Fuel/Carb Issues!!!!

[apollo24]

All,

I am having a big problem with my X-18 350 engine, which is almost new, and fresh 4-barrel carb rebuild:

I can run the boat for sometimes 20-45 minutes and (particularly in chop) it starts to cough and giving more throttle just makes it worse to a point where the engine cuts out. If I slowly back off the throttle it won't cut completely off. The boat idles fine, though and revs fine in neutral. And if I let it idle for a bit then plane back off, sometimes it will run for a while.

Seems to me that it is getting too much gas sometimes. I have brought it in three times and they can't seem to fix it. They added an elec. pump and fuel flow regulator for whatever reason last time it went in.

I took it on what was supposed to be a 3 hour round trip down to the beach and ended up having to idle it up around 10 miles of Mobile Bay. Not a happy camper.

Any advice that I can pass on to my mechanic? I would certainly appreciate it. This board has been a great resource for me before!

Thanks, Ben

[Rootsy]

holley carb?

[apollo24]

I believe so, see attached pix.

Thanks.

[SouthernExposure]

Have you checked your fuel for water? Have you checked your pickup tube in your fuel tank. I had a similar problem on a boat I had years ago. The pickup tube would clog especially after being in choppy water. In the driveway it ran fine after being out in the water for a bit I would have the same problem.

SE

[Rootsy]

carter afb... have to think a bit more... :banghead:

[SouthernExposure]

Looks like a Rochester Quadrajet

[Jamesbon]

Sounds like a tough one.

Coils are cheap enough, try swapping that out. I had a similar prob. once, it was the coil.

Good luck!

[Donzigo]

i agree - Rochester. Just rebuilt my Holly carb.

My problem turned out to be the sensor in the distributor.

[Rootsy]

not a rochester q-jet... 10000000% sure... carter AFB (now sold commonly under the edelbrock flag)... generally they (and the q-jets) are pretty reliable and never give you any issues... until they begin to leak internally or externally or get dirty inside, etc... honestly, pretty simple to rebuild.

in either case, if the float level is set too high or the needle sticks open when you are bouncing around you'll pour fuel out of the vent and into the carb and get the results you are getting... (as a side note, if your holley does this add the extended baffles to the float bowls and spring loaded needles and seats)

make sure the coil is good as mentioned before and there there are no loose connections in the ignition system.

good luck figuring her out

JR

[SouthernExposure]

How's the distributor? It looks like a Prestolite. Mine was worn which also gave me some problems you have described. How about the choke is it sticking?

I feel for you

SE

[paperman]

I hope this is as simple as the problem I posted last week. I checked on all of the same things that have been stated in previous posts. I took it out and got the same results. Then I look at the fuel line itself and found that it had pinched off some. Caused when I hit some chop? The line was not secure. I replaced it and routed different, secured the line, no more problems. I hope this helps. :wrench:

[apollo24]

Thanks, everyone!

I did have the coil replaced with a better one; I am thinking the float may not be set correctly, and the bouncing is causing trouble.

I will pass this on to my guy and see if we can't get her going again.

What is frustrating is that it won't do it on the trailer- only when I am out in big chop (where I can get stranded). :)