YZ85 running super rich.

Related:
Create New Tag

7/29/2019 1:40 PM

I picked up an '02 YZ85 for my boy and have been fixing it up for him. It's got a new topend, air filter, carb's been gone through. All the jetting is stock and in the video the needle is clipped at the leanest setting. Fuel is premium @ 32:1 synthetic oil. I don't know what's going on but it's unrideable. Bogs all over the place and you have to work it to keep it going. Smokes like a fog machine. Any ideas?

|

7/29/2019 1:54 PM
Edited Date/Time: 7/29/2019 1:58 PM

that’s a lot of smoke.. if everything else is new, bad right side crank seal would be be my bet....

|

7/29/2019 3:42 PM

Paul_Pitzonka wrote:

that’s a lot of smoke.. if everything else is new, bad right side crank seal would be be my bet....

Good call. I was going all in on carburetion but that could be it. It would work to drain the transmission fluid and then run it to see if the smoke goes away right? Not going to ride it around, just run it on the stand.

|

7/29/2019 4:10 PM
Edited Date/Time: 7/29/2019 4:21 PM

Make sure the needle jet is in there. The main jet threads in to a piece called the needle jet holder and there is a small barrel piece called the needle jet above that. A lot of people take out the needle jet holder and the needle jet falls out without the person knowing it ever was there and it will make the bike runs excessively rich. You will see it here in the exploded view above number 22- https://www.partzilla.com/catalog/yamaha/motorcycle/2002/yz85-yz85p/carburetor

|

7/29/2019 4:31 PM
Edited Date/Time: 7/29/2019 4:33 PM

Paul_Pitzonka wrote:

that’s a lot of smoke.. if everything else is new, bad right side crank seal would be be my bet....

mutti_wilson wrote:

Good call. I was going all in on carburetion but that could be it. It would work to drain the transmission fluid and then run it to see if the smoke goes away right? Not going to ride it around, just run it on the stand.

Yeah that would work but then you’d have a lean condition from pulling air so I can’t recommend trying that... the correct way would be to pressure test it..

|

7/29/2019 10:33 PM

Chad198 wrote:

Make sure the needle jet is in there. The main jet threads in to a piece called the needle jet holder and there is a small barrel piece called the needle jet above that. A lot of people take out the needle jet holder and the needle jet falls out without the person knowing it ever was there and it will make the bike runs excessively rich. You will see it here in the exploded view above number 22- https://www.partzilla.com/catalog/yamaha/motorcycle/2002/yz85-yz85p/carburetor

Are you talking about part 30 on this diagram?

YZ Carb breakdown

|

7/30/2019 8:16 AM

Paul_Pitzonka wrote:

that’s a lot of smoke.. if everything else is new, bad right side crank seal would be be my bet....

I pulled the clutch side cover off and could see the crank bearing through the seal. New seal has been ordered.

I pulled the carb out also and all the parts are where they should be. Thanks for that too.

It'll be up and running in no time. Thanks guys.

|

7/30/2019 8:58 AM

Be sure your float level is set correctly in the carb as well.

Paw Paw

|

7/30/2019 12:59 PM

Paw Paw 271 wrote:

Be sure your float level is set correctly in the carb as well.

Paw Paw

I did and it was right on the money.

|