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Do you think the P34 caliper would feel even worse with the stock master cylinder?
I've got the Magura radial master and P34 front caliper. It doesn't feel particularly special but it isn't bad. I'd like a little more lever progression and more power of the 4 piston caliper. Never felt I needed it with what I have though.
 

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I don’t have a ton of lever movement with the stock master cylinder and 4-piston caliper. The lever only moves about a quarter of an inch, before the pads hit the rotor and you feel that firmness. I suppose more lever throw would be ideal, with power ramping up the more you pull. With that said, I have never found it difficult to modulate the braking power with this setup. It is very predictable and manageable. I trail brake all the time with ease.

I do strongly believe that decades of mountain biking experience, where you are riding fast on loose surface terrain, with powerful brakes and a very small amount of rubber on the ground, has helped my braking abilities immeasurably. Road biking has helped too, where you have a contact patch smaller than a dime and are in some cases descending mountains at 60+mph. I’ve noticed that former BMX riders also develop supreme rear brake skills, which are very useful. You learn real well where that fine line is between bleeding off speed, or locking up and crashing. I will say that you don’t have as much feel using your foot for rear braking as you do with your hand, like on a bicycle.
 
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Discussion Starter · #144 ·
Crossed the 5K mile mark on my 2019 Grom, and only on the 2nd engine!

The Kitaco Neo hit the 900 mile mark, so I was overdue for valve adjustment.

It has been running great!

The cylinder head nuts were retorqued to 24 Nm. They were pretty loose and out of spec from the initial assembly. About 1/4 turn require for each to hit 24Nm again.

This was my 3rd oil and filter change. Did the first dino oil at 50 miles, the 2nd synthetic oil at 400 and now at 900 miles full synthetic oil and filter change. My plan is doing them every 1K miles from now on.

Valves were very close to spec. A tiny bit of tightening to tolerance.

The Cam chain was a bit loose. I am using the DHM manual cam tensioner. Required about 1/4 turn on the adjuster to get the chain slack back to about about 1/4 inch. Wish there was a more precise way to set the chain tension, but so far so good. Cam chain guide wheels look pristine.

All and all very satisfied with this build!
 

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Sounds like an awesome bike, Pard. You have built it up right. I really like that Neo kit.
 
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Discussion Starter · #146 · (Edited)
Been playing with the target AFR setting in the aRacer app.

As recommended in several threads on this forum, running the BBK engines at AFRs closer to 12.2 will provide best power.

Confirmed that with my setting today.

Running 12.7 from 50% throttle throughout the RPM range down to 12.2 at WOT and the bike pulls harder. Higher top speed.

Engine temps are slightly higher as well, despite a richer setting, due to the increased power being created. Still within reasonable limits. 200F oil temp and 350 CHT were the highest I saw over the course of an hour hard riding. Much time spent at WOT.

Only getting 80 miles to a full tank with this setup. Power means fuel burn!

From a thread on this forum :


AFR Values & Characteristics in Four Stroke Engines
6.0 AFR - Rich Burn Limit (engine fully warm)
9.0 AFR - Black Smoke / Low Power
11.5 AFR - Best Rich Torque at Wide Open Throttle
12.2 AFR - Safe Best Power at Wide Open Throttle
13.3 AFR - Lean Best Torque
14.6 AFR - Stoichiometric AFR (Stoich)
15.5 AFR - Lean Cruise
16.5 AFR - Usual Best Economy
18.0 AFR - Carbureted Lean Burn Limit
22.0+ AFR - EEC / EFI Lean Burn Limit
 

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Only getting 80 miles to a full tank with this setup. Power means fuel burn!
I don't get much better, and I have way less power. It is the high rpm at WOT that kills mine.
 
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Thanks for posting the fuel burn. I’ve always been curious what the numbers were for BBK bikes. I never keep up with mileage on my bike or anything else I own.
 
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When I could cruise the 181 4 valve I was approaching 100 mpg. It was impressive to see those numbers. 12.5:1 compression ratio, ceramic wheel bearings, and non o-ring chain keeping efficiency way up.
 

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When I could cruise the 181 4 valve I was approaching 100 mpg. It was impressive to see those numbers. 12.5:1 compression ratio, ceramic wheel bearings, and non o-ring chain keeping efficiency way up.
I’m surprised it had that good of fuel efficiency. That is impressive. Is the Monkey tank the same size as the Grom’s? I think mine is 1.45 gallons on my SF.

Ceramic bearings are used in the bicycle world on high end builds. They make a difference. Especially when your body is the engine.

I’m a firm believer in non o-ring chains on these bikes. I don’t want the additional drag of o-rings on bikes with so little power. Especially when running 125cc.
 
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I’m surprised it had that good of fuel efficiency. That is impressive. Is the Monkey tank the same size as the Grom’s? I think mine is 1.45 gallons on my SF.

Ceramic bearings are used in the bicycle world on high end builds. They make a difference. Especially when your body is the engine.

I’m a firm believer in non o-ring chains on these bikes. I don’t want the additional drag of o-rings on bikes with so little power. Especially when running 125cc.
1.5 gallon tank.

If I go Takegawa again I'll get the dry clutch for more power/efficiency.
 

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If I go Takegawa again I'll get the dry clutch for more power/efficiency.
I was hanging out at a weekly concert recently with hundreds and hundreds of motorcycles, when a Ducati Panigale V4R arrived. 234hp! Wow, what a sexy bike. It had that unique, dry clutch sound as it went by. Pretty neat. I went over and talked to the guy. He was super nice and mentioned that he owned a Grom too.
 

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Hey Pard, when you were running your 186 BBK, didn’t you add a ported, larger valve head to it at some point? I thought I remember a post where you added one and said you couldn’t tell a difference in performance.

If this is correct, what head did you install and what were the specs? Also, what happened to the head when the rod broke? Did it get damaged?
 

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Discussion Starter · #154 ·
Hey Pard, when you were running your 186 BBK, didn’t you add a ported, larger valve head to it at some point? I thought I remember a post where you added one and said you couldn’t tell a difference in performance.

If this is correct, what head did you install and what were the specs? Also, what happened to the head when the rod broke? Did it get damaged?
I used this:

Finbro Ported Upgraded SUPER AWESOME Head 3.0 for 125cc bore Includes: 27 mm / 23 mm Valves


When my engine failed, the crankshaft failed at the piston rod pin and the piston separated totally destroying the piston and valves in the head, and marring up the head itself.
 

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Discussion Starter · #155 ·
Just noticed this caution in the HR details on the Finbro head:

"The DCR CAM & TB CAM are NOT RECOMMENDED to be used in this Head."

I was running a TB cam with the DHM kit don't you know. I do not recall that warning being listed at the the time of purchase. Maybe that caused my failure? But after 3K miles?
 

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Discussion Starter · #156 ·
I actually inquired from DHM if there was a head recommended:

David,

Great kit! Installed and running well. Love it!

I was wondering what a cylinder head you offer to make this setup as good as it can be.

Thanks,

---------

Great to hear it’s running well! You can run one of the Finbro heads from Hard Racing.

Regards,
David


------

:(:oops::unsure:
 

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Hey Pard, when you were running your 186 BBK, didn’t you add a ported, larger valve head to it at some point? I thought I remember a post where you added one and said you couldn’t tell a difference in performance.

If this is correct, what head did you install and what were the specs? Also, what happened to the head when the rod broke? Did it get damaged?
Just as a counterpoint, I was running the Takegawa 181 2 valve with stock head and then did a ported head and matched intake pipe and noticed a big difference in power all through the rpm range.

Then the cam sprocket cam off and switched to Kitaco type 2 cam and it made ok power but I don't think it jived well with the setup.
 

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Just noticed this caution in the HR details on the Finbro head:

"The DCR CAM & TB CAM are NOT RECOMMENDED to be used in this Head."

I was running a TB cam with the DHM kit don't you know. I do not recall that warning being listed at the the time of purchase. Maybe that caused my failure? But after 3K miles?
Was the quality of that head any good? As you know, Finbro gets mixed reviews on this forum, but what was your experience with the head? Did it need a lot of clean-up? Just curious.

I doubt that had anything to do with your failure. I don’t know why Hard Racing has that on their website. I bet tons of people are running that combo.
Just as a counterpoint, I was running the Takegawa 181 2 valve with stock head and then did a ported head and matched intake pipe and noticed a big difference in power all through the rpm range.

Then the cam sprocket cam off and switched to Kitaco type 2 cam and it made ok power but I don't think it jived well with the setup.
Do you still have that head? Was it sized for a 34mm throttle body?

Interesting. I think you touch on something that I’ve noticed from reading everyone’s experiences. Different combinations of parts, even when somewhat similar, can definitely yield different results. I’ve read more than one review where someone said a ported head did nothing, but I’ve read others where the person said the difference was huge. I think sometimes if one ingredient is off or doesn’t work well with something else, the outcome can be lackluster. We are having an issue kind of like this with my buddy’s bike.

I want to do a few more things to my setup, which runs great, but I just want to be sure I hit a home run and actually see some gains. Not necessarily anything huge, but at least worth it. I’m ok with several small gains, because when added together, they make a difference.
 

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Discussion Starter · #159 ·
Was the quality of that head any good? As you know, Finbro gets mixed reviews on this forum, but what was your experience with the head? Did it need a lot of clean-up? Just curious.

I doubt that had anything to do with your failure. I don’t know why Hard Racing has that on their website. I bet tons of people are running that combo.
The head was immaculate. No issues with it at all.
 

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