need mechanical information on yamaha raptor

[tyandzoe]

My son has a yamaha raptor yfm50rt. It is idling fine, but when I put it in gear and give it gas it seems to loose power and die. I changed the oil, new spark plug and took off something to do with the fuel before it goes to the motor. i cleanded the air filter and thought about the carbuator but wasnt for sure I have the manual and read it,, but it says it may be a clogged fuel cog...but it doesnt say where that is. And I was putting grease in the fittings where the front pivots and the fitting fell off. Does anyone have a good idea on how to put that back on. I have a little common sense about motors but limited...pretty good for the mom... thanks for any help..

[Stoopidbot1]

Welcome to the site. You checked everything I would think of, there is a member on here that used to be a Yamaha Mechanic. I'll get him in touch with you.

[Raptor8]

usually when they cough and die under load it indicates a lean condition, like a vacuum leak between the carb and the engine. perhaps a little vacuum nipple missing? On those little buggers there is also a restrictor in ther intake [sounds like you found it] and not sure, but many had a restrictor in the exhaust as well, but these should not keep it from running... hmmm. Look at the 'safety swith' on the back of the bike where the lanyard is supposed to be. If there isn't a key in the switch it won't run over idle. I'll bet that is it. The switch has to be plugged into the harness and there must be a key in the switch [the key with the lanyard on it].

Sounds like you are very thorough, let me know what happens OK? happy to help.

What color was the working end of the sparkplug you removed? hopefully brown or tan.

[Raptorman224]

Well I'm not sure about how to put the fitting back on, but earlier today i was having the same problem on my Suzuki 80 (Dirtbike). What i did was clean the carb and cleared out some sediment build up and i blew air into the little pipes sticking out of the carb that. (they should be connected to clear tubes) to clear some debris out of that. It seemed to work for me but i'm not sure. Your jetting might be off or might be blocked with debris which would change your fuel/air mixture which might be causing that problem. "If there is blue smoke coming out the muffler, then either the rings are stuck in the piston or there is wear on the valve stems/seals or the piston/rings." Hope this helps, keep us posted : )

[Raptor8]

as for the fitting, hopefully it is just a screw in zerk, put it could be a push-in as well, does it have threads or barbs on it? you might put a piece of tape over the hole until it gets reinstalled just to keep the dust out...

Raptorman224, do you have any other ideas? I'm quite sure it's just a zerk, but don't rem if it is screw-in or push-in. Thanks for the help 224!

[Stoopidbot1]

You the man Raptor8, thank you.

[tyandzoe]

thanks guys for all your help. I looked at the fitting and it doesnt have any thread on it so maybe it just broke off in there. I guess I could try to get another one and push in...I did notice today that the plastic thing that conects the lanyard is broken and hanging down... I am going to try to mess with that in a while...great advice...

[tyandzoe]

the spark plug i removed was dark brown and the new one that I just put in and took out and looked at was black. I took a metal brush to it and put it back in. I guess the black color is from miss firing????

[SunLrider]

the spark plug i removed was dark brown and the new one that I just put in and took out and looked at was black. I took a metal brush to it and put it back in. I guess the black color is from miss firing????

to my knowlage you are guessing right

[Raptor8]

black is too rich, too much fuel, hard to do at idle.

if it's not the safety switch then we have a carb problem.

Sorry, it's impossible to diagnose by telepathy.....

[Stoopidbot1]

No, you were right about the safety switch. Now she's trying to figure the next problem.

[Raptor8]

well that is certainly good news! I don't know about that fitting problem, I thot all those front ends were sealed. Perhaps a picture from a parts catalog? that would help greatly.

Most larger dealerships have catalog access, like chaparral, pro-caliber, etc. I use pro-caliber since I used to work there [before it was pro-caliber.]