1992 Mtx125 Running Problems.

[frazer1981]

Hi,

I have a 1992 honda MTX 125 on a j plate. When i got the bike it had been stored for 3 years. I drainned all the fuel,oil, coolent etc etc and refilled before rideing it. I noticed stright away that it does run properly in lower gears. In 1st,2nd and 3rd it runs really rough and in 1st it only revs to 5,000rpm and no more where the power comes in at 5,000 rpm in 5th,4th and 6th. 1 thing i have noticed is that it smokes alot, and it drinks both fuel and oil like no bodys business.

A have done a few trips on the bike out and about and have noticed that a full tank of 2storke is not lasting more than a week? Could this be pointing to some thing major going wrong in side the engine??

Also i am looking for an after market exhust kit for it as well but want a complete kit of frront pipe and silencer as well. Does anybody know of a company that makes these and also how much roughly this would cost me ??

Thanks

[StumpyFingers]

Check the air filter and timing.
Restrictive air flow causes the symptoms as you describe.
Plus timing out by a hair will also cause the same problems

[frazer1981]

That is a point actually air filter!! have'nt even looked at that since i got the bike. Timing??? Is that not a 4 stroke releated problem??? I know ignition timing on olderbikes is a problem because of the points but as far as i know this bike should be cdi ignition or am i wrong? How would i check the timing ?? Also the spark plug is very black so i think it is burning oil? Thanks for your help so far

[StumpyFingers]

You say it is Two stroke therefore the oil will be mixed with the fuel.
Black plug means rich mixture , not enough air.
The timing could be out on cdi if the sensor is misaligned or loose.

[AIRWOLF]

Presuming the oil is fed by a 'posilube' system (seperate tank for oil), the smoke and black sparkplug may indicate the calibration of the pump is out, ie. feeding too much oil into the fuel.
Your workshop manual will tell you how to check/set up.

[chronyx]

Yup this happened on my CRM.

[frazer1981]

Thanks for all the help here guys, i am just waiting for my workshop manual to arrive so i can check the oil pump. I will try and post some pictures of my bike when i get the chance.

[russh]

May sound daft, but have you changed the spark plug. 2-stokes eat plugs for breakfast. Many a time I've fixed rough running with a new plug.

[frazer1981]

I have but it never really made a differance. I have got another one which has not been used yet so i am keeping that one untill i get my manual and try and sort things out. I think my exhust my have something to do with it as well as it is the orignal system which has just been repacked over the years. It sounds good but i am looking for an after market system which i can fit on with out making jetting changes. I would like to change both the front and rear sections of the system. Does any body know who makes a full system for an MTX 125 ??

[logic0404]

yea big one exhausts do a front and rear exhausts for the mtx 125 there are about 90 for the front pipe and 60 for the rear but the complete system is about 140 of www.dirtbikestore.com . i jus got the front pipe and brought a dep silincer of dirtbike store. wemoto (jus google mtx 125 parts) also do loads of spares for this bike. these were the main places that i could find hope this helps