Nico89 Posted July 31 Author Posted July 31 1 minute ago, ajg193 said: Is your firing order correct and is the distributor timed correctly to the camshaft? 1-3-4-2 Rotor aiming at #1 post for TDC compression (easy to get this 360 crank degrees off if you don't check both valves are closed) Yeah firing order is correct, and when I put the new dizzy in, I cranked it until 0⁰ btdc and removed old and fitted new dizzy, both facing cylinder 1 post on cap. I'm new to all this carb and coil stuff so it's taking me a while to do all the tests Quote
ajg193 Posted July 31 Posted July 31 The other one that can catch you out is if the old points signal wire is grounding out somewhere, that will stop you getting spark and make the coil get warm Quote
Bearded Baldy Posted July 31 Posted July 31 Drop the spark plugs in a bucket of water. If they sink, put new ones in it. 5 Quote
Bearded Baldy Posted July 31 Posted July 31 Yes. All spark plugs sink. But if you don't know how old they are, then replacing them is an easy place to start, and cheaper than a new dizzy. Quote
Nico89 Posted July 31 Author Posted July 31 3 minutes ago, Bearded Baldy said: Yes. All spark plugs sink. But if you don't know how old they are, then replacing them is an easy place to start, and cheaper than a new dizzy. Brand new plugs as of yesterday. Have as of 2 minutes ago confirmed strong spark, confirmed compression and i can see fuel squirting in the carb when the throttle is pressed. Just tried starting it for the first time since confirming all 3 at once and doesn't even try to fire. 2 Quote
Nico89 Posted July 31 Author Posted July 31 5 minutes ago, Nico89 said: Brand new plugs as of yesterday. Have as of 2 minutes ago confirmed strong spark, confirmed compression and i can see fuel squirting in the carb when the throttle is pressed. Just tried starting it for the first time since confirming all 3 at once and doesn't even try to fire. I dont know how but after pulling it all apart and reassembling it again multiple times it started and ran fine for a few minutes and then explosively spat out the cylinder #3 spark plug wire twice and then started to idle progressively faster until I shut it down. Now I'm truly lost 1 Quote
ThePog Posted July 31 Posted July 31 This smacks of spark timing issues to me. Or maybe the initial issue caused a timing problem, something jumped, cam belt or some such? Have you gone through the process of static timing it? Quote
ThePog Posted July 31 Posted July 31 Actually if it were me I would check the cam timing first, then the dizzy static timing. 1 Quote
sheepers Posted July 31 Posted July 31 something else you should check is the drive gear on the lay shaft. im assuming the layshaft drives the dizzy, fuel pump and oil pump and probably the oil pump runs off the dizzy drive gear. take the dizzy out and shine a light down the hole while turning the motor to check if the drive gear is ok. 2 Quote
ajg193 Posted July 31 Posted July 31 The drive gear is part of the cam. I've never heard of one failing on a 4K. Drive gear drives the distributor directly. Oil pump is driven by the distributor. Fuel pump is actuated by a lobe on the cam. In fact, nothing really fails on a 4K. There is nothing simpler than a 4K. If the engine was running fine and then started doing dumb shit again it is probably something simple. You say the issue started after doing the exhaust. Maybe you didn't put the intake manifold or gasket back on properly and you've got a stupid vacuum leak somewhere. 3 Quote
JustHarry Posted July 31 Posted July 31 @ajg193 do k series carbs have the fuel kill solenoid? maybe that hasnt been plugged in @Nico89 1 Quote
ajg193 Posted July 31 Posted July 31 13 minutes ago, JustHarry said: @ajg193 do k series carbs have the fuel kill solenoid? maybe that hasnt been plugged in @Nico89 Yep Quote
Nico89 Posted August 2 Author Posted August 2 On 01/08/2026 at 11:17, ajg193 said: The drive gear is part of the cam. I've never heard of one failing on a 4K. Drive gear drives the distributor directly. Oil pump is driven by the distributor. Fuel pump is actuated by a lobe on the cam. In fact, nothing really fails on a 4K. There is nothing simpler than a 4K. If the engine was running fine and then started doing dumb shit again it is probably something simple. You say the issue started after doing the exhaust. Maybe you didn't put the intake manifold or gasket back on properly and you've got a stupid vacuum leak somewhere. What i did to the exhaust was just bending it so it didn't rattle against the driveshaft hoop bolts and sound like the car was going to break in half when under 1200rpm so no manifolds removed I think I either have a massive vacuum leak (it runs better with the choke fully engaged for some reason?) Or my carb has an intermittent fueling problem. First It was acting like it was getting too much fuel, fouling plugs, running real rough etc, and then it turned into what seemed like not getting enough fuel to even fire. When it started for the first time since this issue started, I put a couple ml of fuel down the carb and it fired up but it wouldn't have been enough to keep it running for as long as it did. I'm not the one who assembled or ran in this engine, and I have noticed some less than ideal things such as a lot of red silicon around where the carb mounts to the intake manifold, and the overwhelming smell of fuel even when not running... Quote
smokin'joe Posted August 2 Posted August 2 did this engine set-up ever run decent, or have you been chasing issues ? nothing worse than diagnosing something created by someone elses rough handiwork....... i say rough, because you mention excess silicone sealer around carb, so very possible there has been some to block the vacuum port on base of carb ? or the drilled screw is in the wrong hole and not creating vacuum? Quote
Nico89 Posted August 3 Author Posted August 3 9 hours ago, smokin'joe said: did this engine set-up ever run decent, or have you been chasing issues ? nothing worse than diagnosing something created by someone elses rough handiwork....... i say rough, because you mention excess silicone sealer around carb, so very possible there has been some to block the vacuum port on base of carb ? or the drilled screw is in the wrong hole and not creating vacuum? Yes no issues until this one arose, started up easily and ran fine when warm, doesn't like to idle when cold but seems like a common theme with lumpy cammed 4Ks. It starts great now but the idle still creeps upwards. Haven't really had a chance to investigate yet since I've been busy with other things Quote
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