Baja 250cc Dirt ZS167FMM 2004

[oviking99]

Originally Posted by Weldangrind

I was looking at your bike pics again, and I noticed this (in the white circle). What is it?

Thank you sir! My camera found my air leak. Thats a vacuum port on the intake manifold. Maybe the source of the backfires. It will get plugged thanks to your catching it. I lowered the camera to take the shot. Almost impossible to see.

[oviking99]

When I started this thread I made a mistake by calling it 2004 ZS167FMM. Actually it is a 2007 Bajamotorsports X250, __167FMM. The frame plate says X-motos XB-31, as recracer pointed out. The engine is stamped 167FMM. I have seen references to X-motos XB-31 by Zongshen. My point is I am unsure who the engine mfr is. I 'assumed' it was Zongshen. The engine has no mfr letters before the engine number. I see that there are several variants of this bike, Gio, etc. Does anyone know offhand who the engine mfr is, and what 'clone' the bike and engine is of? Thanks for the help.

[oviking99]

Researched a few threads. CG125 based. Close to a CRF230. Thanks Weld, saw your post in another thread.
Still curious to the real MFR.

[Weldangrind]

Originally Posted by oviking99

Thank you sir! My camera found my air leak. Thats a vacuum port on the intake manifold. Maybe the source of the backfires. It will get plugged thanks to your catching it. I lowered the camera to take the shot. Almost impossible to see.

I was hoping that would be helpful to you.

[oviking99]

Weld, that was absolutely the problem. It always helps to have another set of eyes. It runs incredible. Starts instantly cold with choke. I was beginning to think my carburetor rebuild was somehow at fault. Thanks again. It has incredible power. Unfortunately I'm getting blue smoke, hard to believe it needs rings with the power I'm getting. Interestingly it doesn't smoke all the time. I'm wondering if someone 'rebuilt' the top end and didn't install the rings correctly. Either way its off with her head. For now I'll keep a close eye on the oil, and ride it till I complete the Vento 200gy-2.

[recracer]

http://www.chinariders.net/showthrea...hlight=heather . This was Heathers thread . She could give you the answer . if she still checks in

[oviking99]

Thanks recracer!

[oviking99]

Ebay.com has a 69.00 cylinder kit with free shipping. I'm gonna wait until I receive the clutch springs from Amazon for the Vento before I tear down the top end. Too many projects in various stages. One day the 2004 Renegade.

[Weldangrind]

I'm inclined to think the oil burning is a valve stem seal problem, since the motor has decent power. Still, off with her head.

[oviking99]

Originally Posted by Weldangrind

I'm inclined to think the oil burning is a valve stem seal problem, since the motor has decent power. Still, off with her head.

I agree Weld. No knocking or pinging, under low rpm hard acceleration, just incredible low end torque. I am very impressed. If it is rings, it's the best engine I have ever run that needed them. It will pull me up a steep incline from second gear, standing start at 1/2 throttle. Anymore throttle, and I can feel the rear tire knobs deforming, causing it to 'squirrel' on asphalt. I weigh 175. I take it, it is a complete engine pull to remove the head?
Thanks Weld.

[oviking99]

When I rebuilt the carb, there was a scaley grit that was difficult to remove. I used my dremel and a small cloth rouge polishing wheel to remove it from the body innards. I have to believe, thats the reason it runs so well. I have heard pro's and cons of doing so, but in this case, polishing the carb innards certainly increased air flow and performance, over what it was with the scaley deposits. FYI I am using the stock airbox and filter, light oil coat, on the foam filter.

[Weldangrind]

Originally Posted by oviking99

I agree Weld. No knocking or pinging, under low rpm hard acceleration, just incredible low end torque. I am very impressed. If it is rings, it's the best engine I have ever run that needed them. It will pull me up a steep incline from second gear, standing start at 1/2 throttle. Anymore throttle, and I can feel the rear tire knobs deforming, causing it to 'squirrel' on asphalt. I weigh 175. I take it, it is a complete engine pull to remove the head?
Thanks Weld.

Glad to hear that it's such a good performer!

No, I don't think you'll need to remove the engine to remove the head, but i could be wrong. It depends upon how much clearance you have to the backbone. I'd remove the motor, simply because I'd want to examine the motor mount holes and also to apply Loctite to each mounting bolt upon reinstallation.

It's also an opportunity to clean everything well and check for leaks and damage.

[bogieboy]

I know on my db07 i needed to pull the engine just to adjust the valves, couldnt get the cover off, so im thinking it may be the same for him, although at first glance there does appear to be more room above the engine than my frame...

[oviking99]

Thanks guys. Weld I agree with your advice on removing the motor to check the mounts. I see some hairline fractures where it was welded poorly. I've had my problems on bikes at the welds before. Vibration can wreak havoc on poor welding, especially on a non counter balanced thumper.

[oviking99]

Actually, after research, I guess there is a counterbalance shaft?