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Got a 1980* yamaha XT-250,.. with problems.. Can anyone help me out?

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Alright! Got a 1980 XT250 in a trade and I already love it.

My bike is like a young prom date and is NOT not putting nearly as much as I'd like it to!!

The wiring is pretty hacked up so ive gotta get a diagram and try and sort it out.

I believe it's a spark timing issue possibly-maybe-hopefully?

It feels like it's redlining at super low engine speeds on flat ground and when going downhill it just backfires and seems to be.... idk..... just all around effed in the A?

When lugging it in too high of a gear and going uphill you can actually give it half to three-quarters throttle and it runs beautiful with power to spare.

Plug looked like it was burning good, a little on the lean side maybe,,,, It doesnt have an airbox either! just a filter on the end of the carb? (either he never got it when getting the bike.... OR! Wanted a cold air intake like-2-Fast-AND-Furious-VTECHHH-honda-civickkk-g0-f@st-ebay-NOS-diggity-dog!!!!!!!Ftw!)???

But I dont think it's excessively lean, and running with the choke doesn't help it run better...

almost acts like its running rich,

]Already switched the plug....

if]I think the main clue is it doesn't back-fire when lugging and giving it the gas going uphill...

Please help if you have any idea?

I really wanna ride in this B-E-A-U-TiFuL weather!!!!

and my bike is acting like a diesel.

I thought valve timing seemed good because the bike has LOADS of compression!

It starts the first or second kick and runs great as long as the choke isn't o or you don't rev it up too much...

It's a 1980 btw according to the tag on front of the frame ]I think the Mono shock under the tank is a very aesthetically pleasing to see...

Kind of Retro-predicting-futuristic kind of thing....[/font]

Ive got a multi-meter, any tests I should run before I start blindly digging into it?

The stock silencer is pretty beat up, but Ive actually got an 88 Kawasaki ninja 250 parts bike....

The right side silencer for the exhaust is looking good as far as mounting up with hardly any real modification,

I figured in case the stock one is plugged,,,, looks like someone used a chisel and a rock to remove the baffles!

The foot pegs (passenger pegs for the ninja) actually mounted up well on the stock brackewt for the XT250, being a little longs and like half the weight from stock..... And they look pretty trick. ithink.

So yeah, if anyone can help I'd be forever greatful.

Edited by B Dirty

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is the accelerator pump working correctly? those where manual and if the diaphragm is split it might do what you are saying. with the carb off the bike, it should squirt gas a couple of feet with gas in the float bowl.

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I'll take tha carb off and go through it!!!

I saw that it was manual and that when I'd give it gas the little rod would move to punp more gas in!

I'll check that and take the carb apart....

Ive got to get ahold of the guy and see what new parts he put in the engine.....

Maybe he put a part in wrong and thats why it's messed up....

The timing chain looked BRAND SPANKIN NEW with no slack in it.....

I'm gonna do the carb in a few minutes and I'll let you know what the news is with that.

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If the carb is not pumping there is a small ball and spring in the bottom part of the carb. (This is a check valve)This is not meant to be serviced. Drill the brass plug with a small drill and tap the hole. Leave the tap in and carefully remove the plug using heat. Once out flush out the passage. With a punch gently hammer the small bearing to seat the bearing. It only takes a gentle hit. Put spring back and put brass plug back. Close the hole with a small bolt, I cut the bolts length to about 1/4 inch.

This got my carb working, the diaphragm on my carb was in good shape. I watched the mechanic do this on my carb. The carb was from a 1981 xt 250.

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