NEED HELP with a 225dx problem

[TRImoto225]

I have a yamaha 225dx that was my grandfathers that i got when he passed away last august. it hasn't ran in years so when i got it i rebuilt the carb changed the plug coil/wire and checked everything out all over the bike first then started trying to start it. the electric start is bad so i have to pull start it. it will usually start after 3 or 4 pulls and will run really good at an idle and revs up at idle also but once you put it in gear and try to go it wants to backfire and die. if i flip the choke on it runs good but the more gas you give it it starts to do the same thing with the backfire and bogging down. any idea's what is going on with it. when it ran a couple years ago it ran good real good but sat for a while cause my grandfather got sick and wasnt able to work on it.

[Erics350x]

It sounds like a fuel problem. Did you drain and replace the fuel? The valves could probably stand to be adjusted. Pull the fuel valve and clean the screen. Also make sure the jets are perfectly clean, if you didn't replace them try running some fine wire through them to clear any build up.

[MTS]

sounds like crap in the carb yet.

[TRImoto225]

I've ran a real small wire through the jets and have rebuilt the carb twice and still have this problem there was no gas in the tank when i started messing with it. i put a clear fuel filter on it and the fuel looks clean. the petcock is stuck in the on position so i dont know if it is rusted or what i guess i'll put another fuel filter on and try to get the petcock fixed. What all is involved in adjusting the valves my grandfather used to do all the mechanical work on this and about 4 other 3wheelers we had but i dont remember how he did that he always had me cleaning parts and stuff plus i was too young and didnt want to pay attention on what he was doing i just wanted them to be done so we could ride? Can i adjust the valves or should i take it somewhere i've been working on cars for the past 10 years and can pretty much tear down and rebuild a chevy 350 while i sleep but when it comes to these little things i have no clue on how to work on them other than the carb work.

[smvorndran]

Take the gas tank off, and there are two access panels for the valves. Easy to get to, easy to adjust. Just rebuilt my top end last week, and they're easy to adjust. Now if I could only find a CDI to make it run.

smvorndran

[bigreddaddy]

I didn't see you mention if you checked the air filter. Could be clogged up. The exhaust could also be plugged up.

[TRImoto225]

thanks smvorndran
i'll try that saturday night.

bigreddaddy i have replaced the air filter after i first rebuilt the carb thinking that was the problem but it wasnt. as far as the exhaust goes i guess it could be clogged it blows exhaust out the end but when i first started it up the whole thing smoked for about 1min or so then then it quit every once in a while when i start it it will do it also but i just figured it was alright since it blows out the tail pipe. i'll see if i have another one for it and put it on and see what that does. i think my grandfather had a problem with the exhaust once before but not sure what happened with it.

by the way thanks for all the info guys
i've been asking alot of people about it but they want me to bring it to them and drop it off and leave it i dont feel real comfortable about doing that since it has some sentimental value. i'd like to try to fix it on my own since my grandfather was wanting to get it running this summer with me so i kinda feel like its something i have to do on my own so you guys have been a big help.

[bigreddaddy]

Can't the petcock be taken apart like Honda's? I've had some that were very clogged up with dirt and junk, especially the small filter in there, causing flow problems. You could also pull the fuel line off the carb and see if there is a steady flow of fuel for a quick check.
If its idling good but cutting out under throttle/load it could still be a carb/jet problem, petcock/flow, gas cap vent plugged, loose ground/electrical, valves.

Have you checked compression?

[bigreddaddy]

Don't some tri-motos have fuel pumps???

[smvorndran]

I don't know about the smaller Tri-motos, but the 200 & 225 are gravity fed. If you're having trouble with the petcock, buy a new one. The lever was snapped off of mine because it seized up, and obviously a crescent wrench will turn it.:crazy: Anyways, brand new Yamaha petcock special ordered at my Honda dealer was about $16.

Good luck. I'm cursing and screaming at mine right now because the CDI is shot. One just popped up on ebay, and I called the guy. I think he had one or two other people call him because he gave me the hint he wants $100 for it. The 225 CDI without reverse can be bought a dime a dozen, which yours probably is. I think you said yours was a DX, which was without reverse. The ones with reverse are rare, and so far no luck at finding a cheap one. It will sit in the back of the garage until I find a cheap CDI. Not to hi-jack your post, but would somebody out there be willing to try my CDI on their 225DR if I ship it both ways? I'm 98% sure it's the problem.

smvorndran

[Erics350x]

have you tried adjusting the mixture screw on the carb? also check the timing.

[Gag_Halfront]

I don't think that the mixture screw would be the problem because it idles and only dies out under load. By that time, you've got the carb cracked open and are pulling through the main jet.

To me, it sounds like a classic case of a gas cap that isn't venting. When they don't vent right, it will not be able to pull air into the tank as fast as you're trying to pull fuel out. That will cause a low pressure in the tank and restrict flow. It's a very tricky problem to identify at first because everything seems right. The float bowl will be full between runs, the floats will be adjusted right. You'll have good clean fuel and a good looking spark plug, but then you put the power to it and it dies out. What it does is under load it drains the float bowl faster than it can fill it.

Luckily, the test is both free and simple. Fire it up, loosen or remove the gas cap, see if it's better.

I really hope that's your problem because it beats having to tear anything else apart. Good luck with the DX! Oh... One more thing...


PICS!!! :D

[Gag_Halfront]

I don't know about the smaller Tri-motos, but the 200 & 225 are gravity fed. If you're having trouble with the petcock, buy a new one. The lever was snapped off of mine because it seized up, and obviously a crescent wrench will turn it.:crazy: Anyways, brand new Yamaha petcock special ordered at my Honda dealer was about $16.

Good luck. I'm cursing and screaming at mine right now because the CDI is shot. One just popped up on ebay, and I called the guy. I think he had one or two other people call him because he gave me the hint he wants $100 for it. The 225 CDI without reverse can be bought a dime a dozen, which yours probably is. I think you said yours was a DX, which was without reverse. The ones with reverse are rare, and so far no luck at finding a cheap one. It will sit in the back of the garage until I find a cheap CDI. Not to hi-jack your post, but would somebody out there be willing to try my CDI on their 225DR if I ship it both ways? I'm 98% sure it's the problem.

smvorndran

I have a DR that I don't mind experimenting on. PM if interested. My zip is 46304 to give you an idea what shipping would be.