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Getting more bottom end from a 125 2 stroke.

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Hey I need some advice on getting more bottom end power from my rm125. It has vforce 3 reeds and has a scalvini pipe and silencer. It is jetted pretty much spot on for the altitude and setup. I was thinking changing the gearing or advancing the timing to get more bottom end out of it. Any advice?

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On 8/7/2017 at 7:49 AM, kjoyner233 said:

 

Hey I need some advice on getting more bottom end power from my rm125. It has vforce 3 reeds and has a scalvini pipe and silencer. It is jetted pretty much spot on for the altitude and setup. I was thinking changing the gearing or advancing the timing to get more bottom end out of it. Any advice?

 

A 125 MX 2T is not going to give any kind of bottom end power unless it is re-geared to the point that it has no top end speed.  That is what you will be trading off with this engine, bottom end increase vs loss of top end speed. 

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On 8/14/2017 at 0:13 AM, Pitviking said:

2 mm smaller carb,exhaust manifold spacer's.

I had a 36mm come stock on my CR125. Didn't make it a grunt master enduro crawling machine. There's only one way to ride the 125 if you want to keep any speed up: wide open with spastic clutching. 

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I agree to make a CR 125 move you would have to ride like a spaz,but the Suzuki has a half decent motor that can be made to work in different way's,the cr needs cubic dollar's to do anything.

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Not much torque gain but will make noticeable difference how clean a 125 runs on the very bottom :

 

-reduce the compression squish height

(reduced by 0.20mm on my YZ125 gained a modest 5psi but much crisper running engine)

 

-fresh piston and ring as soon as the compression drop 10% from the like new reading

-shorty silencer will add some 'hit' at the expense of top end / overev.

 

Check those VForce reed petals for proper sealing, often discussed issues with them....

Edited by mlatour

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My 2000 RM125 had plenty of bottom end for any crawling that I have done with it.  I say "had" because I am working on jetting to cure a top-end sputter/bog, and I've lost a little on the bottom at the moment.  Get your jetting correct, and it should have power from bottom to top.  It'll never make as much torque as a bigger bike, but they make plenty of usable torque.

I would recommend starting here, check the jetting tables, read up on jetting, and go from there

https://thumpertalk.com/forums/topic/656279-suzuki-2-stroke-faq/

 

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