Used a whole different top end from the Valve cover,Valve assembly,cylinder,piston,rings,wrist pin and new gaskets. No part of the original top end was used when i swapped them out.

Im certain it has nothing to do with the top end after I swapped everything out with the same results while following the manual to the letter from torque pounds to tightening sequence.

Im leaning towards a bad oil pressure regulator or a clogged oil labyrinth/passage.

 

Fresh oil and filter change afterwards? Or have you checked for too much oil or oil possibly contaminated with gas? I've seen smoking happen both ways with either too much oil in the crank case or thinned down oil from gas contamination slipping by the rings causing smoking.Plus is the air filter clean and the air box dry,no oil back up?

 

Engines with ball/roller bearing cranks tend not to have high oil pressure so I doubt if a stuck pressure relief valve would cause the symptoms. Check the breathing system out first, and as OPT wrote, the wrong oil level can cause problems, is the dipstick the right one for a Vinson?

 

Fresh oil and filter change afterwards? Yes

have you checked for too much oil or oil possibly contaminated with gas? Oil level is dead on and not contaminated

Plus is the air filter clean and the air box dry,no oil back up? Air filter is clean and air box is dry

Check the breathing system out first. I went through the whole breather system and all hoses are cleared out and so is the breather box it uses.

is the dipstick the right one for a Vinson? There is no dipstick there is a window on the right side of the crankcase and with oil change and filter it uses 2.4 qts (Per Manual)

Ive used fresh oil and a new filter after both rebuilds, I ripped into the right side of the motor last night and cleaned all of the passages i could find and tested/ceaned the oil pressure regulator. It seemed a little gummed up but not to bad. I have to go do brakes on a 30' KW dump truck this morning and i'm going to grab some kerosene and flush the motor.

 

Ran kerosene through it doing a flush twice. Made no difference.

im going to rip back into the right side and check out the oil pump.

Hauling sugar beets for another week so wont have time until next week.

 

OK back to this headache.

Picked up a oil pressure test kit with the suzuki fitting.

Book says 18-25 PSI @ 3K RPM. Im holding steady 60 PSI (3K RPM) and it peaked out at 70 PSI.

I looked at the oil flow diagram and am thinking the oil pressure regulator is stuck closed. Which is allowing oil to exceed the normal pressure and allowing way to much oil to get pumped into the motor.

Diagram attached. Seem like the right direction or diagnosis?

 

My Arctic Cat 500 (same motor) has a stuck oil pressure relief valve, over 100 psi when oil is cold, it goes down when oil gets hot, but still higher than normal. It uses absolutely no oil in 500 mile changes. Don't think that is the problem. Here is a picture of the oil pressure gauge. I've driven it over 3,000 miles with the high oil pressure, kinda surprised the gauge hasn't failed. Something is going on, oil should not be dumping on the exhaust valve. Never watched mine run with valve cover off, but I always figured that the oil just runs back to the oil pan. High oil pressure isn't the problem. Here's a picture of my op gauge as the motor is only up to 98F. 75 PSI at 5,000 rpm. BTW, if you put a tachometer on, you'll be surprised, they will really rev.

 

I appreciate the post hydrex. Most of my research is still pointing at the pressure relief. Part comes in next week. Ill post the outcome good or bad.

 

Is this pressure relief valve like a lot of models have (bolt with plunger or ball bearing and spring) or something entirely different. On the oil pressure flow chart looks like it is a different type set up.Calls it a pressure regulator. Looks like some kind of separate module. Just curious..

 

it is a spring loaded apparatus. I tried cleaning it last time i had the cover off. Seemed fine but it only has to catch or hang up a little to not do its job.

It screws into the main "artery" for oil movement.