Thank you, I will check the valve clearance soon and find out if they are in spec.

What do you think about the carb that I bolted on it? No one else mentioned a VM22 here that I saw. Am I also maybe running lean?

Thanks again!

 

Ok, according to my manual, you pull the timing plug and rotate the flywheel until the T mark lines up with the notch inside the plug. Doing that, both rockers are loaded and cannot be moved. Roll it past this point and the intake valve opens. Past that point, after the intake valve closes, both rockers can be moved easily and both have excessive clearance, certainly more than .004". Rotate the flywheel back to the T mark, and then both rockers are loose. I thought it had to be on the compression stroke TDC for adjustment? Well, whichever I guess.

My valves have excessive clearance. I'm having trouble locating my feeler gauge at the moment, but as soon as I find it I will reset the valves. This doesn't line up with my running issue though, does it?

 

Ok, found my feeler gauges. Set the intake to .003 and the exhaust to .005". Now it runs worse than before. Takes a lot to get it started, though the engine does sound smoother when it does run. With the choke on the idle goes up high and it seems to run fine. Choke off, the idle slowly drops until it stalls. If I snap the throttle it will keep running, but once it gets back to idle it slows down the RPM until it stalls if I let it, only takes 2-3 seconds. Choke on it runs high RPM but keeps running.

I'm thinking that means my mixture is lean? Lean mix should increase RPM though, but maybe not if the carb isn't feeding the engine enough. But I drove it before, when the valves were way loose. Now it has stalled and will not restart, choke or not.

 

Another update. I start it when it's cooled off, and it starts pretty easily. The idle goes up immediately from the choke being on, and I open the choke after a few seconds, and it idles great. Rev it up, and it kinda takes a second or two to get back to idle, for whatever reason, but it does idle. The idle speed is erratic, it'll idle good, then slowly raise the idle speed and hang there for 30 seconds maybe, then idle back down, then back up, all on it's own. Pretty soon, it will idle down but get too low, and I snap the throttle to keep it running. It will stay running as long as I do that. When I rev it, it responds quickly, but if I hold the throttle 1/2 way or better, after a second or two it sounds like a miss or something, backfiring into the exhaust kind of noise.

When it idles down, I adjust the idle speed screw to keep it at a stable RPM. This works for a short time, then it tries to stall again, so I set it higher, which again works for a short time until it tries to stall again. After it does stall with the engine warm, game over. It will not start again until it cools off. When it's cool, it starts right up and sounds great, until it gets warm again, then the cycle repeats. Are my valves too tight now? When the parts warm up the lash decreases I assume, maybe holding the valves open? This is kinda what it did before, but it is way more noticeable since I adjusted the valves, and it stalls in a lot less time than before.

Also, one other note - from my fuel tank is a black rubber hose, then my fuel filter, and after that is a clear hose going to the carb. I can see large air pockets in that hose travelling to the carb as it runs. I'm not sure why, it's not a suction system, it's gravity. Fuel tank is full, why is there air gaps? Regardless, feeding a float carb, the air should just rise and exit from the carb vent, right? That shouldn't have anything to do with my issue, right?

 

I'm at about my wits end with this pile of crap. Now it will restart warm today after it stalls, but it keeps trying to idle too low and stall. I adjust the idle stop screw and bump the idle up so it will stay running, then it stays running but way too fast for idle. If I let it idle fast for a minute, then turn the idle screw down, it will idle down smooth for a few seconds, then lope too low and die out. I don't know what to do. I'm about sick of it.

Anyone have any ideas?

 

Sounds like a jetting issue, or perhaps a vacuum leak.

 

I can't find a carburetor rebuild kit for a 85 Yamaha moto4 200 all I could find is 86-89 rebuild kits could the 86-89 work on a 85

 

Don't bother with rebuild kits. Only problem you get with carbs is worn float needle, the jets you can blow out with an airline and put back.

 

The bowl is leaking I went a head got one with gasket o rings