Oil Pump Delete

[boby]

I've looked through a number of posts and haven't found the answer yet, although it's probably been answered numerous times. How often do the oil pumps in 787s go out? Is it something to worry about and premix or would you just clean the oil system and run good oil through it. I was thinking about moving it over to premix to prevent the worry of a seizure. Thanks!

 

[kustomkarl]

This question has been asked about 1,000,000 times...if you run the injector you will use less oil and it will cost you less in the long run. The injector is a variable rate injector, as it injects oil at different rates as it is needed in the rpm range. The oil pump will very seldom, if ever, go bad. If the pump cable breaks it pumps oil at full rate so it won't lean out the mix a seize up. I suggest you stick with the injector and you have to replace fouled spark plugs either, that get fouled from too much oil at the 40:1 ratio as it is required to be pre-mixed.

Karl

 

[boby]

Thanks Karl. I pulled it apart today and it looks like I don't have much of a choice. The person I bought it from added the block off plate and got rid of the pump. But that's just a long list of bad ideas that I didn't notice until after I bought it. Like only boring out one cylinder so it had two different sized pistons in it....

 

[kustomkarl]

Yeks!...that's never a good idea. If you have more questions remember to give us a shout.

Karl

 

[6KJR]

Looks like you better check it over really good.

Some people don't like pump delete. People like myself love the pump delete and my machine works fine. I don't mind a little extra oil. It does have to be done a certain way on engines with a rotary valve tho.

 

[boby]

Oh I have. It's been stripped down, bored out and built up. So far the problems found were:

1) One cylinder bored, other not, giving two different size and weight pistons
2) Engine oil pump bypassed - Thanks for not telling me
3) RAVE valve in the bored over cylinder not relieved (Cause of the engine failure)
4) One carb not having a gasket between it and the head, and the bottom bolt hole stripped out.

And I want to say something else but I can't remember it now. If I think of anymore, I'll let you guys know.

 

[reelimpatient]

KustomKarl, so there is a specific way to delete and bypass the oil injector?
My 96 GTX 787 has the block off plate, and I would like to make sure its setup correctly. I know there is one oil line going to somewhere towards the bottom of the engine, but What should I look for?

thanks !

 

[boby]

There are two oil lines that still need to run to the engine, the one that comes from the top of the oil tank and runs by the exhaust is down below the two cylinders. I believe this one lubricates the gears for the rotary valve. The other one is one of the two that came originally out of the bottom of the oil tank. The one that went to the oil pump should be plugged, the other one goes underneath the carbs and lubricates the rotary valve itself if I'm not mistaken.

 

[reelimpatient]

Karl, I just bought a 99 GTX RFI with 72 hours on it and still injected. Would you recommend I leave it like that or convert to premix for the long haul ?

He's ran the quicksilver PWC oil in it as long as he had it. Is that okay?

thanks !!!

 

[seadooya]

This question has been asked about 1,000,000 times...if you run the injector you will use less oil and it will cost you less in the long run.

Karl

Not if the oil pump freezes up.

You probably spend an extra 2.50 in oil, for every 10gal of gas, going premix.

 

[Dr Honda]

Not if the oil pump freezes up.

When's the last time you heard of a Mikuni oil pump freezing, or failing if it was not deprived of oil?

Honestly, I've never heard of one failing on it's own. There are always other issues like clogged lines, or running the engine out of oil.


The big advantage of running the oil injection is much less smoke at idle.

Now... if you owned a Yamaha... I would be all for removing the pump.

Just my 2 cents... take it for what it's worth.