View single post by Gary Martin JH 15371

Posted: 05-07-2005 08:23 pm

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Gary Martin JH 15371

Joined:	03-12-2005
Location:	Portland, OR
Posts:	98
Status:	Offline

OK, I have many things to check now. I don't think I overly tightened the inlet valve. I did use the thicker Aluminum seal as this is what carbs had before. By the way these are not the burned carbs, but a used set off an "un-burnt" JH. The float level was set to spec listed in rebuild kit. The carb kit did come with one choke gasket, the internal one. But not the one that seals choke to side of carb. That gasket is still good and I can re-use. I was not sure if there were other gaskets or seals internal to choke, evidently just the two gaskets.

I have been reading your articles in JHPS monthly mag. I have been working to rebuild the vacuum switch. I used a counter sink and made a new beveled seat. The rounded seal was scared, and I have tried to make it seal against the seat using a fine valve lapping compound. I think the main problem is the diaphram. It is old and dried out. It causes the internal parts to lean over to one side when actuated. It does not open/close in a centered position, but tilts over to side. So for now I decided to not use and capped of the bypass valves. My vacuum switch did have a gasket on lower part (you mentioned you had never seen one there).

Carb Sync was done after it was warmed up. I did have a question about the Temp Compensators. Jim at Delta told me that when cold, they should just barly close. And to make sure they open when warmed up. They do open when warm. The tension on the bi-metal spring seems the same on both carbs.

My distributer is rebuilt. The advance springs and weights move freely and are cleaned and lubed. New points, condensor, rotor, cap, wires, plugs. The Vac advance diaphram does work, but if you check with hand vac pump it will not hold vacuum for more than a few seconds, so this may have an internal leak. I will disconnect for now and see if this improves things. The internal wires are in good shape, but are a bit stiff as you explain. I installed a new power lead and this is particularly stiff.

I have not checked manifold vaccum yet. I will do so shortly and advance the timing to 12^tdc. I will also check the plugs to see how they are doing.

Almost forgot. The throttle shaft on rear carb is loose a bit. This could also be a problem. Can these be re-bushed ?

And last, I have another set of 175 Stromberg's off a early 70's Volvo. They are very similar. Both carbs have a choke which seems good. But there is one difference, the Volvo carbs have an extra linkage that operates a valve internal to the carb body. Has anyone used Volvo carbs on a JH ?