How Low Can I Go? Ouch Not that low! Help

[indicaz]

Hey everyone,
Im really tired of falling, flying, tumbling, twisting and being a human test dummy on my 125 and I can only attribute it to one damn thing, Low end.
Ok so my 97 rm125, is fast in the top and mid range however to get up even the shortest of steep embankments if im not moving at atleast top of 1st/2nd speed i usually will bog out unless I rev the bike high and flutter the clutch a bit, however this cannot be done from a stand still like on many other peoples bikes and it does not always work.... and yes ofcourse I know a 250 can do this without a problem. I dont have a 250 though :) ok please dont say go get a 250 :) ,


so basically i was wondering what I can do to improve the bottom end , now honestly I could do away with some of the top end mainly because this bike isnt being raced, rather I just ride the trails and kid made tracks around my house. It seems the original owner of this bike may have raced, as the bike seems totally tuned for a wide open space.

From my understanding, changing my pipe could help, along with a tooth or 2 lower on the sprocket? I also read that jetting can also improve this.

Can anyone please suggest how I can improve the low end?

Thanks

 

[ctdyno]

2 teeth LARGER on the rear sprocket may help you, and there are some expansion chambers that are more for trails than mx, these may help you, as well as a flyweel weight, reeds are also supposed to help but i havent ridden anythign with different reeds so i cant say anythign definite about that

 

[_JOE_]

Before you go and spend 400 bucks on a pipe and silencer, call Eric Gorr and have it ported. Jet it afterwards and you'll have a much better woods motor. If you have any money left over, look into a flywheel weight. Those are two of the best bang-for-your-buck woods mods.

 

[sick 96 250]

some of the above mentioned thing will help out some like the upping the rear sprocket teeth, port work etc but hate to say it 125's aren't really trail friendly. Somehow my buddy rips fine through the trails with no issues on his 95 RM 125. Do you have any mods done to the bike like pipe/silencer combo or anything? Some pipes are different in many areas where as some are for higher RPM's and others can smooth things out some all across the power curve. For now your just gonna have to REV the heck out of the bike and keep it under control.

 

[76GMC1500]

Before you spend any money, make sure your power valve isn't hung open.

 

[indicaz]

Bike has a fmf fatty gold pipe, vforce 3 , and a renthal sprocket... a bunch of other goodies as well

I purchased the bike used from a very cool dirtrider member and it appears to have alot of modifications done to it. The top cylinder sleeve/head has the initials MT acid etched into the metal... I am not sure but the cylinder head may already be modified I have no idea without taking it apart... but it deffinietly looks to be different.

I have noticed the bike has a nice powerange that tops out on each gear from 1 -3 fairly quickly once you get higher ofcourse the range becomes longer... however the bike seems to be just that all top end... in the low and lower mid range it just isnt very responsive, i find myself stuck more then id like... It takes alot out of ya having to push yourself out of a ditch.... kinda ruins the ride.


Power valve? didnt thinkof that Thanks for the tip ill have to look into that

I have kept up on basic maint... air filter, lube, cleaning and such I have yet to mess with any of the jetting or tuning of the motor as I have no idea what im doing and the person who sold me the bike mnentioned something about a different needle that was added to the carb...


By all means this bike rips... sometimes too fast... i would so sacrifice speed on this bike for some power!! the bike is totally setup in my opinion for freestyle motocross or some wide open supercross track or something.

I really am starting to begin to understand why I really should have a 4 stroke..


I will look into the options mentioned! thanks alot guys

 

[blackedoutcr125]

have your cylinder head ported and polished, its usualy called the "cylinder head mod" it adds low and mid end range power, and adds a smoother more agressive punch to the throttle, its just what your asking for and will cost you a 100 bucks to have done and does work well. It also adds more compression.

 

[sick 96 250]

I would ask the previous owner exactly what was done to the motor? If someone etches their initials into the head or somewhere normally that means motor work has been done such as porting or something else.

 

[rpm12505]

Try 1 tooth smaller on the front sprocket. It's a big jump but the cheapest way to tell if different gearing will help. Front sprocket about $15. Rear about $60.

 

[indicaz]

ok i checked the exhaust valve this evening. the adjustment portion of it seems to be all good, i removed the faceplate removed spring and tested the valves movement but manually turning them, they moved freely, i replaced the spring, dial etc and turned it 1 turn out as the factory manual suggested and then re tightened faceplate.

Seems the power valve/exhaust valve is in order.

Counted the front sprocket I believe I counted 12 teeth, i havent counted the rear yet

I also agree that it seems that someone wouldnt etch there initials into the cylinder head unless some substantial work has been done to the motor.

Without taking the cylinder head off I will have no idea... Doing this I will guaranteed at minimum need all new gaskets to re assemble plus I will need a measuring tool of some sort to measure the cylinders bore?

Its so weird because I actually am starting to think my bike is a 250 Frame with a heavily modified 125cc motor plopped into it... is there any way i can verify this via the stamped VIN?

This would also explain why when i recently purchased new plastics the fit was kind of strange LOL