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750 Oil control jets.

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royhall:
Just had a horror moment reading another thread where it says "oil jets, what oil jets". Just like that engine builder, I didn't know about the oil jets either.

When I stripped the engines top end I found a problem with one of the cam carriers. The oil drilling to just one of the journals was blocked causing scoring, the other journal was okay. I replaced the carrier with a good used one, but as I didn't know the oil jets existed I didn't clean them (oops). As I say, only one side of the carrier was damaged, the other good. This probably means the oil jet was not blocked and oil was flowing, or they would both be damaged. I found the blockage in the carrier itself.

Is there an easy way to run the engine and verify oil flow, without oil blasting everywhere. Thought I may take the tank off and remove the tappet caps one at a time and see what happens. Is this a good plan, or am I stripping it again.

Cheers all.

Bryanj:
You can run the engine with all the caps off, yes oil will spray out in small quantities but not a vast amount. back when did many re builds where the owners had done there own and not kept the oilways scupulously clean blocking a jet, also had many carriers bushed with bronze. If it was me i would take it back out, remove the cam and carriers and take the jets out to give them a thourough clean also blowing air through the oilways to ensure no gasket debris or sealant blackage

Mike on a bike:
I don't know if you were referring to my thread but here are some pics that may help. A. is with the restrictor removed and B. is with the restrictor in place. It has an O ring around it and looks like it is part of the engine case so it is very easily missed. Just take a pointy nosed plier and pull it out. Definitely sounds like the problem you have. Unfortunately you will have to strip the top of the motor down. I had to do it twice with new gaskets each time.  :( One of mine was 75% blocked.

royhall:
Thanks for that Mike. Did not realise these were removable jets when I was doing the engine (first Honda 4 for me). However, I did blast carb cleaner and compressed air through them to clean up any old oil etc. Shame they didn't blow out of the seats at the time. So am hoping I will be okay. Going to try to do a running check through the tappet covers this afternoon. Fingers crossed. :-[

MarkCR750:

--- Quote from: royhall on May 04, 2015, 11:11:08 AM ---Thanks for that Mike. Did not realise these were removable jets when I was doing the engine (first Honda 4 for me). However, I did blast carb cleaner and compressed air through them to clean up any old oil etc. Shame they didn't blow out of the seats at the time. So am hoping I will be okay. Going to try to do a running check through the tappet covers this afternoon. Fingers crossed. :-[

--- End quote ---
Roy, how did the running check go?, I'm interested because I didn't rebuild the engine that I am currently using in my CR (I have another engine that I am boring out and rebuilding), the one that's in there seems to run ok but had been sat for years so I'm asking for trouble really by not stripping it, I did clean the strainer gauze but that was about it.

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