breakerless ignition / ballast resistor

Correction - that rotor should not have a 'T' on the end... but it still appears to have been getting pretty hot.   Looks cooked where the coil wire comes in and as I said earlier the contacts inside the cap appear to have melted metal smeared on them.

Anyone know the part numbers for that cap / rotor?   

That link in my first post was my actual dizzy.   Did a search before-hand but didn't come up with anything on the setup in mine (think it's a Prestolite)... mostly Pertronix.

Talked to Richard over at SKIDIM this morning, he assured me that it was okay for the ballast resistor to be bypassed.   He also said that the screw down caps do not need a gasket.

Described my problem to him and he seemed to think my base timing was off a little or possibly the air gap on the ignition module. I'll check that ASAP and post back.


Tom

fixed link

nuttyskier2002 wrote: It may be the glare of the pic but that rotor looks really old. I'd change it and the cap and plugs and maybe even the wires. Then check your timing as advised above. After running it for several hours, pull the cap and check it for anything abnormal looking.

The problem I mentioned in the first post of this thread is a rough idle condition.   When I go to gear it tends to stumble and I have to pump the throttle to keep it going.   

Here are the items I've checked so far:


checked timing - okay   (as far as I can tell, not sure of the exact idle rpm.   it's 10 degrees BTC whatever rpm it's at (more below))


air gap on the ignition module seemed too close.   actually looks like it may have been rubbing.   loosened the adjustment screw and set at 0.008. (skidim recomendation)


sprayed carb cleaner around the intake / carb base looking for vac leaks, nothing.


checked idle / air - only out 1/2 turn.   opened another 1/2 turn (both sides) and the idle smoothed out significantly.   still seems like it's idling rough.   

plugs / wires look relatively new, pulled #1 plug and it looked okay and was gapped around 0.038.   tach doesn't work right, when I rev it to what I'm thinking is around 3k rpms it moves up to maybe 1k rpms.   wondering if it's related... any ideas?

79nautique wrote: doesn't sound like the idle mixture screws are adjusted correctly get a vacuum gauge and set the screws so that it reads max vacuum on the gauge, meaning highest it will go, not highest marking on the gauge. Seems like it really lean have you lloked that the accel pump's operation? and made sure it is squirting gas the complete stroke?

These sound like great suggestions -

Where should the vac gauge be connected?   

Not exactly sure how to check what you're asking on the acc pump... pop the breather, work the throttle, and verify the carb is squirting all the way?

Looks like a new carb... has some sort of gold colored coating on it.   I did find a vac outlet just under the mouth of the carb that was sealed off.    Made me wonder if it was an automotive carb.

You should also be setting the idle mixture screws with the engine warm and idling in gear. So this obviously needs to be done on the water. Numerous off idle stumbles have been fixed by setting the idle mixture just as 79 states but in gear and idling. You may have to readjust the idle RPM and then I would recheck the timing lastly just to make sure everything is spot on.

That is a marine carb. I don't recall right off hand for sure about the functionality of the port that is taped off, but it's supposed to be there and it's supposed to be open. Take that tape off. Maybe somebody else can chime in on what it's for.

The vacuum port that you want to hook up the vacuum gage to is the PCV port at the back of the carb. The PCV valve is plumbed in from the port side valve cover to the back side of the carb adapter. Photo 12 is a good shot of the PCV hose.

I dont believe that the fitting thats taped off is a true vaccuum port. Ive only seen it used to attach the 1/4" overflow line coming from the fuel pump. If not in use, Id keep it taped up (mine has a rubber cap), but it probably doesnt matter much.

It doesnt look like a new carb to me- it looks like the original marine unit that someone painted or recoated with that orangy-gold stuff. I cant tell from the pics so I dont know if your carb has one, but only a newer Holley (within the last few years) will have a vaccum port on it- the one on my '90 doesnt have one. The port would be on the baseplate of the carb on the starboard side, aft of the choke housing. The vaccuum port that Eddie's talking about is on the rear of the 1" intake spacer.

Update - I still haven't put a vac gauge on it but I dinked with the mix some more and changed the plugs and now she's idling nicely.   I had ruled out the plugs due to the one I pulled looking good and the fact that it had new wires.   But I had a couple with fuel on them and a couple more that looked really bad.   

Thanks for the help verifying the carb was indeed for marine application and what to do with the vac port.


Tom