Next: Oil Pressure woes...

Rule of thumb for oil pressure needed in a car engine is 10#psi for every 1000 rpms. That's up to a certain pressure/rpm. As long as you can keep the bearings floating you should not have a problem in most cases. If your under 10#'s at idle I would begin to worry a little of the bearings slightly touching the crank and wearing the babbit off or what ever coating is used on them.

It doesn't know if it's a car or motorcycle or what ever engine. I look at that rule of thumb for all street driven machines.

 

That's pretty typical for the 1st gen VF's but it does sound like you may be a bit lower at idle than you should be.

Re: oil pan gaskets. I got a new one with my head gasket kit but that's more than you want to spend for just a o-ring. The gasket itself was just a regular o-ring. My guess is it was in the neighborhood of 2-2.5mm section, maybe 3mm (measure the pan to get a better idea). Diameter was probably on the order of 15-18cm. I checked and I don't think you're going to have any luck finding an o-ring with that section with a big enough diameter. If you're old gasket isn't leaking just reuse it. If it is leaking a little bit of gasket sealer should do the trick.

-Jake

 

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Did you change the oil filter ?? what weight oil are you using ?? ANY fuel in the oil from leaky carb needles will lower oil pressure. Pick up screen on pump could be dirty.

 

I was running 10w40 Valvoline Bike oil. Last week, when I noticed the pressure start dropping, I changed it, new Carquest oil filter (wix) and refilled with Sell Rotella T 15w40, which is now approved for Cycle use, and has been used for several years by some bike mechanics.

I tore apart the spare oil pump that I have, and it is far from perfect, but not trashed either. I can tell that there was some metal through it (this is the engine that had the top end wiped out) but the sides of the rotors are in pretty good condition. The tips of the inner rotor are "pitted" from metal having gone through the pump. I'm making it sound worse than it is. I think I need to get the pan off, and look at the pickup and o-rings, etc. on the running engine, and decide what way I'm going from here. If all looks good, I need to find some main and rod bearings.

 

@GreyVF, I would be happy with 5 psi at idle, it doesn't make any substantial noise the way it is now, it's just getting progressively worse.

I would like to get more than a few hundres miles out of this bike each season! :lol: Last year, I was just getting it sorted out by this time, and this year I've put 3-400 miles on it. I seem to be getting better with it! I'm just glad I have the Ninja 250 to fall back on to get my riding in!

 

It is not uncommon for oil pumps of that vintage to have serious wear issues.....inspect it and cross your fingers.

 

Better keep the Ninja, you'll need it. I had an oil pressure drop in my goat several years back. I went thru all the other pieces parts such as lines, gauge etc. In the back of my mind I knew what the problem was. Had to pull motor to get to oil pump. Damned enough the check ball was held open .005" by a piece of valve spring tip that broke off. This thing was only about a 1/64th triangle piece of metal .005 thick. Because of the lower pressure of 5#s at idle it wore a couple of rod and one main bearing down to copper. You mentioned the extra oil pump you have is pitted from metal from worn cam. I tried to explain in another topic sometime ago that you need to clean the motor if that happens and was jumped on by other people here that you don't have to, the bike will run fine. Yes it may for a while. They said that's why you have an oil filter. The filter only filters oil to the crank and cams NOT the pump or trans. That pump pitting is one thing that happens in the long run. Do you know if your current motor has had bad cams/rockers before? I would not trust that 5#s at idle is ok. It's to low to fully support the crank. I would pull the oil pump and inspect it and the O-rings for screen. I pulled the pan on my 750 this year because of leaking pan gasket. I also pulled the pump screen and it was partially plugged with normal wear filings and sealant goobers. The motor had never been apart before. I think your running on borrowed time.

 

Thanks Grey for the well noted post.

 

Yea....Grey is right.

With these motors you need proper lubrication for it to last...even for a little while.

You spent so much time getting it together....don't trash the engine with the low oil pressure.

Sorry to hear about your troubles. I can certainly sympathize with anyone having issues with their VF500.

 

You mean like: "Fudge this VF! I'm gonna move on to something else!" ????

 

Oh, I'm not riding it anymore. The last ride it will take is the 1.8 miles to get it back here to the shop, until I tear it down to find out what's going on with it.

At this point, I'm comtemplating buying a pump off ebay, in hopes that it's in better condition that what I have. I'm not doing anything else until I get the pan off it and see what's really going on in there.

 

The thing is, I have very little money in this, so I can go for a while, without becoming totally insane over it.

 

Keep 'em flying!

 

Are you referring to the parts of the engine leaving the block?

 

Fixed :tongue:

 

^^^ Nice one!! LOL

 

Hey! where are the valve springs??? Have they flown out of the picture??? :laugh:

 

LOL.....yea. Or they're in the pan in little bits.