Yamaha Four-Wheeler Won't Start

[MTboatguy]

Re: Yamaha Four-Wheeler Won't Start

As far as figuring out the year, it is best to get the frame number, call your local Yamaha dealer and see if they can pinpoint it to a year range for you, it is amazing how many engines get changed in these things. If your state does not issue titles on ATV's it is going to be hard to figure the exact year out.

 

[csprain]

Re: Yamaha Four-Wheeler Won't Start

Okay, I'm fairly confident its the original motor. I got a compression tester but then the fittings weren't right so I will have to get a different one. I cranked with the plug out and a lot of fuel came out and shot 4+ feet. Seems like it way more fuel than what should have been in there.

 

[MTboatguy]

Re: Yamaha Four-Wheeler Won't Start

If fuel squirted out, then you plug is not firing, you either need to change the plug or make sure the coil is firing. If you had that much fuel squirting out, you are never going to get it to fire, that much fuel means the plug is bathed in fuel, no matter how much fire you have in a closed space like that it is not going to run, it takes air and fuel to fire, you have way to much fuel. You need to check that carb again, and I don't care if it was rebuilt, something is way off.

Way more fuel, I would say, it sounds like you are not getting any air at all, now, if you do get it straightened out, you are going to need to change the oil, if you have that much fuel, then you are getting a bleed down situation and the fuel is going to dilute the oil in the crank case, at this point in time it would be best to get a manual and figure out how to take that motor out, clean it out and start over.

 

[Tim Frank]

Re: Yamaha Four-Wheeler Won't Start

If this was a 2-stroke O/B forum I'd be banging the "check compression" drum hard....if this is a small 4-stroke engine, you said you changed the oil and filter, then it is just as important....maybe more so.
Lack of compression can have a few extra causes in a 4-stroke, valves for 1, and any of them will stop you dead.

 

[MTboatguy]

Re: Yamaha Four-Wheeler Won't Start

The timberwolf is a 4 stroke motor, here is a link to the specifications for that bike:

Yamaha Timberwolf 2x4 Specifications: Off-Road.com

As Tim mentioned one very important thing to check in these bikes is the valves, they need to be adjusted correctly or it will not start. You need to get a manual that explains all the procedures on this bike.

 

[Bob_VT]

Re: Yamaha Four-Wheeler Won't Start

Okay, I'm fairly confident its the original motor. I got a compression tester but then the fittings weren't right so I will have to get a different one. I cranked with the plug out and a lot of fuel came out and shot 4+ feet. Seems like it way more fuel than what should have been in there.

Once again I yield to and agree with what MTboayguy has said. If you are getting that much fuel spitting out then something is wrong in the carb. If the float needle is adjusted wrong or it is sticking open you are flooding the motor. Look at the frame by the steering column for the year.

At this point..... I would re-build the carb again.

Another option to see if it will fire is to dis-connect the fuel line, remove the plug and make sure it is dried out of old fuel. With the fuel line removed try squirting a small amount of fuel into the carb and try to start it.

And yes....with that much fuel .....plan on an oil change.

 

[csprain]

Re: Yamaha Four-Wheeler Won't Start

I can definitely do another oil change. I found the reason I was getting so much fuel the adjustment on the carb was too high. I turned it way down and the fuel is coming out like it should be. The fuel was shooting out so much when I had the spark plug out, I believe I got the combustion chamber pretty much cleaned out of fuel except when cranking it mists as it should. I have the haynes manual for the four wheeler. So I guess the next thing would be to check compression, valves, and an oil change? I really do not want to pull the motor out. I could do it, I've done it on cars before but I dont want to pull it if I could avoid it and get it started.

 

[csprain]

Re: Yamaha Four-Wheeler Won't Start

I finally got it started today, float in the carb was stuck, idle/air adjustment was off. Inline fuse was too small so I blew it and now the battery is dead. But I guess recharge the battery, new inline fuse, and an oil change I should be on my way. Only question, why is gas still come out of the line at the bottom of the carb?

 

[MTboatguy]

Re: Yamaha Four-Wheeler Won't Start

If there is gas coming out of the vent on the bottom of the carb, then something is still messed up in that carb, have you done a google search on this particular issue? I still have an extra carb around here, that fits that engine, I will take a look tomorrow and see if I can figure out why it would be leaking.

 

[AK_Chappy]

Re: Yamaha Four-Wheeler Won't Start

My Kodiak will do that. There is a drain for the fuel bowl on the bottom. The screw gets a "ridge" in it that prevents it from sealing properly. I have to turn my fuel off when I am done riding and then it takes a little bit to fill the bowl again when I am ready to ride again later.

AK Chappy

 

[rbh]

Re: Yamaha Four-Wheeler Won't Start

Most times my carb leaked was because of a poor needle valve and seat, but check the height of the float and adjust the tang that closes the needle.
Is there any build up of junk in the seat or on the needle valve (rubber tip should be clean and no wear marks)