White smoke under decelleration

[TT120]

I just bought a new 06 kat 750. I have about 5500 miles on it so far and it has been blowing a little white smoke when I'm using the engine to slow me down going down a hill. It doesn't seem to happen when I'm just coming to a stop and using the engine compression a little in each gear. Only seem to occur when I'm using compression braking for a little while like going down a hill.

Bike is new 06 750, stock except for a Yosh rs-3 slip on. Nothing done to the jets.

Any ideas?

[arsenic]

If you'll done nothing to the jets, they come lean from the factory, I'd say your running lean, go a 1/4 out on the A/F screws.

[TT120]

Thanks Arsenic. Please excuse my noobieness, but, are the A/F screws accessible without having to remove the plastics?

I'm assuming A/F means Air/Fuel mix screws and that they would be on the carbs somewhere....

[arsenic]

no they aren't accessible without removing the plastcs. They aren't even accessible withoput removing the carbs. The A/F screws have EPA brass caps placed over them, you'll have to drill they caps, put a self tapping screw in there and yank the caps off. Then next time you need to mess with them, you can use this:

http://www.motionpro.com/motorcycle/tools/pilot_screw_adjusting_tool/

and you won't have to pull the carbs.

[MikeM]

Have you by chance laid the bike down recently?

[TT120]

Thanks Arsenic, I was afraid of that. Methinks that is a little beyond my capabilities. I tried to remove the carbs from my CB750 four once many years ago and was never able to get them back on. Guess I'll just buy a jet kit and have a shop do it for me.

MikeM: nope, have not laid the bike down. It's still as pretty as when I rolled it off the showroom floor.

[reconstyle]

White smoke is usually water isn't it?

Did the problem start right when you put the exhaust on?

[TT120]

White smoke is usually water isn't it?

Did the problem start right when you put the exhaust on?

Dunno, I put the Yosh on only a couple weeks after I bought it. It was brought to my attention last week by another rider. Couldn't be water since it's air cooled.

[The CyberPoet]

The how-to is covered on my website here:
Installing a JetKit on a 98-06 GSXF Katana motorcycle.

Although it talks you through installing a jetkit, it will also show you where the pilot screws (sometimes called air-fuel A/F screws) are, where the caps are, how to get them off and how to adjust them. Click on any of the pics for a larger version.



As for the white smoke, if your area uses alcohol-added fuels, it could very well be running too lean and causing this.

Cheers,
=-= The CyberPoet

[TT120]

Yeah, we have alcohol in our fuel out here in Cali. Will it hurt anything if I leave it that way?

[The CyberPoet]

Yeah, we have alcohol in our fuel out here in Cali. Will it hurt anything if I leave it that way?

Depends on how lean the bike is jetted. California models are usually closer to "extremely lean" than standard 49-state models to compensate for CARB requirements.
The only ways to know for sure is either to have the exhaust gases measured on an exhaust-analyzer equipped Dyno, or wait until something fails (exhaust valve typically, which unfortunately means the whole engine most of the time).

Cheers,
=-= The CyberPoet