XS1100 oil pressure high

[MotoPoesy]

I've got a solid riddle.

1980 XS1100 Special, new to me and just fully renovated and will start right up, but it blows its oil out first minute of running, four times so far. Once, blew hose off oil cooler, and three times blew out the soft O-ring on oil filter casing.

Breather hose and chamber clear and clean, with no oil in filter box.
Oil distribution line to valves and the two attaching banjo bolts clean and clear.
Check valve in the oil filter bolt clean and functional.
Valve lash spot on for all valves.
Timing correct, cams and gears correct.
Oil level confirmed correct each time.
Bike has never been on its side.

Suspected blowby on some cylinder, compression check cold read 150, 150, 140, but hardly anything on no. 4

So, I tear it down and remove head. Valves clean and seating fine; head gasket clean, no corrosion in any cylinders, pistons clean and traveling smooth and silent cranked by hand.

Would rather not, but wondering if I need to pull cylinders to search further, inspect rings condition, pull them to insert in cylinders to check gaps for spec.

Anyone ever had a bike that just pissed itself like this? I'm kind of out of ideas.

Perplexed in Pittsburgh

[Radioguylogs]

[If you removed the cams] I would first place the head upside down, with the spark plugs installed, and put some kerosene or mineral spirits in the valve domes. Make sure #4 valves are not leaking worse than the other cylinders. This test is only to be sure the valves are the cause for low compression in #4 cylinder.

If the #4 valves are OK, you might as well pull the jugs. It's not much effort after you already have the head off. If the valves were good, you should anticipate to find something wrong with the rings or the piston in #4. It would explain the excessive oil pressure and the low compression.

It should be interesting to hear what you find. Good luck.

[Tonyxs11]

you've gone this far so worth pulling the cylinders off and checking the rings.

[Ranger_xs1100]

Hi MotoPoesy, If you do find a problem with the cylinder such as being scored or whatever, and since you're in the neighborhood, I have cylinders here. Good luck and let us know what you find. Bob

[kboehringer]

Yamaha XS1100 XJ1100 Piston Ring Set STD 71.5mm -Set of 4 - Repro
eBay item number:303234375714


Just an FYI. I've used these cheapo aftermarket rings in ALL of my XS11's with great luck.
If you end up pulling the cylinders IN MY OPINION these are a great choice for CHEAP! and worked great in all of my XS11's.

Also this seller offers a complete repop gasket kit for the XS1100 for something like $80 (head gasket, base gasket & o-rings, side covers gaskets, etc.)


KURT

[MotoPoesy]

Actually, I did happen to buy those rings, had them "saved" while jugs were coming off. Glad to have a testimonial.

[MotoPoesy]

So, I might have found the problem, though I won't know for certain till all is back together and ready for start-up again.

Pulled the oil pump, spent far too much of my life removing/ravishing the three torx bolts that hold the pump gear and pressure relief valve and spring beneath their plate. And found the valve seized-up. Hope this is resolved, we'll see soon.

[Ranger_xs1100]

This 20 year old post may be of interest to you when reassembling:

10-29-2002, 10:34 PM

oldfart XSive Join Date: Aug 2002 Location: North Bay,Ontario,Canada Posts: 84

oil pressure did you have the oil pump apart?if so,when it was reassembled the oil pressure relief valve can be installed back into the pump backwards and still fit!been there, done that!!!the sympton of this IS to have the oil filter "O" ring blow out.

[MotoPoesy]

That is worth noting. I replaced my piston as i found it, and I'd suspect it has never been inspected, judging by the screws, unmarred, versus what I had to do to them in damage to get them removed. Bolts still serviceable fortunately, but i used penetrant, torch, center punch, vice, impact driver, and rinse and repeat the cycle until the dremel and BF screwdriver were required. They are no joke.

[MotoPoesy]

Problem resolved, engine holds its oil at last. Cleaning the piston and bore of old, dried oil permitted it to function again, no more worries--in this one account at least. Thanks all.