High rpms sudden oil leak.

I recently purchased a 1983 xj550j. The bike idles fine between 500-1000 until i hit the gas. After i hit the gas it will idle around 3000-4000. Ive been leaving it in first at red lights and releasing some clutch with some break so the idle will goto normal. Just today i noticed oil drips under the bike that had not been there before. I had red lined the bike twice due to the high idle problem. Just wondering if there is a common solution to this problem and how bad it is to now be leaking oil from right above the kickstand. Thanks in advance.

 

The high idle is indicative of an air leak. Check your intakes for cracks. They can be sealed with a black RTV. Permatex makes some. The oil leak could be the tranny cover gasket. Another strong posibility is the oil level sending switch. Will have to remove the exhaust to fix this. But it is mounted under the crankcase with two bolts. Tightening the bolts won't work. The oil is sealed off via an oring. You have to remove the sending switch and replace the oring. First thing to do is determine exactly where the oil is coming from.
You rpost states you have a 1983 550J. The 550J is the 82 Maxim, 550RJ is the Seca, 550K is the 83 Maxim. Not a big difference in trouble shooting this problem but could hinder you in the future.

 

Where exactly are the intakes? How would i check them for an air leak? How did this leak come about all the sudden? There was no leak since monday when i got the bike. I would hate to think i screwed it up myself. On average how much do you think a shop would charge to fix my bike. I could do it myself but the last time i tried to rebuild a yamaha xs400 motor didnt go so well. I.e. had to sell my bike for $100.00. I love this bike and dont want to loose it. Any help you could offer is greatly appreciated. Thanks.

 

Get a spray can of engine de-greaser. A bio-degradable one if you plan on washing the bike in the driveway of near a storm drain.

Warm-up bike.
Spray whole engine to clean it ... apply spray heavy to areas of suspected leak.
15-minutes for spray to "work"
Wash bike. Rinsing area of suspected leak real well.
Run bike on work stand.
Look for leak or drips.
With flashlight ... follow the "trail" of the drip to the leak.
Determine course of action.

Level sensor.
External seals.
Wet cover gaskets.
Oil drain screws.

Whatever external leak you have ... there's enough talent ... right here ... to walking you through de-leaking your ride.

Don't bring it to the Dealer until "We all" determine that would be the best solution for you.

Unless ... you have the bucks and want to get the ride fixed and back-in-action fast.

Your call.

 

Just a reminder to the helpful people out there that the 550 is chain driven so the front sprocket shaft seal is around that area.

But, As Rick already stated, a good gegrase is required to pinpoint the leak.

 

Purchased the degreaser. Im going to try and pinpoint the leak tomorrow morning. Im still not too sure where the intakes are located but hopefully the degreaser will also reveal this airleak source as well. Thanks again for all your help.

 

These leaks your looking for at the"intake" are going to be revealed as cracks in the black rubber boots that run between the airbox (the place where the airfilter lives under the seat) and the carb. also check the boots between the carb and the engine, these are morelikely too be cracked then the other boots.

 

I had a similar problem when I first got my 82 xj750. After synking the carbs all is well. Check and see if there is a carb clinic in you area or another xj'er in you area that can give you a hand. I am a little far away. You may try turning down the idle scew under the carbs just a touch as well. Something may be causing it to hang up.

 

Okay. Did the degreaser trick and noticed bubbles around the boots that sit between the carbs and the motor. How do i go about synching the carbs myself? I took a picture to post online but my camera quality is horrible. I am going to pick up another digital camera soon so i can take pics for better reference. The degreaser also pointed out my oil leak problem as well. It is located directly under the left side motor cover that says YICS on it. By the way what does YICS stand for? Under the cover there is what looks like a large allen key shaped groove it is leaking from directly under there. Thanks again.

 

Bubbles indicate your intake boots are leaking. You will need to seal them up with RTV. Pull them, clean them up, fix any cracks, reinstall with new/good used gaskets and RTV.
If you look up at the top of the XJ Chat page, you should find a few Stickys up there that should give you a good idea on how to make your own sync tubes and YICS tool.
Your oil leak sounds like a bad main shaft seal but I'm guessing here. I'm not terribly familiar with the 550 but it is similar to the 650/750 in a general sense. To replace that half-moon seal would involve draining the oil, destroying the old seal, snaking the new one in (if it is a metal backed plug, your sunk, gotta split the case) with a thin film of RTV and buttoning it all back up.
Best of luck and look up the stickies, you'll find a wealth of information there.

 

Ok , bubbles indicate a leak for sure. You have to seal the leak before you can sync. So get some Permatex ultra black. It is a high temp RTV that will go on with your finger tips. You can smear it into the cracks and seal the leaks. The oil galley plug that is leaking has an oring on it that most likely has gone bad. Remove the plug and take the oring to an autoparts shop and get a replacement.

 

Sounds like your refering to the main oil gallery plug as BlueMax said.
Robert is refering to the crankshaft end seal, which you could only see if you took the YICS cover off the engine and removed the pick up coil plate.
If this seal was leaking you would find oil inside the YICS cover.


YICS = Yamaha Induction Control System

Here's a picture of the right side main oil gallery plug circled in red.

 

Nick, you are so cool! Thanks for the pic and the clarification between mine and Robert's post.

 

Those red-circled plugs are vulnerable to being road-rashed if the bike doesn't have case-protecting crash-bars.

If this is where you are leaking from because the lower edge of the plug is scraped-up ... there might be enough damage to the case to make stopping the leak an adventure.

Wrap the threads on the plug with at least three layers of Teflon thread sealing tape.

 

My gallery plugs have o-rings. I missunderstood "directly under", my goof. I figured it to mean directly under the cover. Sounded like it was leaking underneath the cover itself. Simple fix for sure. What would we do without you Nick? You'll save us, one and all! Case Savers are an excellent investment, one of the first things to get for a new owner.