Bonneville America Forums Forums Technical Forums General Tech Burning oil

For the record I've got an '04 speedy with no AI, no top snorkle and 19" emgo turn-outs. 130/42 3.5 turns

I bought this bike used about 7 months ago with a little over 2000 miles on it. Since then I've done an oil and filter change and I've noticed that about every 1000 miles or so I end up running a quart low on oil.The problem is that I have no idea how this bike was broken in or with what oil.

It's not leaking any thing, so I assume it's oil getting past the rings or past the valve seals. Also worth noting is that the left hand exhaust has more soot build up than the right.

I was wondering if any of you have experienced this and what you've had to do to fix it.

Thanks in advance,

Bob

Is it a big bore engine?

http://www.newspeedmaster.com/html/wiseco_big_bore_kit.html

No, It's the standard 790. Nothing major done to the engine.

I had the exact same experience with mine, I bought it with 3400 miles on it and also burned about a quart per 1000 miles. Like you, I suspected a faulty break in by the DPO. I just checked the oil level regularly until I had the 904 installed (at about 10,500 miles). I'm happy to say that I was able to break it in properly, and hasn't burned a drop of oil in the 13,000 miles since.

Pull the plugs and see if they aren't showing signs of being oil fouled (black oily deposits on the plugs). Also check to see if your airbox isn't full of oil which is an indication of blow by.

Since the bike appeared to be lightly run, the rings and cylinders could be varnished up. I'd take the bike for a good long hard run preferably after an oil change with a lighter non synthetic oil to get the rings to seat. Run for no more than a few hundred miles with the oil then put the synthetic back in. Things should seat properly.

Sounds like it was broken in improperly or not long enough. I would try as Gregger says and put in some nice fresh 30 wt dino oil and run it nice and warm. Gun it almost to the redline and leave it there in the lower gears for about 100 miles (no 5th gear), rev it up and down using engine braking a lot too and that should seat the rings up if that is the case. You can do a search for the "Motoman Break-in Method" and that explains this same process very well.
You could also do a valve check to see if you have a sticky one or the seat is bad.

My bike is running great but my right plug always shows signs of oil fouling and I am using oil where I used to never use any. I've also noticed some oil in the right drain tube from the airbox. Some blowback is possible. D & D suggested running at the bottom line mark on the oil window which was suggested by Triumph. Since doing that my usage has gone down and I've found little or no oil in the tube. BUT, my right plug still shows oil fouling.

I can't think of anything else to do until I get them to check the valve guide seals. The bike is a 904 and has about 18,000 miles on it.

Don't need any more power and the bike runs great. I just don't like the fact it started using oil. This started some time after the 904 install so I think it is not necessary related.

I don't remember, did you coat you jugs or press the Wiseco sleeves in?

Ian, no sleeves, coated like factory. I can only suspect a valve seal problem. Did a compression check and both cylinders were exactly the same. Wouldn't a valve not properly seating allow oil to leak into the cylinder and foul the plug?

The valve may be seating fine and a bad valve seal would still possibly allow oil in. Wouldn't hurt anything except oil fouling the plugs and maybe some carbon build up, also could hinder combustion to a point if enough got in at one time. The latter is doubtful unless the guide is bad too.

To check the valve seals on the cylinder acting up, pull the exhaust header and the carbs. Look in the intake and exhaust ports. If the seal is leaking, you will see oil on and around the valve stem. Typically intake valve seals are the culprit since there is a vacuum in the intake port that will help draw the oil down the stem.

Based on that input, it does sound like a leaking valve seal. The bike is running fine. Besides the fouled right plug, the pipes do seem to have more than normal black sooty buildup. I'll get D&D to check when I can get the bike in for a dyno run.

To fix a bad seal would require a fair amount of work. I may want to wait until I need some other work done.

Verify it is a seal first before doing the job. The seals can be changed without pulling the cylinder head. Not really that big a job. Pull the cams, pressurize the cylinder with compressed air and pop the keepers on the valve spring (one at a time). Change the seal. You will need specialty tools though.

Greg, appreciate the help. That would definitely be taking on more than I would feel comfortable doing. BUT, it does give me the input I need to discuss this with D&D Cycles (my service dealer). I'll get them to check the seals and change, if necessary. At least if that is the problem, waiting until the best time is probably ok.

Bob,

One question for you. When you installed the 904 did you get any head work done such as porting and or larger valves installed? If so there is the possiblity a seal was not installed properly or not put in at all. Hard to tell after the tappet is placed over the spring. Typically these seals do not give problems once installed.

Greg, had no additional head work. This problem started after the engine casing had to be replaced. Not sure if related. I asked D&D if it would have involved anything that could affect the valves or seals. They said no and that a bad valve guide seal is unusual for a bike with my mileage. Still, it is the best conclusion I've heard that fits the symptoms.

The casing change did cause some oil to get into the right side of the airbox. The breather is different on the new casings from my original. Running the oil level in the lower range seems to have helped this. I thought this might be the cause of the right plug fouling but the plug situation has remained the same.