Are XR 400's smokey?

[jteale123]

Hi all,

I recently bought a xr 400 to do up and go round Iceland on. Got it just about ready for the MOT now, but was just wondering if they are ment to be smokey? When the bike is idling there is no smoke, but under hard acceleration or a rev of the throttle in neutral it will give out some blue smoke. Is this normal?

Cheers for you help guys

[XRDAVE]

I think the simple answer to this is no. I'd take a look at the rings.

[jteale123]

Damn that is what i was thinking, but the comperssion is very good (enough to try and break my ankle) so was hoping it was normal.

The smoke seems to nearly stop when the bike is up to running temp. Hopefully it will get me round iceland and then i can strip it down when i get back.

It is a 1998 model so a nice strip down should do it good

[Redbus]

Before stripping down to check the rings check the valve seals and valve guides for wear.

[walesxr]

Before you start stripping, make sure that you have not overfilled the oil tank, when checking engine oil I always leave the bikes ticking over for about five minutes upright (not on the side stand) otherwise you will end up putting too much oil in and smoking.

If the oil level is correct, then you will need to fit new rings and valve guide oil seals, I have never come across valve guide wear on this model. If you feel competent at preforming a top end engine rebuild then I generally go for the next size bigger piston rings and file them down to meet the minimum required gap (you must make sure that the ends meet perfectly, beware that the second ring is softer than the top ring).

But as your engine only appears to be smoking lightly, I would be tempted to just use it and keep a eye on the engine oil.

[jteale123]

Cheers mate.

i am planning on doing a oil change any way as i have only had the bike a week so will make sure its at the right level and then see how she looks.