AD-21 injection pump

[honza]

Would anyone know what is the correct model number of injection pump for AD21? I have, on the boat, Simms P5069 - manual does not specify pump model. AD2 Manual says Simms P4717/1, which agrees with a photo within. Parameters for both motors are practically identical, with the exemption of max. RPM (2200/2400), HP (20/22) and torque (5.3/6.5). Any ideas about replacement injection pumps? Thank you.
Jan

[dkirsop]

I think it would be hard, if not impossible, to find a replacement pump that could readily fit this engine. The injection pump gear drive also drives the water pump impellers, which is one complication, and the gear cover on the on the engine is a complex casting that mates with the injection pump. In my opinion there is no room on this side of the engine to accommodate adapter plates and shafting. Do you need to replace the pump or simply have it re-furbished?

I recently had all seals and interior gaskets replaced on my pump. The technician reported that the internal components had virtually no wear but that all the seals were shot. I had located a seal kit from Star Diesel for the pump and took the pump into the specialist shop for the overhaul and calibration. Previously it leaked oil like a sieve, now it is tight and running well. Performance was never an issue. If this is an option I will pass on the part number for the seal kit.

[dkirsop]

The part no. for my Injection Pump is P5069. Here is a link to the thread I posted when I had to pull the pump and get it serviced. viewtopic.php?f=28&t=10760

[honza]

Thanks Dkirsop for the replies. Now, at least, I can be sure, that I have the right pump model installed. If I could find a replacement, I would probably replace the pump, but it looks more likely, that I will be sending it out for a rebuild. So, it could be helpful to have the part number for the reseal kit.

The motor takes 20-60 sec. of cranking before it starts on a warm day and there is no air in the system and no big black cloud of smoke after starting, so the verdict is internal problem (leak) in the IP, and that may not be as easy to repair as yours. There is an oil leak from the back of the pump also.

[dkirsop]

Here is the info on the injection pump seal kit. As mentioned in the thread I sent this has to be ordered through a US distributor. I used Accurate Diesel who forwarded the kit to me in a timely manner and at reasonable cost. I can't remember what the cost was but it seemed reasonable at the time.

Rebuild Kit.jpg

Your problems in regards to starting may relate to more than just the pump performance. Low compression and worn injectors could also be problematic. Low compression is easy to check if you still have the hand crank for the engine. You should not be able to turn over the engine by hand without using the compression release. If you hear air escaping when applying effort on the compression stroke (the key word being effort) then you are due for a valve job. Worn injectors also will cause poor starting.

It is unlikely that the rings will be worn given the lack of smoke.

[honza]

I thought I had posted a reply, but it is not here.

Thanks for the info and advice. When the weather gets bad an I find a while to work on the boat, the pump and al the injectors are going to go to a diesel doctor in Caribou Maine for a checkup and overhaul. He says, that he works on Simms' regularly and does not need the kit.

The way of thinking regarding compression was, that any case of low compression - due to valves or to rings - would cause heavy black smoke after long cranking. The idea comes from a local guy, who reportedly, has a lot of experience with old tractors. While cranking, the accumulated diesel causes the compression to go up and makes the engine to fire - but it has to burn out right afterwards. I'll try to hand crank some time soon anyway.