honda crf70 power loss

[evo79]

hi all working on my daughters honda 07 crf70.she complained of power loss,so i started going through all the things i know of, sparkie replaced,oil replaced,carbie cleaned,jets checked and cleaned,values checked and adjusted,it starts runs but has no power when in gear and blowing alot of smoke( yes that might be part my fault as i did over fill to start with then dropped oil out and refilled to correct levels).im starting to run out of options.even thou it has decent compression behind it when kicked over should i be looking at worn piston and rings?hope you all can help me figure this out and cheers in advance

[Go Big Red]

hi all working on my daughters honda 07 crf70.she complained of power loss,so i started going through all the things i know of, sparkie replaced,oil replaced,carbie cleaned,jets checked and cleaned,values checked and adjusted,it starts runs but has no power when in gear and blowing alot of smoke( yes that might be part my fault as i did over fill to start with then dropped oil out and refilled to correct levels).im starting to run out of options.even thou it has decent compression behind it when kicked over should i be looking at worn piston and rings?hope you all can help me figure this out and cheers in advance

pull the plug out of the end of the exhaust and clean.  the spark arrestor screen can get blocked by carbon, especially if it was smoking due to an over fill.  also clean/replace the air filter.

 

what was it running like before?  did it smoke at all then?  

[ohiodrz400sm]

Did you ride it? Is the clutch slipping?

[evo79]

Hi there is no clutch and thanks red will look at that. It would smoke just a tiny little bit nothing like it is now

[ohiodrz400sm]

Hi there is no clutch and thanks red will look at that. It would smoke just a tiny little bit nothing like it is now

There in fact is a clutch. It is operated by the shift shaft instead of a manual lever, hence the term auto clutch. They wear out and slip just like a big bike.

It also needs adjustment from time to time.

Edited January 22, 2017 by ohiodrz400sm

[evo79]

Yeh I was just thinking clutch lever. Yeh gears are all good not slipping at all

[ohiodrz400sm]

That bike doesn't have alot of power to spare. Did you check to make sure the brakes are not hanging up or dragging?

[Go Big Red]

That bike doesn't have alot of power to spare. Did you check to make sure the brakes are not hanging up or dragging?

this is a good point.  if that back brake is dragging it will cause some issues.  it should spin freely

[evo79]

Yeh all good with back brakes. I'm starting to look at piston and rings which I'm going to replace in the next few days