Yamaha tri moto 225 dr

[518redneck]

I just picked this up. Clean the carb real good. Starts first pull every time. Idles great. If you rev it up it breaks up. I tried changing the cdi box to a dx. It worked but still broke up at high revs or steady throttle. The carb is at factory specs. Any ideas?

[Irideon3wheels]

maybe water in the gas tank? does it smoke? sometimes these old beasts have water get in the gas tank where it sits it works its way either through the vent or the sides over time. it might burn it off though. any thing else i couldnt tell you. ride it around at half to 3/4 throttle and see if maybe it clears up after a week. dont go full throttle though good luck!

[518redneck]

I drained and put fresh gas in. Also tried two new spark plugs ngk.

[Irideon3wheels]

then i honestly dont know i mainly work on honda's these tri motos ive been told have some old problems they never solved they just made a better attempt every time and now people who restore them realize why they left them be

[fabiodriven]

then i honestly dont know i mainly work on honda's these tri motos ive been told have some old problems they never solved they just made a better attempt every time and now people who restore them realize why they left them be

Come again? Problems they never solved?

The Yamaha trikes are every bit as good as the the Hondas in my opinion. These bikes ran great when they were new and will run great when in the hands of the right mechanic.

Redneck, you need to do a bit more diagnosis. You're not supplying us with enough details here to really help you. What you need to do is look at the machine, think about it, and do some wrenching. Don't do anything too far above your skill level, but at the same time challenge yourself. Do you have anyone around with a little more experience that can help you? It could be something really simple that just needs a little attention.

[518redneck]

What else do you need me to tell you? I rebuilt the carb and put it to factory specs. It has awesome compression. It's starts right up and will idle all day long. You rev it up to full throttle it acts like its skipping. You hold the throttle open about half or so it still sputters. I've checked the carb for dirt. I cleaned the tank and put fresh gas in. I have 3 200 Hondas 2 200x a 110 Honda and a 70 Honda and a tecate. I have been all thought the Hondas and never had this issue.

[bslama69]

Does it only sputter when you rev it in neutral or does it also do this when you ride it? If only in neutral and only at high RPM's it could be floating a valve. On older engines the valve springs can lose tension and at high RPM's the spring(s) isn't strong enough to make the valve close during the 4-stroke cycle (float). Having a valve partially open on the compression stroke is obviously not a good thing.

You didn't answer the earlier question if it is smoking or backfiring.

BS

[brd812]

might be a simple as a broken ground wire. When it revs it looses contact, you replaced the box right. Test the coil and stator, she may not be making enough juice. hopefully its something simple. I had pro design kill switch that did the samething on a quad that had me stumped, I threw a few 4 letter words at that machine for a while. just a thought

[Furno]

How about the clearances on your rockers? having a valve hanging open at high rpm's will give you a nice sputter and loss of power.

[518redneck]

No smoking or backfiring. It breaks up in neutral or in gear.

[518redneck]

I will check the valves tonight

[Furno]

How about the tensioner on the timing chain? worn chain, gears or a tensioner thats not doing its job can lead to all sorts of bad behavior. give the timing a check if you have a light and if you find the timing is off and you are going in circles to get it right, consider worn parts. Highly unlikely, but I've had it happen more than once, ya it was a totally different bike but the same principals apply.

There could be carbon or simply worn valves that arent sealing too. if you can check compression, you will see the bad valves while doing the check.

[fabiodriven]

It's definitely a good idea to check out the valves, but I'm guessing you may have a bad connection somewhere like one of the guys said.

[518redneck]

Well I check the stator and it's said I should have 196 I got 169 resistance. On the charginging It should be 381 I have 322. It this enough difference to cause this problem? Thanks

[Furno]

I'm surprised you got those values, more often than not you get crazy readings that make no sense. those values look fine. make sure each individual wire is plugged into your cdi properly, they come loose from the connectors sometimes. be sure you don't have a loose ground wire somewhere too.

[518redneck]

Well I had it running and and had it rev to where it was sputtering and I hit the Cdi box with a rubber end of a screw driver and the sputtering went away for a couple seconds then it came right back. I think the Cdi box is the problem and the book said that the Cdi my cause rapid misfire. I just wondering if the stator is to weak to make the Cdi work right

[518redneck]

Well I had the stator checked by a dealer and it checked out ok. I guess my Meter is broke. So I bought a CID box off the Internet and just tried that. Still about 1/4 to full throttle it breaks up. Rechecked the valves rechecked the timing and recleaned the carb. I don't have a battery in it. I was told by a few people that on these tri motos you need a battery to make it run right. Is that true?

[muthey]

no that's not true, the only thing that actually runs off the battery is the electric start. I have a feeling you have a ground issue somewhere on the trike, and the dr cdi's have issues all of their own, it might be possible to use a dx cdi, and see if that fixes your issues. Have you checked the w clip on the throttle valve to see if it is out of place and allowing the main needle to move improperly?

[518redneck]

I have tried a dx Cdi box and it has the same issue. I put a battery to it and that didn't help, I didn't think it would. I checked and cleaned up all the grounds and checked all others connections. I been through the carb a half dozen times and it seems to be clean and adjusted to factory specs according to the book. I was also told that there might be small cracks inside the carb where the main jet is, I can't see any. I recleaned the gas tank and put new gas in. I don't know what else to try other than a different carb maybe?

[swampthang]

Did you clean the carb or rebuild it? If you rebuilt the carb did you use the old main jet or the new one? The reason I ask is the rebuild kit for the dx is the same one for the timberwolf and beartrackers but with a smaller mainjet.

Check to see if there is any mud dobbers nest in the frame where the airbox draws in air up by the gas tank. Blow some air threw it to make sure. I have had machines act the same way and this was the problem.

As for factory specs on a 30 year old carb forget about it. Thats a good starting point but you will more then likely have to adjust.

[muthey]

have you checked for a plug in the intake tube through the frame, those run all the way through to the neck, also is your air filter clean or oiled? if nothing else try a new carb sometimes the carbs are just wore out it happens

[518redneck]

Anymore ideas? Keep them coming! I'm all out. I tried everything you guys post and what I thought of. I'm going to hopefully have a different carb this weekend. Mind I see is missing the main jet baffle plate. But I don't believe that's the problem. So anymore helpful hints would be appreciated.

[muthey]

no that is an atomizer, it helps keep the fumes limited so you don't vapor lock.I would definitely try a new carb and if that doesn't do it then there is a timing issue

[518redneck]

I tried a 22mm Honda carb and it has the same issue. Compression is low book says 114 min Its a little above 90. Im going to recheck the timing.

[518redneck]

Timing marks all line up. Took the muffler off to see if it's plugged. Did another compression check and this time it read right on the money at 125. Must of had a leak the last test. I think my next step is to try the stator and pickup eye from a parts dx.

[518redneck]

I checked the spark with a inline spark tester. It never lost spark when it acts up. I took the carb to a dealer and had a mechanic look at it. He said he didn't see anything wrong. If you watch the slide and needle as its running at idle then throttle it up it spits a lot of gas out of the needle/main jet. If you let off the throttle until the gas stops spitting out it will run fine. I tried a smaller jet. It still did it. I tried a different needle it still did it. The original needle is the correct one and it doesn't seem warn. I don't know why it's dumping that much gas in it. But it floods the motor right out. Any ideas?

[Rigaman]

I have a 225dx. There was a recipt from the previous owner that had the same problem. It said on the recipt that they noticed a wire getting pulled when the handle bars turned. Maybe check your wires and see if turning the bars put any tension on any wires.

[muthey]

I'm beginning to think you have an issue with your intake valve, or have you oiled the air filter yet? most of these 225 used a oiled air filter.

[trizilla]

how about an intake leak? like a torn intake manifold?

[yaegerb]

1/4 to WOT it is stumbling? It sounds like you have exhausted the electrical issues. Do you know if you have the stock jets in the carb? Have you performed any modifications to the three wheeler (air box, pipe, etc)? It almost sounds like your main is the wrong size.

[Rigaman]

Im telling you. Mine had the exact same symptoms. It was a wire getting pinched/pulled from the handle bars.

[518redneck]

I been through the wiring. Nothing it pullled to tight or broke. It has the stock main jet in it. The intake boot is ok with no leaks. For some reason it seems to flood itself out. The jet is 112.5. I tried a 105 jet it didn't make a difference. I had it running with the valve covers off. The valves seem to be working good. I'm hoping I can get another carb from a junk yard down the road. If this doesn't work there might be a dr for sale lol

[trizilla]

is the seat for the slide needle still in the carb? if that happened to fall out with out you knowing is would flood out no matter what jet was in it.

[518redneck]

I took a carb to another place and they adjusted the float. Brought it back home and still does it. I just don't get it. Next step maybe a weak intake spring and or a wore out cam? I checked for pinched or broken wires and found nothing. Keep the ideas running.

[splangeland]

As stupid as it sounds I would check your fuel shutoff valve. Mine was doing the same thing. I pulled it off and cleaned the fuel filter and still had no luck. It would run awesome as long as it was set on reserve. I bought a new one and wallah it ran good as new.

[Keepah Rolln]

As stupid as it sounds I would check your fuel shutoff valve. Mine was doing the same thing. I pulled it off and cleaned the fuel filter and still had no luck. It would run awesome as long as it was set on reserve. I bought a new one and wallah it ran good as new.

I 2nd this...Does you petcock leak at all?? If it does your sucking air. My yamaha did this as well as my honda on reserve though it would leak a couple drips of gas...

[518redneck]

I just want to thank everyone for there help. Who would have thought in 1985 Yamaha put a rev limiter on there tri moto. After cleaning the carb and going through everything I never tried to ride it. Stupid me I guess. Thanks again. Tecate project next!!!

[stickinto3wheel]

Glad you figure it out you helped me out with gettin mine goin

[Afrothunderkat]

I just want to thank everyone for there help. Who would have thought in 1985 Yamaha put a rev limiter on there tri moto.


HAHAHAHAHAHA I knew this was the cause as soon as I read the first post.

[Jwmajic]

LOL you got my sympathy. When i got my 225 I had a hell of a time with it before I figured out it had the wrong pilot jet and the former owner adjusted the throttle cable all the way to make it run so as soon as I started it after rebuilding the carb I thought it was going to blow. I would have never guessed it had a rev limiter.