Arctic Chat

walkingcrow · 09-03-2007, 08:31 PM

I have my father's yamaha big bear at my place to get it running. The airbox had alot of gas in the bottom of it. I cleaned up the air filter and found out that the ignition switch was bad. He had tried push starting it. There was also alot of gunk in the carb. Anyway I checked the oil level then tried starting it and it started right up. The issue is as soon as I gave it throttle gas? oil? shot out of the crank case vent but it sure looked and smelled like gas. I assume that it was badly flooded. I will change the oil then start looking it over again. I was running it with the intake and crank case vent pulled off is it ok to do that or is that was caused the gas/oil to shoot out?
Does anyone know any good websites where I can get manuals, part no.'s etc for this bike? I think its an 1987 but I'm not sure yet just wanted to make sure it would fire up before I spent too much time on it. Right now the electric start won't work, it has cracked cv boots, and brake issues.

Thanks

WC

**Sanny651** · 09-03-2007, 08:42 PM

I would drain the oil again. Check to see how much oil it's suppose to take...might be less than the 2qts we typically take. Gummed up carb likely caused the float to stick which in turn flooded it out (especially while trailering).

miket · 09-03-2007, 09:28 PM

http://www.mrcycles.com/

Parts diagrams, part #s, and prices for japanese stuff. They go way back. I checked, and think I saw your machine. I actually used them for some Honda stuff -- as far back as '79. Good outfit, prices weren't out of line with the local dealer.
Hope that helps. Hope it's worth fixing.

Did those Yamahas have the oil volume stamped on the case in cc's like our suzuki motors? I did some work for a friend about a year ago, but I can't remember if they did. Good luck.

Mike

stroked · 09-03-2007, 09:48 PM

ya i would say you have a stuck needle in the seat i have seen so many of them on yamaha atv's and bikes over the past few years due to the very crappy fuel that we pay high dollar for i have had them so bad i had to use a needle nose just to pull it out i would replace it with a new needle and seat and also take the tank off and remove the fuel shut off valve and check to see how pluged your screen is on that due to the age of the atv . Tony

walkingcrow · 09-03-2007, 09:54 PM

where is the screen? It looked like it came out of the fuel shut off switch right to the carb.

WC

stroked · 09-03-2007, 10:30 PM

the screen should be in the tank on the other side of the fuel shut off valve unless it has been taken out in which case replace it with an in line fuel filter

lokimack · 09-04-2007, 06:30 AM

https://www.yamaha-motor.com/sport/myyamaha.../starthere.aspx

Sounds like the crankcase is overfilled with gas or oil. Does the crankcase vent to the airbox like our ACs do? Was it smoking or using oil prior to this? Could gas have washed down the cylinder or got into the airbox and then ran into crankcase through the vent from the carb being stuck during all the attempted starts?

I am sure all this has been thought of, but I figured I would just ask some questions and see if that snapped anyones thoughts on the matter. Best of luck.