G2 rocker oil feed updated , advice please

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

Post by Richard Hyatt »

Definitely clear jets,
We've tried oil can on the oil entry hole of the rocker cover and oil will come out of the jets then no problem , but won't pump up there.

The hole in the head that brings oil up we've poked and the wire goes right down to below the cylinder base level , I assume to the pump outlet
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clanger9
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Re: G2 rocker oil feed updated , advice please

Post by clanger9 »

What sort of state is the rest of the engine in? If the timing side bush is severely worn (for example), you're not going to get much oil up to the head...
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Richard Hyatt
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Re: G2 rocker oil feed updated , advice please

Post by Richard Hyatt »

As far as we know ok , there's no rumbling or rattling.
We haven't actually stripped the engine since pur haxe , but it looks as though someone has reassembled it for sure.
I agree if the timing side is worn it could bleed away any pressure there.
But still , when run for 5 minutes or so, others loads of oil splashing about up there.
I've looked at the video on YouTube of a G2 oil in the rockers and there didn't seem to be much leakage from the rocker spindles , hence pushing the oil out of the jets
Richard Hyatt
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Re: G2 rocker oil feed 042044

Post by Richard Hyatt »

Hi again
The ongoing saga continues.
We've cleared out all oilway in the head and rockers. Replaced the pump guide pin which wasn't too bad.
Whilst we had the oil tank off , we took the gearbox out and removed the pump screwed end plug , O ring fine.
Finally tried to remove the blanking button at the opposite end 042044 to check the O ring , but after removal of the screw 042046 , we tried to prod the button out from the opposite end (where the screwed end plug is) .
But the blanking button would not move at all outwards and we didn't want to hit it to much.
I'm concerned that the little screw 042046 has broken it's end off in the button.
Should the little screw have a tapered end to go into a slot in the button please.?
Would anyone have a picture please of this screw and a picture of the button?
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clanger9
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Re: G2 rocker oil feed updated , advice please

Post by clanger9 »

I'm afraid I don't have a picture. 042046 is a small bolt with a ~2mm peg on the end. The plug 042044 a a solid barrel with two grooves in it - one for the o-ring and one for the bolt to screw into. If it's not leaking, I guess there's no need to remove it.

Has someone drilled holes in the rocker box where they shouldn't? There is no need for there to be much oil up there...
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Richard Hyatt
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Re: G2 rocker oil feed updated , advice please

Post by Richard Hyatt »

Thank you for response
Holes in rocker box ?
Only the 1 incoming hole(That gets upset when the gasket is reversed)
The 2 little jets
And a 3rd jet over the exhaust valve area

We did find the worm gear on the pump had wear on the teeth , the individual teeth were very knife edged, probably half of the majority of the thickness of each tooth,
Clearly worn.

It had scavenged, just not delivered enough pressure to push up to the top of the rocker box jets

I'm pretty sure that the 2mm pip has broken off the end of the bolt , but I cannot shift the plug and O ring

Should this blanking plug just push out after removal of the locating bolt please?
cbranni
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Re: G2 rocker oil feed updated , advice please

Post by cbranni »

Yes it should just tap out, if you are lucky

Just a thought is the metering valve in the rocker box in place, it's the one I have highlighted in purple, if this is missing then most of the oil will end up on the base of the head and not where it's suppose to be.

Image


As I said, it's just a thought. Colin
only dead fish go with the flow
Richard Hyatt
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Re: G2 rocker oil feed updated , advice please

Post by Richard Hyatt »

Hi Colin,
Thank you for this,
Yes the little jet is there in place , just above the exhaust valve area.
We've bitten the bullet and got the pump out now , the teeth are worn and very sharp , so the drive will be reduced for sure.
We're just trying to get the blank out but the little bolt has the end broken off making it difficult to push the blank out !
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Ozmadman
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Re: G2 rocker oil feed updated , advice please

Post by Ozmadman »

Why not just leave it where it is then? it is just a blanking plug and does nothing else so if is not leaking then there is no problem with it.
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Richard Hyatt
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Re: G2 rocker oil feed updated , advice please

Post by Richard Hyatt »

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
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