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Old 04-03-2020, 08:28 AM   #8
oceancrosser
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City: Somerville
Vessel Name: Kristine
Vessel Model: DeFever 53 POC
Join Date: Mar 2014
Posts: 50
Quote:
Originally Posted by EngNate View Post
Are you closing the priming pump after use by pushing in and turning clockwise till it seats? With it closed it should not leak air into the system even if the plunger seal is bad. Anyhow, these pumps are available aftermarket and I got one on ebay for about $30 a while back. There are two places on the injection pump where air can get in if seals fail - The main drive seal and the fuel rack lever shaft seal (throttle lever shaft). If the throttle shaft seal is bad you should be able to detect at least trace leakage there. Bad main shaft seal will also leak when stopped, and this is directed through a tube to the front lower right of the block, when facing the engine. By pinching off the return line and keeping constant pressure on the priming pump for a couple minutes you should be able to confirm either of these. The throttle shaft housing should come off with the injection pump in place. The main seal means remove and tear down. I have worked around a bad main seal by installing an electric lift pump and placing a can under the tube. It collected about 1oz or so per hr running. This got me by for quite a while before I got the pump overhauled.

Yes, I am turning and closing the knob fully.


This is going to take more knowledge and expertise than I have in my wheelhouse to make this remove and repair injection pump.



A couple of years ago, I had my starboard engine's injection pump overhauled and there seemed to be some "local" knowledge on replacing back.


I will follow you troubleshooting advice and try to nail this issue down.


Also, I do have a new primer pump on the way to our marina.


Truly, thank you for everyone's help.


"learning has occurred"


Rusty
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