Johnson 70hp VRO Oil air lock

[Revhob]

Hi there
Hope someone can give me some advice again on this one. I got an air lock in my VRO system as it ran dry. I then added oil to it again and it didn't feed through at all. While out at that time, the engine died and we managed to get back in on very low and slow revs. I managed to get the oil flowing again, but it seems some damage has been done. It idles and rev fine in neutral, reverses fine, but when engaged in forward it only goes slow or cuts out. On the flush muffs at home, when engaged in forward it revs and spins fine in forwards. Took it out on the water again with a back up engine and a knocking noise has started. Does anyone have any advice, it seems strange it works fine on the muffs but not in the water. Any help gratefully received.

 

[joetheis]

Sounds like you did damage to the motor by not running 2 smoke oil through it, (the knock). Bad things are happen, don't run it anymore!!!!
Also I'm gonna think you broke the V.O.R. pump by running dry??
First, find/fix the K-nock, then figure out you oil feed problem, (the oil side of the V.O.R. isn't re-build able). There is a site I found to test the pump oil feed
The motor won't run under load, (prop in the water) which is why it'll idle and run with muffs
But, as you were doing that, it was running without lube in the bottom end.
Funny, no alarms beeps or lights when oil tank was low???
I hate to be the bearer of bad news.
Keep us posted
Joe
Take any advice I give with a can of beer or 2!

 

[Revhob]

Ok will look into it. Is there anyway of testing to find out what the knocking noise is in the bottom end with out paying out too much money?

 

[Faztbullet]

First pull the heads and inspect cylinder walls then progress from there.....

 

[joetheis]

You can try pulling a spark plug, bring the piston to close to T.D.C., (top dead center), use a wooden dowel, push in, see if there is anything funny?? (note spark plug color. Should be from brown to oily black, not light tan of clean-that means lean-no oil.
Compare the 3 cyl.
No matter what you find you gotta dive into it. take it apart.
LOOK close at your roller bearings,on crank, rod bearings, piston pin, cyl. wall. Blue or worn is B.A.D.!
All that is protected by oil.
Good thing the season is winding down, sadly looks like you got a nice winter project!
Joe
A bot is a hole in the water where you toss$$