1988 BFN - PCM 454 tune up

Revive this old thread.........I just purchased another 1989 BFN that needs the same tune up as my old 88 BFN did. CCFan imembers are an awesome resource. Thanks..

Perfect! Can happen even on a bran new carb.

tbeard wrote: Thanks Tim.... I just received my DUI in the mail from Performance Distributor. I ordered a distributor for a reverse rotation marine engine. Pulled the points distributor out of the 454 and it is not a reverse rotation distributor :( My motor is a reverse rotation 454 but the old dist is for a standard rotation motor. Amazing I will call Performance Distributor in the morning.

Whoops, should have given you the heads up on this one. Most reverse rotation chevies use standard rotation distributors. They can do this because the cams spin opposite if the crank (sometimes referred to as "standard rotation reverse fire"). I assumed you had already put it on- you're going to love the way the boat performs even more very soon!

Yep I saw, and I think you have it pretty dialed in now. Good job on staying focused and not getting frustrated (if you did it didn't show) your results appear outstanding.


Tom you might consider the Double Stack / SFH feels like it adds 2 mph
and you will be 17.4% lighter without even going on a diet.
It's the cheapest 2 mph you will ever buy.
Get the high, med, and low pull with no tower needed.

Tom, just saw your message- looks like you're in business! You don't mess around, ha.

itchy feet

Great news Tom!

Installed the old needle and seat and boat runs like a new one. Unbeliveable.......Thanks to everyone for providng support.

TRBenj wrote: There have been reports of bad Holley needle/seat combos right out of the box- both in rebuild kits and brand new carbs. You may have gotten one of them. If your old one didnt drip, you have the option to throw it back in there and see if it corrects the issue. I'd be on the horn with whoever sold the rebuild kit if it does!

Chalk me up for one who had a bad one right from the rebuild kit. I took it apart and recleaned it but it still dripped out the primary. I ended up doing just what Tim said, and put the old needle/seat back into the carb and the issue went away.

phatsat67 wrote: Usually if you flip the bowl upside down with no float on it and you can't physically blow through the needle and seat it's ok but if you can blow through it at all with just pressure from your mouth than it't for sure bad.

Man I am glad to know I am not the only one to do that.

Easier to just change float level I would think, running a wedge or not?

Yep, thats how I'd proceed.

I had to swap out an old needle and seat on an 86 we had in the shop with a new one because it was just flooding fuel out of the boosters when the engine would run.

I have also found many times rebuilding snowmobile carbs that the new needle and seats were faulty. I got to the point of if they weren't leakin from the bowl vents I would re use the old needle and seats because I was tired of taking fresh carbs apart again and cleaning fuel out of the belly pans.

Did you lower or raise the float?

There have been reports of bad Holley needle/seat combos right out of the box- both in rebuild kits and brand new carbs. You may have gotten one of them. If your old one didnt drip, you have the option to throw it back in there and see if it corrects the issue. I'd be on the horn with whoever sold the rebuild kit if it does!

That would explain the black smoke. I've seen a lot of carbs leaking fuel from the front boosters causing run problems. A lot of times you can diagnose that without even taking the flame arrestor off by listening to the carb and hearing the drips be sucked by the butterflies every few seconds.

At idle it should have a smooth suction sound with no breaks in the sound if you get what I mean.

I have another carb off a boat that ran properly other than leaking fuel from the boosters. I am going to go through that one and see if the idle circuits work better than the one on my carb. Could be something plugged up in the body too. I paid a shop to rebuild it back when I was younger and not confident if I kenw what I was doing inside of a carb.