New Yamaha Tri-Moto YTM200EK owner & I have carb problems! Please help!

[eBoyDog]

Hello, I'm new here and my main reason for joining is that I recently bought a 83 Tri-Moto 200 (YTM200EK) and I'm having a big problem in getting it running.

When I bought it, the seller claimed it runs, said the battery had been dead for some time so he would always just jump start it off his truck to get it started; when I went to see it before buying it he had the jumper cables hooked up to it but the throttle cable broke and he couldn't get it started. Despite that I ended up buying it, he was asking $400 and I ended up paying $200 for it. All the plastic it good and other than lots of mud on it, it's looks good.

Well now after a couple weeks, I have ordered and recieved a few parts for it, a new throttle cable, carb needle valve (carb was leaking fuel from it's overfill port), a carb bowel gasket and few other things such a oil filter brake pads, etc... Also put a new battery in it.

Now I got the throttle cable installed, replaced the needle valve and seat, adjusted the pilot screw per the Haynes/Clymer service manual I found online yet I can't get it running yet. The best I have gotten is a slight fire and a brief second perhaps two idle.

I have experience in small engines esp garden tractor type but limited ATV/ATC motorcycle stuff but I have done basic stuff like change/gap spark plug, dumped the gas out and replaced with fresh fuel, also I have taken the carb apart and cleaned everything including running wire through all the brass port jets making sure nothing is blocked and sprayed carb cleaner though everything then reassembled it all.

Can anyone offer suggestions of what to do next or what I might check next? I have a spark tester so I checked that and it has a good spark. This Yamaha has a Mikuni VM22SH carb, I have searched all over the internet in search for technical support of such and found some info, mostly jets kits for high performance racing and tuning but nothing really as far a basic help.

In taking the carb apart, there wasn't a lot of crud or deposits so it's not like I'm working with a basket case so is there anyone out there with any ideas? It doesn't seem it should be this hard to at least get this trike running!

Thank you in advance!

[Oman14]

Are you running it with the airbox attached? If so try to start it with an open carb. I had a similar problem and it wouldn't run with the airbox on hell it wouldn't run with just the hose on! Ended up being the air flow screw. I have it set about 2 1/4 out from all the way tight. Also try taking the carb complete apart and place all the metal parts in a tub and let it soak in carb cleaner over night. Don't soak any plastic in the carb cleaner as it will ruin it!

[eBoyDog]

I got it going, took the carb apart again and recleaned everything, I believe the issue was the pilot screw port in the carb body, I missed that the first time and after reading how the jets/ports work in three parts, I used a torch cleaning wire to make sure everything was open and clean.

It runs well now, only problem I see so far now is the head lights as while they work, when I turn the key switch to "lights", it kills the engine and turning the key back to the center the light comes on. As the tail light doesn't work, I'm thinking there is a electrical problem some were. After deer hunting season is done, I have to tear into it and see it I can figure something out.

[Oman14]

Uhh Idk if I understand you right. But if you turn the key to "lights" that mean lights only it's like turning the key off for the rest of the trike. Here is a wiring diagram just in case http://www.3wheelerworld.com/content...iring-diagrams

[eBoyDog]

From the manual, it states that when the key switch is in the on position, the trike will start & run. When the key is switched to the light position, the head light and tail light should come on while the engine is running (if the light switch on the left handle bar is in the high or low position). When I turn my key switch to the light position while the engine is running, the head light come on, the tail light never lights up and the engine dies. The engine shuts off when the key switch is in the light position regardless of the position of the light switch on the left handle bar.

Thanks for the wiring diagram, I have one in the user manual which confirms what you provided, I haven't had the the chance to start tracing wires, My guess is that either the key switch is bad or replaced with the wrong type or the light switch control on the left handle bar is bad and it's shorting out with the engine kill switch since both are located on the same switch assembly.

The light problem is mute right now, I messed with the carb again since it refused to start in 40 degree or colder weather and now it's not running or starting at all as I messed up the pilot screw o rings I think. I have what I hope is good used carb being shipped to me that I should get in a couple days which hopefully will cure my starting ills. The carb I getting came off a 225dx which the mid range jets might be little bigger than than my 196cc trike should have but I'm confident that the start pilot jets are good at least if the youtube video of the seller is true. http://www.ebay.com/itm/231102492563...84.m1439.l2649

I'm disabled and can't walk very long distances or pull deer out, this cheap little trike is my way into the woods for deer hunting so I must have reliable starting in cold weather as If I get stuck with a dead trike, I'm stuck with no way to get me or my deer out!

[eBoyDog]

Well I'm back to carb "blues", I reworked the carb and now I can't get it to even start. I have a replacement used carb coming in hopefully today which came off a 225dx but other than perhaps the jet sizes, should work...

[eBoyDog]

BTW - does anyone know how many orings are in the pilot jet on the Mikuni VM22SH carb? the parts diagram is low res but it appears there are 2 on the top, then the spring and perhaps a another but it's hard to tell. I wish I could find a better diagram or pic of the actual oring and spring assembly on the pilot jet.

[emmie357]

Don't quote me... but I believe it's one O ring and a small metal (maybe brass) ring.

[muthey]

on the pilot from the screw going in it is sprint metal washer, and o-ring. Also with yammie's when you turn the key to lights it only runs the lights, I always mod my keyed ignitoins to the two setting style, which doesn't involve breaking or changing anything just a little dis assembly and of the tumbler system and rotating the tumble system 180* to the other position. Did you replace the float needle seat and o-ring, if not check the o-ring on the float needle seat if it goes bad it will cause a flooding issue, also in the float bowl there is a jet directly down from the choke that is called the starter jet check that to see if it is plugged. Mikuni carbs can be very picky sometimes and others very simple to resolve the issues.

[eBoyDog]

on the pilot from the screw going in it is sprint metal washer, and o-ring. Also with yammie's when you turn the key to lights it only runs the lights, I always mod my keyed ignitoins to the two setting style, which doesn't involve breaking or changing anything just a little dis assembly and of the tumbler system and rotating the tumble system 180* to the other position. Did you replace the float needle seat and o-ring, if not check the o-ring on the float needle seat if it goes bad it will cause a flooding issue, also in the float bowl there is a jet directly down from the choke that is called the starter jet check that to see if it is plugged. Mikuni carbs can be very picky sometimes and others very simple to resolve the issues.

But shouldn't the taillight light up regardless when the engine is running and the headlight can be turned on with the controls on the left handlebar (off/low/high)?

[eBoyDog]

Oh and the carb issue's are still haunting me, it starts fine in the heated garage with no choke necessary but if it get's a little chilled, it's a no start issue. I replaced the oring on the choke to see if that helped and I think it did as I believe my problem is that the choke is getting stuck as the cable doesn't move freely; I'm thinking about getting a manual choe conversion kit to do away with the cable but I haven't checked to see which is cheaper, the kit or a new cable. I put new jets in it and it runs great, it just doesn't like cold weather starting unless I stick a little heater under to engine to warm it up a little before I try starting it.

[muthey]

I believe the tail light runs off the motor all the time, the light selection is for if you need just the headlight to see what you are doing and don't need the trike running. Which will explain why your head light doesn't work on on position and your tail light never works, your lighting coil is out. Because in run position with the key the only thing the battery runs is the neutral light reverse light and the starter.definitely ohm the lighting coil on the stator. Now for the carb the choke cable is about 49.00 - 69.00$ from a yamaha dealer. I lucked out and got one from ebay for 39.00$ for my dx a couple of years ago, but the dx one is a 29u and shorter, the one you need would be a 24w and a few inches longer.

[eBoyDog]

I'm updating my progress on my YTM200Ek and it's starting problem.

In a nut shell, it wasn't the carb but rather a weak/bad ignition coil, after using a ohm meter to test the old one and finding it it wasn't good per the Clymer service manual specs. I bought a new one and after putting it on it fires up right away including starting with one pull on the rope starter.

[webbch]

Did you try clipping a tiny bit off the end of the old spark plug wire to give it some fresh wire to grab onto? Unless the YTM200 is different, I think you just unscrew the spark plug boot from the wire, and clip off a bit. That may have been the problem with the old coil.

[eBoyDog]

Did you try clipping a tiny bit off the end of the old spark plug wire to give it some fresh wire to grab onto? Unless the YTM200 is different, I think you just unscrew the spark plug boot from the wire, and clip off a bit. That may have been the problem with the old coil.

Yep that was the first thing I tried, I also had 3 coils off my part machines and none of them helped at all, I guess after 30 years some parts wear out. , I suspect the other end of the plug wire was bad were it goes into the coil but I found at least on the stock coil, that end isn't suppose to come off. I found eBay seller who had them for about $22 shipped, new one didn't include plug cap but that wasn't a big deal, I did add heat shrink tube to better seal the plug wire ends. If this lasts as long as the stock coil, the the cost will be nothing, I assumed there would be high performance coils available which while I didn't look too hard, I didn't fid any.

My weak bad coils had no resistance in between the primary and secondary (the wire going to the car and the sparkplug end) new one does but it's not the same ohm spec that the Clymer manual States there should be but I can't argue with success.

The tests suggests looking for thick blue sparks which my old coil I thought had but in checking the new coil they meant a REALLY thick blue spark! I had spark, just not a strong enough one.