Smoking?

[mokwepa]

Hi guys

Some days my 13 Evo 300 seems to smoke more (white smoke out the pipe). I noticed it after a 4km ride back from a training spot. When I killed the engine, white smoke was still coming out the pipe.

Anyway, did some training today and its still smoking a bit. Obviously im now conscious of it and took for it. Its not allot but ive never noticed it before.

Im running bellray h1r @ 66:1 (ratio that everyone runs here). Ive checked the plug and its dry and a fraction darker than perfect.

Anything to worry about or am I just being paranoid?

[laser1]

Thats most likely unburnt oil in your mid box. No big deal. Probably a result of your super conservative oil ratio.

[0007]

Ya it's unburned oil that's coating the inside of the exhaust

When you get the pipe up to high temp such as hill climbing it basically cooks off the oil

As this is a symptom rather than a cause, cleaning it will not stop it from happening again

I think most trials bikes do this anyway, it's because we don't get the exhaust temp up often enough, you may be able to make it better but I doubt you can stop it completely

I think you're running a bit too much oil

[mokwepa]

Ok, hope its just that.

Next thing, while fussing over the bike getting all worried, I noticed that the oil is a greyish colour, still reddish but a grey red if you understand, not milky or sign of coolant. The coolant level is still fine. Im running Dex6 Atf and I have been ridding quite a lot and fairly hard (to my novice standard). Last oil change was about 2-3 months ago. Ive been told by the local boys that all use this Dex 6, that it should last about 6months. I do ride more often than them, is my oil just old and due for a change or could this be linked to the smoking? I do hink the smoking is oil in the pipe though, that makes sense.

Thanks for the replies.

[feetupfun]

if you have a leaking crank seal on the drive end of the crankshaft, you can test for it by measuring the quantity of oil that comes out when you change the oil. The discolouring of the oil with use you describe sounds pretty normal to me. If the oil is doing its job, it holds the fine wear particles from the clutch plates, bearings and gears in suspension and these fine particles change the appearance of the oil. Also if you are looking at the oil soon after riding the bike, the oil will be full of microscopic air bubbles, which also change the appearance of the oil. As far as change frequency goes, base it on the number of times you have to refuel the bike, or number of riding sessions, rather than in elapsed time. However if you don't ride much, the 6 months oil change is a good idea because oil absorbs water from the atmosphere whether you ride the bike or not. If you ride in water, check for contamination of the oil after each ride and change it if there is any water contamination.

Trying to answer your question about a possible link between the condition of the gearbox oil and a smoking exhaust - no, old oil will not leak more easily through the crank seal than new oil.

Maybe you are worried that crankcase fumes are leaking past the crank seal and discolouring the gearbox oil? If this is a problem you could test for it by extending the gearbox breather tube and putting the end of it in some water with the motor running and see if bubbles come out.

Another thing you can do to put your mind at rest is to take note of when the pipe smokes. As has been mentioned earlier, oil condenses inside the exhaust when you ride as if you are competing in a trial, and it revolatises when the exhaust gets hot (when you ride up a long hill, or ride along a road at speed). You should see more smoke when the pipe is hot, compared with when you are puttering around gently. It is good to give the bike a hard run and heat things up, because apart from cleaning out the exhaust, the piston rings may otherwise become gummed into their grooves.

[lineaway]

• As much as you ride, change it once a month. Does everyone run H1R? It really does not burn real clean. 80;1 would help.