Not the owner the bike! Ha Ha. 2000 400ex 2 weeks old 2 tanks of gas. The bike has been smoking since day one. Small amounts of white smoke when thotling. Help?

 

This has been covered many times before. Run a heavier weight oil. The 400EX runs hot, due to 2 reasons, it's air cooled, and it's jetted lean from the box.... It breaks the oil down very quickly.

Mine did the same thing, I switched to 20w50 and the smoke went away. Now I run 15w50 Mobil 1 for several reasons. If you want more info, just ask.....

If the heavier weight oil doesn't fix the problem, take it back to the dealer for warranty service.

If you're new here, you probably don't know about the throttle mis-adjustment problem of the 2000 400EX either. Check the adjustment of the throttle cable. Most 2000 EX's are adjusted so that they only get about 60~80% throttle. Fix that and you get some extra free HP. Made a big difference on my bike....

If you need anymore info on anything mentioned here, just e-mail me.

 

Sounds like your engine wasnt broken in properly and rings and cylinder are glazed resulting in blow by.I doubt you have valve guide leakage on such new engine.Have cylinder honed(unglazed)and break it in right.Heavier weight oil will only be bandaid fix.remember if oil is getting in past rings you will also be loseing compression(lost performance).Fix it right.just my advice.

 

I think I agree with Gabe on this one. I properly broke in my 400ex. A few weekends ago, I changed my oil (10w-40). Now, its usually bit cooler up here until about this time of year, and this was one of the first days I rode it when it was about 80-85 degrees out. Anyway, after riding really hard for an hour or so, I saw a puff of blue everytime I decelerated. took a quick look at the dipstick - the oil looked/felt like water. I dropped it the next day to put in 20w-50, the stuff looked like junk - way broke down. Just my experience - I mean, looking at that oil (10w-40), I can't see how it couldn't slip by even the tightest built engines.

Then again, with only 2 tanks of gas through it - it shouldn't have been run hard enough to cause the aforementioned problem, unless proper break-in isn't being followed.

 

Thanks..

Having grown up in an automotive bodyshop around all sorts of cars, and working in a machine shop under my uncle for a while, I have built several 2 and 4 stroke engines and am quite aware of the proper break-in process.

I ran 20w50 as a little experiment for 1 oil change before my warranty ran out. I had suspected that the oil was breaking down. When I put the 20w50 in, the smoke went away. Several hard, hot rides later it began to smoke on decel again. I proceeded to drain the oil, it was nasty and broken down. I then replaced it with synthetic Mobil 1 - 15w50. The smoke went away again. The change interval is much longer under the Mobil 1. The oil stays cleaner much longer as well.

Also everyone has reported the same problem, not a continuous smoke (rings), or a cold start smoke (guides/seals), or even smoke on acceleration, but smoke on decel only after being ridden hard....

All this seems to point to the oil breaking down, not an engine problem...

 

Wassuuuuuup, Gabe!
Just wondered if the synthetic gave you any slippage problems yet vs. sae oil? This will open up a can of worms, but what are you thoughts on that one?

 

Nope, no slippage problems, I have had it in the dunes with synthetic also, very hard on the clutch.... You may want to stay away from oils that say "energy conserving" supposedly they have friction modifiers that may cause problems (never tried it myself). You won't find 20w50 or 15w50 in energy conserving though, usually they are the 5w30's. Which makes a person think the friction modifier line is a bunch of crap. Looks like it has more to do with weight than anything to me (haven't really researched it though)...

 

Duplicate, servers been having trouble all day.....