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-   -   XT225 No power at low revs (http://www.horizonsunlimited.com/hubb/yamaha-tech/xt225-no-power-low-revs-51951)

Alan C 9 Aug 2010 04:20

XT225 No power at low revs

I have an XT225 that is fine at high revs but at lower revs suffers from a huge lack of power. I have to slip it into first gear to get up the steeper hills even with just me on the bike (80kg). I used to be able to get up those hills in 2nd or even 3rd gear before.

I don't know if this is related or not but it also has problems starting from cold. Fortunately I live on a hill so it is very easy for me to bump start it. It coughs and splutters for the first 100m but then it is ok though it does have a tendency to die if I don't keep the revs up a little.

The trouble is that I live in a sleepy little place in Thailand and the mechanics here don't really have much of a clue regarding bigger (imported) bikes. And, to be honest, I am not the most mechanically minded person either.

Does anybody have any ideas?

Many thanks.

bobthebiker 9 Aug 2010 04:39

several things to check. first is very simple. check your sparkplug, replace it is probably the best bet.

next, is the carburetor. it has two important jets in it, a main, and pilot jet. the pilot jet basically runs things from idle to about 25% throttle, give or take, and the main is from there on, or a certain engine speed and above.

if either,or both are dirty, you're not going to have a good running bike. remove and blow them out if you can with an air compressor. if you cant see light through them, they arent clear.

also clean the bowl of the carburetor as well. any dirt or sediment in there, will get stirred up while the bike runs, which will result in poor performance and rough running/lack of power.

also, have the valve clearnces checked. its a pretty simple job, but must be done with the motor cold, like dont even start it in the morning kind of cold. a valve out of spec will make a bike lose power if it isnt sealing entirely. easy adjustment.

oothef 9 Aug 2010 11:11

Check the air filter, just remove it and see how it runs- better or worse?
Have a good look at the inlet rubber between carb and head check for cracks or splits.
Poor starting points to weak running, air leaks or blocked jets, first things to check.

bruken 9 Aug 2010 15:19

Sounds to me like you may be running too rich and the bike is bogging down under low rev load. Check the colour of your plugs (biscuit brown is good, black is rich, whiteish is lean) and adjust the pilot needle / float hight accordingly. A give away is if blipping the throttle in neutral you produce excessive brownish smoke from the exhaust. Other than that check your coils are not breaking down under load.

Alan C 10 Aug 2010 08:22

Thanks very much guys. Will try to check these things out asap. Cheers.

Flyingdoctor 10 Aug 2010 08:55

Alan, you need to post your questions on XT225.com.

These guys have a lot of experience in setting up your bike. They come from the factory set very lean. There are simple mods to rectify this as well as information on getting the jetting right for riding at altitude. give them a try.

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