A seemingly unusual issue with Zong Storm 250GS
 

My 06 Storm is sucking oil into the airbox..
At first I thought that the air filter was just really stopped up and was creating a vacuum. The problem with that is, I removed the filter completely and it still pulled up into the airbox. The bike now has a ton of power compared to before now that I have the filter removed, so I think it was bad. I will need to replace that of course, but either way, there should not be a ton of oil in my airbox. About 3-4oz of it.. Has anyone else ever experienced this issue? If so, what was the problem and how did you fix it?

How is the oil level in the crankcase?

This is the unusual part. The levels are perfect. So it's not overflowing at all. It's like the case is becoming pressurized somehow.

The case is becoming pressurized from combustion gasses blowing past the rings.

Do a compression check to confirm. It is likely low. Make sure the valves are not too tight (staying open) and recheck. If still low add a little oil to the cylinder and recheck. If it is the rings, and I'm pretty sure that's what it is, the compression should momentartily increase.

If this confirms my diagnosis your engine needs a top end rebuild.

I had the same bike and it needed a top end at less than 2,000 miles.

To remove the head and cylinder you have to remove the engine first. Noit a fun job, but do-able.

I fear it's blowby past the rings as well, especially if it does it with the air filter removed as well... Time for a leakdown test!

The interim band-aid would be to re-route the breather hose out of the airbox. On all of my bikes, the breather hose routes behind the motor and points at the ground.

Wouldn't this cause the case to squeeze out oil when pressurized potentially getting onto my tire?

As far as doing a compression test what are you referring to?

Yup.

If you do that realize that it won't fix anything and will be temporary.

I'd fashion a filter/catch basin for the oil as it could lubricate your tire and cause an accident.

I don't recommend it as the bike now runs and is rebuildable if you choose to. If you run it and it seizes it may damage the lower end and make it unrebuildable.

Compression check:

http://www.dansmc.com/compression_test.htm

Thanks for the link!

I would consider the fix if this were a daily driver for me. It's too cold to be out on the bike currently, so being out of commission right now isn't going to be a big deal. I'd rather take care of the motor and avoid ruining it more.

I have access to a compression gauge and I will be checking that tomorrow night. The poor compression alone could explain the engine running terribly. I will more than likely rebuild the whole motor within a month or so. I will need to tear it all down to find the true problem. Once I've done that, I will try to get a write up on here. Hopefully it won't be too much of a task. Warm weather will help.

Agreed. Hence my band-aid reference.

Hopefully rebuild parts will be cheap as chips on eBay, which would allow you to buy a new piston, cylinder, rings and gaskets as a package.

I think you will be the first to attempt a rebuild on one of these. I hear you on the cold. I stood on the courthouse steps yesterday waiting for a house to come up for auction. 9am to 3pm. Windy and 25 degrees.

Maybe the first of many if I can manage to do a good write up on it. I see that you're in Auburn, I'm actually in North GA in Hall County.



Hopefully the parts won't be too expensive. I've got a pretty dependable dealer down in Miami that I've been sourcing parts from. I don't have much into this bike, so I've got some room to work. I will have to tear it all down and see what the real issue is then we'll see if its worth operation. :)

The PIA I ran into with mine is that you can't remove the upper end of the engine without removing it from the frame :x .

Not the end of the world but that's where I said 'screw it' and sold it to a guy who wanted to fix it up and sell it on. I paid $150 for it, put about $150 in parts into it, and sold it for $200, IIRC so mostly all I lost was time and dignity :oops: .

I figured that would be the case. There isnt really too much holding it in the frame right? I just need to take off the chain, carb, exhaust, and motor mounts. And maybe the shifter linkage?

That's it. I just didn't want to put the effort in at that point anymore. Mostly I was aggravated I bought a non-running bike with no compression and then spent $ on it's ignition system only to then find out it needed a top end too.

It's a good looking and seemingly comfortable bike, and should have Zong like relaibility but on this forum people have not had good experiances with them. Mostly ignition and piston problems.