, so it's a pretty good option, in my opinion, so long as - 1) you can source the engine and associated parts (from europe/asia), 2) you can showhorn it onto the frame 3) you can fit the radiator w/cooler reservoir etc. I don't have any faith that any of the big bores have any reliability without reinforcing just about everything on it. THEN you have to figure catch cans and proper oil cooling.
 

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It's the cooling part that I'm worried about. That's why I'm playing around with the idea of having the liquid cooled 125. It's not as bulky as the 250/300 (it's actually only slightly heftier than the stock 125), but it is not a lying flat configuration, like the stock engine. It would need a cradle and then the harness(es) for the electronics, but I think reliability-wise, it's better than a big bore. The 2021's are putting out 15-16ish HP, so it's a pretty good option, in my opinion, so long as - 1) you can source the engine and associated parts (from europe/asia), 2) you can showhorn it onto the frame 3) you can fit the radiator w/cooler reservoir etc. I don't have any faith that any of the big bores have any reliability without reinforcing just about everything on it. THEN you have to figure catch cans and proper oil cooling.
Adding all of the extra parts to make bbk's work is a nuisance.

I'm not opposed to a swap for that reason.
 

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Discussion Starter · #20 ·
Adding all of the extra parts to make bbk's work is a nuisance.

I'm not opposed to a swap for that reason.
I hear ya. Every single person I know of that's put one in and didn't tune it conservatively (or had a cooling failure) has blown their motor. The mechanic I go to that does the work I'm not willing to risk messing up on has done dozens of upgrades, from modest upgrades like mine, to full blown 200+cc big bores. He said that that ALL of the big bores eventually need tear downs (and part replacements/reinforcements) to keep them running reliably. He (and his garage-mates) race on the weekends and when they talk shop, he finds that Grom owners are always fiddling with their BBKs. And when they aren't fiddling, they're repairing/replacing. It just goes hand in hand with BBKs. I LOVE to tinker, but there's a point where you just want to ride.

Since the new Groms are coming out, the prices of OG and SF Groms are falling. I see myself nabbing one with engine issues for a grand or two and then seeing what I can stuff into it. OR - just get a stock motor and hop it up like my monkey and put that RC213 body kit on it. They have a fully carbon version that looks sharp.

I've seen Monkeys with the 250/300 swap, and I can say I'm not a fan - but it's not so much the fabrication of the cradle, or the relocation of various misc stuff... it's the whole girth of the motor sticking out of the sides. Makes it look like a pregnant scooter. I think if you take a look at the 2021 CB125R, you can see that it's not big at all - even the radiator looks tiny. I had mistakenly thought they put it in the CRF125F, but no... that's also a Grom motor.. BUT, it's not laying down either. SO... maybe it's possible to lay the water cooled engine down and fit the 4/5 speed to it. I'm almost to the point of signing up on one of their forums to see if I can get detailed pics. I think the Aussie's are getting them this year, so maybe someone from the land downunder could also help investigate?
 
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