No oil to rockers model 8

[Janet]

Paul, the fault is mine. I was answering the question in Iain's original post and said the gearbox has to come out because I thought that was how you get to the oil pump.

[Ozmadman]

Paul, the fault is mine. I was answering the question in Iain's original post and said the gearbox has to come out because I thought that was how you get to the oil pump.

No worries Janet, just re-read it from the beginning, you are right about the pump and answered exactly what he originally asked but it skewed off course a bit to just the pin replacement which of course is a lot simpler but I still had the gearbox removal issue in my head and answered accordingly

Paul

[irsooty2]

Is this the guide screw in question?

[cbranni]

It is and there should have been a pin sitting inside, with the smaller dia in first. On the right hand side of the pump there should a be a steel bung with an o ring fitted to it held in by a screw......is that there?

Colin

[irsooty2]

Hi Colin,
Screw came from hole marked:- "screw to locate pump plunger" in Paul's picture, "engine casing details pdf",
Nothing else there as far as I can see? There is another to the right with a collar of some kind?
Sorry if I'm not making much sense!

[Ozmadman]

Hi Colin,
Screw came from hole marked:- "screw to locate pump plunger" in Paul's picture, "engine casing details pdf",
Nothing else there as far as I can see? There is another to the right with a collar of some kind?
Sorry if I'm not making much sense!

That is the right screw and it looks like to me that the pin is actually the smooth bit sticking out of the screw!! it can be held there by hydraulics making you think it is part of the screw. If that smooth bit is solid then it is the pin, grip it with a bit of cloth and give it a few twists and tugs to see if you can pull it out.. Remember to insert the new pin THIN END FIRST(thin end goes into the screw)

(colins quote)

On the right hand side of the pump there should a be a steel bung with an o ring fitted to it held in by a screw......is that there?

This is on the RH side of the picture where i have put end cap and screw to locate end cap/plug... If that is there there is no need to remove it as it just seals up the end of the tunnel where the oil pump shaft fits into

Paul

[irsooty2]

Spot on Paul!
A few twists and out it came, it doesn't seem too bad but will replace now I have the chance!!
I'll order Monday, pop it back together and see, if nothing I will take the head off and investigate.
Thanks everyone for all the help, it's made this job simple and enjoyable!
To be continued........

One quick question rather than start a new thread.....
I need a new carb spacer, there is an option of 28mm or 30 mm, carb body and engine are 28mm but my knackered spacer seems to be 30mm? What should I replace with?
Thanks
Iain.

[Ozmadman]

The correct carb is 389/42 1 inch and an 1/8 bore just check that this is what you have but I can't see that it will make much difference as long as it is not smaller than the carb bore. Just another check, have you got a valve lifter on the cylinder head as if it has a 250 head on it ( no valve lifter) then the inlet may be fractionally smaller as the carb is a smaller bore. The pin looks like it has a shallow groove in it and it won't take much for it to reduce the flow as it isn't exactly a brilliant design in the first place

[clanger9]

I've been reading this thread with interest. Is the oil feed arrangement on a Model 8 different to late-Model 14s?
The reason I ask is that the oil feed holes above the pushrods are blanked off on my bike - but oil still seems to get there.



How does the oil feed to the rockers work?

[cbranni]

That head looks like a 250 head from 63/ 64 when AMC did away with inlet valve stem oil screw and oil flow to tappets and push rods, must have relied on oil mist for lubrication, I think the oil pump output was increased too.

Colin