G2 rocker oil feed updated , advice please

Information relating to the Matchless G2 or AJS Model 14 250cc Lightweight
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clanger9
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Re: G2 rocker oil feed updated , advice please

Post by clanger9 »

Probably a good thing that you did check the oil pump. When the teeth are worn, they can strip (with very messy results).
I was surprised at just how thin the teeth were on mine when I rebuilt it:
http://www.jampot.com/forum/viewtopic.p ... 24#p186831
1989 Moto Morini Dart 350
1993 Ducati 750SS
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Ozmadman
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Re: G2 rocker oil feed updated , advice please

Post by Ozmadman »

Richard Hyatt wrote:We were tempted , but we weren't sure if the loss of oil pressure to the rocker jets was caused by the oil bleeding past the O ring in the blanking button.
It seemed daft not to have it out and replace the O ring whilst we were in that far.
It was then we discovered the end of the screw broken off (I assume in the groove) making it difficult to extract the blank.
We just want to cover everything that could have prevented the oil getting to the rockers
And
Having covered all the other bits and still not got oil up there , were forced to go deeper , discovering the screw on the pump plunger very thin teeth
Makes sense :beer:
Paul
1960 Model 8
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Richard Hyatt
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Re: G2 rocker oil feed updated , advice please

Post by Richard Hyatt »

Just an update for all of you who have given advice and ideas.

Found the blockage ! Eureka.

Engine out of the frame and oil pump out already. Blew air into oil hole on crankcase mouth and out popped a huge , really huge blob of silicone from the P.O.
See what happens when we spin the crank when all reassembled.
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clanger9
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Re: G2 rocker oil feed updated , advice please

Post by clanger9 »

Wow! Well done for persevering. :beer:
A great example of why silicone sealant should never be allowed anywhere near an engine...
1989 Moto Morini Dart 350
1993 Ducati 750SS
Richard Hyatt
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Re: G2 rocker oil feed updated , advice please

Post by Richard Hyatt »

so - we have a new pump , button / peg bolt and O ring and new guide pin . SAE 50

any hints and tips on installing the new pump - obviously prime it and grease the teeth and engage/twist or rotate the crank to mesh the gears properly and then tease the guide pin in whilst looking in the guide pin hole to ensure the slot is in the right place.

our new pump has an extra hole in the feed part of it(the flat slot is identical) - the scavenge side is identical. I got it from RUSSELLS who has been mega helpful , so hopefully it will be fine.
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clanger9
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Re: G2 rocker oil feed updated , advice please

Post by clanger9 »

Yes, the one I got from Russells also has an extra hole (don't know why):
http://www.jampot.com/forum/viewtopic.p ... t=oil+pump

It should go together easy enough. As you say, make extra-sure the groove in the oil pump is exactly lined up before screwing the pin home. Of course, put the pin in the right way round (fat end to the plunger).
1989 Moto Morini Dart 350
1993 Ducati 750SS
Richard Hyatt
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Re: G2 rocker oil feed updated , advice please

Post by Richard Hyatt »

Hi again to all the helpful contributors during my rocker oil problem.
Just a thank you , it's all sorted and running and nice and oily up there , despite a worrying delay in appearing , lo and behold out it squirted . Phew.
cbranni
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Re: G2 rocker oil feed updated , advice please

Post by cbranni »

That is good news Richard.
only dead fish go with the flow
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ajscomboman
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Re: G2 rocker oil feed updated , advice please

Post by ajscomboman »

clanger9 wrote:Wow! Well done for persevering. :beer:
A great example of why silicone sealant should never be allowed anywhere near an engine...
Can't agree with that, maybe monkeys with out much idea of how much to use shouldn't be allowed anywhere near an engine whilst using silicone is probably more accurate. The modern Triumphs and Honda's advise using silicone sealant on their rocker cover gaskets etc. However they don't advise how much! :headbang:
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