So no significant change with the sorted pcv valve. It still runs better, and doesn't try to stall when I blip the gas, if the choke is pulled out a bit. Further examination to commence today.
Hi its brand new, I replaced it with a good quality points one as I couldn't test the one that came with it which was electronic. I have just stripped and cleaned the pcv valve and found that it had been assembled incorrectly in the past. Hopefully I can test it today.
I hate to suggest this, but I’ll stick my neck out, sounds like you may have a couple of plug wires swapped. Double check your firing order 1-3-4-2 counterclockwise.
Thanks Steve, that was one of my first thoughts but it is testing fine with no looseness or visible cracks and there is no change when spraying carb cleaner, easy start or gas at the join.
After you finish following Scott's expert experience advice, and if you still have a "miss", I'm just offering "my individual experience" just as an FYI. "my miss" ended up being from a crack in the intake manifold at the flange area, only offered as another place to check out for "intake leaks", especially since you've added the "changing of carbs info" now.
Look inside the distributor cap for carbon streaking. Are the contacts in the cap brass or aluminum? They should be brass. Plug wires should be copper-core and non-resistant. Spark plugs should be copper-core and non-resistant.
Both checked again and fine. I also had the misfire when the old solex was fitted and this prompted me to buy the carter to try to isolate the problem.
Hi, no the idle is not high I set it to spec during the process. I will check the metering rod and the float height just incase. The fact that it seems better with a bit of choke would suggest a leak or carb issue. I am a little worried that the valve timing might be out by agear tooth or two, is this possible and can I check it without removing the engines front cover?
What is your idle RPM? If it is high you may not notice a change in tempo when performing a vacuum leak test.
Did you set the metering rod with the Carter Gauge? Check for a gap between the top inside of the Metering Rod eye and the pin it is supposed to rest on when the rod is bottomed out in the jet.
Just a thought but if the throttle shaft bore was oversize and introducing air I would expect the engine to respond when I sprayed carb cleaner over the carb. I get no such response suggesting that there is no leak but I will have a look.
Hi, thanks for the reply. I have used the vacuum gauge as described before and set idle and mixture accordingly. If anything the misfire becomes more evident.
15º is way too early. Find the highest vacuum reading with the distributor then back the rpm off 100. Lock it down. Adjust the steel idle stop screw to again get the best vacuum reading then adjust the idle mixture screw to 650 to 700 rpm. If this is unsuccessful, then you may be experiencing a problem I've found in a few of the JMP carbs. The throttle shafts and the bores are, from the factory, not to spec. Both should mic out at .3125".
