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My Monkey really struggles when I ask it go up hill from a dead stop.

There's a hill near my house that I encounter on a regular basis.
If I'm approaching it in 2nd gear and am able to turn onto it with no cars in front of me, the Monkey takes it like a champ.
But, if I have to slow down to 1st or stop before climbing it, the Monkey really objects.

I find myself wanting to do that Fred Flintstone duck walk thing to help it out, but that would just make me unstable.
I only weigh 125lbs, so it's not my weight.
Anyone else encounter this? Advice?
 

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My Monkey really struggles when I ask it go up hill from a dead stop.

There's a hill near my house that I encounter on a regular basis.
If I'm approaching it in 2nd gear and am able to turn onto it with no cars in front of me, the Monkey takes it like a champ.
But, if I have to slow down to 1st or stop before climbing it, the Monkey really objects.

I find myself wanting to do that Fred Flintstone duck walk thing to help it out, but that would just make me unstable.
I only weigh 125lbs, so it's not my weight.
Anyone else encounter this? Advice?
At 138 pounds I'm also a lightweight. :) This really helps a stock displacement engine perform. I also live in a canyon and the first hill I climb every day from a dead stop is a 120 foot long 16% grade driveway. I modded my Grom for low rpm torque and it easily climbs it at 3,000 rpms without lugging the engine. I modified a DingerBuilt Long Intake to make it even longer.

T9K4Yx1.jpg

IMG_1087.JPG

I gave up top end high rpm performance so there's nothing above 8,000 rpms, but I'm happy to make the trade off in exchange for enjoying superb low rpm pull as I'm always riding steep canyon roads. :)
 

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Exhaust, alone will allow your bike to breathe better and build revs more freely. You're looking for low end grunt so you'll want a long exhaust with a near stock diameter not a short or large diameter race pipe. Intake may also help. You can also drop a tooth in the front sprocket at the expense of some top speed. But it's all relative. This 125cc engine is kind of a dog. There are 125cc Chinese pit bike engines putting out more power.
 

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Exhaust, alone will allow your bike to breathe better and build revs more freely. You're looking for low end grunt so you'll want a long exhaust with a near stock diameter not a short or large diameter race pipe. Intake may also help. You can also drop a tooth in the front sprocket at the expense of some top speed. But it's all relative. This 125cc engine is kind of a dog. There are 125cc Chinese pit bike engines putting out more power.
I'm running a very long 42 inch TOCE exhaust and a very short 16 inch IXIL so as to compare the two. The longer pipe does help the engine to pull stronger at low rpms, but to be honest there really isn't all that much difference between the two in daily riding. I believe it's the extra long DingerBuilt intake that is helping both of them to make more low rpm torque.

You're right. :)
Don't install an exhaust with a large diameter head pipe on a stock displacement engine. It not only slows down exhaust gas velocity, it ruins the laminar flow by causing the exhaust gas to tumble on itself negating the beneficial scavenging effect of the pulses as the exhaust valve opens and closes.



Both the TOCE and the IXIL hdead pipes are the same diameter, and even though there is a huge difference in length, they both work fine with a 125 engine.

KitKat, now many miles do you have on your Monkey? The engine runs much better after 1,000 miles or so. :)
 

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IMO the Monkey is over geared from the factory, and there's a big gap in gear ratios going from 1st to 2nd. Dropping a tooth on the front sprocket really wakes up the bike. It'll be a pretty rare day that you top it out while stock. Even with a full exhaust I've never hit the revlimiter in 4th, even going down a hill.
 

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but to be honest there really isn't all that much difference between the two in daily riding. I believe it's the extra long DingerBuilt intake that is helping both of them to make more low rpm torque.

KitKat, now many miles do you have on your Monkey? The engine runs much better after 1,000 miles or so. :)
It's all relative. When you start out with a measly 9 horsepower we're not going to feel much of a difference with any single, bolt-on mod, outside of a BBK, like we hope to. LOL


IMO the Monkey is over geared from the factory, and there's a big gap in gear ratios going from 1st to 2nd. Dropping a tooth on the front sprocket really wakes up the bike. It'll be a pretty rare day that you top it out while stock. Even with a full exhaust I've never hit the revlimiter in 4th, even going down a hill.
Does the Monkey have the same stock gearing as the Grom? I assume so because my stock Grom could never pull to the rev limiter in 4th gear.
 

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It's all relative. When you start out with a measly 9 horsepower we're not going to feel much of a difference with any single, bolt-on mod, outside of a BBK, like we hope to. LOL
You're right... the difference can only be subtle on such a tiny engine. I'm satisfied with the performance of a 125 because of its superb gas mileage and I don't want to ruin that.
 

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Gotta agree with 110% with Beatle in this one... sprockets are the cheapest easiest noticed torque helper on these little motors...it all helps but for under 20 bucks a 14tooth counter sprocket makes a noticed difference, and I can't hit rev limiter either.stock gearing I'd same as Grom...I've gone to a 37 on rear....and have 13,14,and stock15,I play with on countershaft....it's a blast with the 13/37combo!....but only runs about 45 safely on top end... So yeS. Drop to a 14 on counter shaft and don't look back... you'll be glad ya did!!! Speedo will read about 5 mph fast without a recalibrate..
 

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I'm 250lbs and while I'm not burning past cars on steep hills, I can maintain the speed limit (45ish) on even the longer hills. On the super steep hills, I try to plan for them. 95% of the hills I encounter are not an issue though.

Stock gearing, exhaust, fuel controller, intake, and cam.
 

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Ahh, I didn't realize the tire profile was different, but that makes sense. Stock Grom rear tire is 130/70 vs. 130/80 on the Monkey. That's a 5% effective difference in gearing. Dropping a tooth in the front lowers the gearing about 7%, so you're just about on par with a stock Grom's gearing. Bumping up a tooth or two in the rear may not be a bad idea since 14/34 is a pretty popular gearing on the Grom as well.
 
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