TOPIC:

In April, I bought a Vulcan 750, so the cop bike wasn't getting ridden much. I had a bad starter clutch and basically the bike sat waiting for parts. I had decided to sell it and wanted to do a valve lash job first as well. So the bike didn't get ridden or started for about two months. It was under a carport but a couple of sideways rain storms got it pretty wet. Anyway, once I finished the starter clutch and valve lash job, and had it all back together I started it up and it ran like crap. So I added some seafoam to the gas and fired it up and took it for a ride. At first it ran crappy throughout the rpms but after a couple miles it started smoothing out and then ran fine except for idle, which was messy and too high. I don't think I got much over 60 mph when I test drove it.

So, I pulled the carbs and cleaned them out and pulled the air/fuel mix screws and cleaned pretty thoroughly and reassembled and installed the carbs. Now it idled fine. I went ahead and pulled the timing cover and cleaned and lubed the advancer. Took it for a test ride and it ran very good except that it started cutting out at around 4000 rpms, kind of like it was starving for fuel. I tried it with the fuel cap open and no difference. So, I pulled the tank off, and opened the petcock to see how it was draining gas. It came out fine, but I pulled the petcock and checked the screen and it was clean, no rust or anything blocking anywhere. I also replaced the inline fuel filter at this time. Put everything back together and test rode and same thing, cutting and missing out at around 4K rpm.

I had replaced the wires back several months ago, but used the old caps, so I decided to buy new ones from Z1 and got them today, so I put them on at lunch and decided to ride the bike back to work for a test. Now it misses badly even at idle and all throughout the rpm range. I turned around and parked it at home and rode the other bike.

I figured I'd pick up new wire on the way back home just in case the new caps don't like the old (new) wire. One of the old caps, on plug #1 was cracked in half. I figured I'd probably found the problem but wouldn't have dreamed it would run worse.

I figured that if the plug caps didn't make a difference, I'd pull the carbs off again and check the diaphrams to make sure they were in good shape. I feel like I'm going all over the place here but thought I'd run it past all you folks and see what ideas pop up. Thanks!

Check the spark plugs and check the resistance on the coils.

I forgot to mention that I put new plugs in at the same time I did the valve lash job. B8ES, or BE8S or something like that...gapped at .030

I'll test the coils resistance. I'll have to find instructions on that...

17k-20k ohms between the two spark plug wires on each coil.

2-3 ohms between the two small wires on each coil.

what is seafoam? are you running fresh pure gasoline yet?

Seafoam you can get at auto parts houses, a few oz's added to tank will clean some garbage out of the carbs as it runs through.

Steell, I did check for 12v at the coils with ignition on and it is good. I didn't test the coils yet though... Couldn't find my auto ranging meter. But..
I just ordered intake manifolds (carb holders) from Z1. WiredGeorge is going to bust my chops on this one as he told me to replace these on the bike back in December. I thought I heard a hissing sound while the bike was idling today and got the carb spray and sure enough I got bad carb holders, at least on #3 for sure. So, I wait for my carb holders to arrive, and for WG to tell me he told me so...

Dang, it would be nice if this fixes the problem...

Just pull the bowls off the carbs and soak your jets and clean up your inlet ceits under the floats. install an inline filter & ride it.

if your diaphrams on the slides are cracked or torn, remember superglue and an extra set of hands will make a temp repair until you get new ones at z1-enterprizes.