Bearcat isn't running well

[Kelly]

I'm not sure what's going on. At first I thought it was bad gas, then fouled plugs but now after cleaning the plugs and getting new fuel with Stabil ethenol treatment it's still running bad after 20 minutes of running around the lake. It runs fine for a while (20 mins), even sounds great at WOT, then it sputters and acts like it's starving for fuel. The bulb isn't "full" in the fuel line but then again it isn't when it runs fine.
I installed a new fuel pump last year and it's no longer "making oil" but it's definitely not running like it was. I tweaked the carbs by ear but that's about it.

Thoughts?

[jhomeist]

Fuel supply issues: 1) Have the carbs been cleaned recently? 2) I replaced my fuel pump last year. This spring after a 45 min cruise at 4500 rpm it wouldn't idle. The fuel filter bulb was mostly empty, as previous, but it seemed like the pump wasn't pumping gas into it like before. I replaced the filter and moved it from upstream to downstream of the pump (I'm told they push gas better than suck gas). Haven't had idle problems since and the bulb stays completely full. Perhaps the filter was clogged, but I think moving it downstream of the pump made the difference.

Spark: I also had inconsistent performance last summer (part of the reason for a new pump). After warm up, the rpm would drop in half, and then very somewhat, but it would otherwise seem fine. After cooling it would run fine again until warm. I switched to electronic ignition and that solved the problem. I suspect it was the condenser going bad. Weird things happen when condensers start to fail. It's a cheap easy swap to try. That's my bet if the fuel system is clean

[jhomeist]

As I think about it more, my coil was also bad, there was oil leaking from it at the output post. A bad coil will also cause problems that sometimes don't show until hot. It's another relatively cheap swap, but these types of issues are why I went ahead and put on electronic ignition.

[Helmar]

I'm not sure what's going on. At first I thought it was bad gas, then fouled plugs but now after cleaning the plugs and getting new fuel with Stabil ethenol treatment it's still running bad after 20 minutes of running around the lake. It runs fine for a while (20 mins), even sounds great at WOT, then it sputters and acts like it's starving for fuel. The bulb isn't "full" in the fuel line but then again it isn't when it runs fine.
I installed a new fuel pump last year and it's no longer "making oil" but it's definitely not running like it was. I tweaked the carbs by ear but that's about it.

Thoughts?

I kind of remember mine doing that at one time. You could run her up and she seemed to be fine than start crapping out. It kept changing on me, some times at a idle it would act funny.
Pulled the carbs and use my torch tip cleaner with the tips cut off to get into every little nook and cranny but still the same thing, but not all the time...
It really had me going.

So, I am not Real sure how I cured the problem as I did several things but I still had my point (I am ok with running points) but I took John Nelsons advice and that was I went and got a coil and matching condenser for a 1968 Ford 390cu engine, put the condenser and used some duct tape to strap on the coil and all we well.
Then I rebuilt the coil mount and also found she started better with that coil.

I kept looking at idle and even one time running with Cindy at the helm at the spark by pulling a plug wire off (used my special spark plug pulling tool, lots of rubber insulation) and was looking to see if the spark was blue and not red. I seen it with not very blue so called John and went over things with him about it.

I think mine was a combination of junk build up and the condenser to be honest.
At one time after towing all the way up from Oregon she would not run at high speeds, not even up on plane and after putting her back on the trailer, I pulled the carb and found a Bug !! in the main jet. Once I removed the bug, put her back in the water she ran like cut cat.

Those stock coils (nothing but a transformer in a fashion) are at least 50 years old.

I also sent a PM to Super Sportster as he is better at this than anyone I know.

So, just my

[Helmar]

As I think about it more, my coil was also bad, there was oil leaking from it at the output post. A bad coil will also cause problems that sometimes don't show until hot. It's another relatively cheap swap, but these types of issues are why I went ahead and put on electronic ignition.

I also had a electronic ignition go bad on me so I found keep a extra set of points and condenser was less expensive. As soon as I pull that out and put the points back in, I was up and running. That was tricky as I was in rough water when I had to do that..

[John Nelson]

Bearcats are sensitive to tuning. carbs must be clean accelerator pump must squirt. It helps to have the filter as far down stream as possible. I was forever picking pieces of fuel pump out of my carburetors. Valve adjustment take time to get them to middle upper. Good blue spark necessary for starting and full throttle. Im having luck with blue streak ignition parts your favorite application. Ignition timing set for maximum rpm at 3/4 throttle traveling.

[Kelly]

Well I went with a new coil and have been running off and on from my dock for a few hours with no issues. So it appears (optimistic) that it was just a coil. Thanks for the responses!

[Helmar]

Well I went with a new coil and have been running off and on from my dock for a few hours with no issues. So it appears (optimistic) that it was just a coil. Thanks for the responses!

Glad you got it Kelly.