Higher RPM Hiccup

[75_Elim]

Well, I finally got out to Castiac this past Wednesday and had few nice runs but then I developed a hiccup ! It seems that when I got up over 3800 it wants to shut down like it's starving for fuel or it floated the points. It won't die, It just drops off and I have to gather it back up with the pedal. My first thought was the float bowls, but it wasn't on heavy excellerations... It was farther in the run when the bowls should have been filled back up. I did make some adjustments to the Jetovator to increase the thrust angle, would that have caused this problem to start up? Or is this definitly an engine issue. I'm going to replace the fuel pump and points this weekend just for starters, but I'm looking other possible diagnosis and cures while I'm at it. I'm running a 21' Eliminator cruiser with a 454, Perfomer Intake, Holley 750, mild cam and Hardin thru transom exhaust and a Berk JC-A
Thanks
75 Elim

[Old Charger]

Dude..
I've pretty much got the same problem! Let me know how it turns out.

[Brendella]

Hey guys I learned from a guy name bruce that you need a fuel tank vent. It is either on the fuel cap or is a line that runs from the tank to a certain location. this I belive is to prevent a vaccum lock.
I to get the same problem I then open a gas cap to relive pressure then problem solved. I am still working on this situation as to properly route the vent line.
any one out there who can help??

[spectras only]

If you guys were around some older bikes,you may have noticed a tiny hole on the gas cap.This vent hole is to let the fuel being drawn by the fuelpump.Occasionally these holes get clogged causing a vacum to hold fuel back at higher RPM, thus causing fuel starvation.Like Brendella said ,open the gas cap temporarily and see what happens.Marine gas caps designed to have these holes integrated into.There are different type of caps ,the least problem is with the round threaded types,the flip up ones may develop the problems described above.

[Timer]

75_Elim, sounds like you might have my old boat. Is it a Sport Cruiser (20'6") with a bottle of Nitrous in the center floor storage space?

[Clutch]

Hey I just fixed the same problem on my 79 Headcraft.Let's see runs great until topend then the bitch lays down'Right?Back off the throttle and she pulls again?My problem was ignition.Stock 454 i have a unilite dist. and was not getting enough spark at high rpm threw on a msd6al and BAM!!! Baby 64plus mph with a panther pump!!Have been a mechaanic for a long time. Hope this get's ya goin'. if not em me at clutch33@moment.net

[FastDave]

Wow - mine is having the same problem! At WOT the engine RPM will vary by as much as 700RPM - just drops rpm's and then gets them back over and over. Very hard to be FasssssstDave when you can keep your RPM's up!
FasssssssstDave...

[DickDanger]

Ummm, how about something simple like the fuel filters to the fuel pump and/or the carb? -Dick Danger out

[75_Elim]

It seems I'm not alone in this mess !!!
Timer, it is a 20.6 Sport Cruiser but no NOS now. If it was your boat WHY DIDN'T YOU FIX THIS PROBLEM !!!! : ) As for the fuel tank vents issue... I'll give it a shot, but I'm thinking since the boat is a 1975 and vents haven't been put on the tanks in the past 26 years, (even when they were replaced 5 years ago) then maybe they're ok. I would hope I'm not the first to push this baby past 3800 ! I'll also look at that ignition. Clutch, are you running a points system or electronic? And DickDanger, the filters checked out ok !
FastDave...Thanks for the laugh!! I'll post what the fix was once I have it.
Thanks
75 Elim
**** Quick question **** What's the best way to run a jet when it's not in the water? If I'm going to fix this tomorrow, I don't want to be running back and forth to Castaic to test on the ramp.

[Timer]

75_Elim, my boat ran like a top. It left during the divorce and has probably changed hands several times. Yours must not be mine since it doesn't have the squeeze. After you fix your problem, put it in -- you'll enjoy it!

[Timer]

P.S. I had the Hardin Marine 454 with 405 HP, 4 bolt main, blah, blah, blah. As a side note, Eliminator told me to break it in by taking it out and nailing it for a couple of runs. I did, and I never had a problem with it.

[Old Charger]

Bought some filters and a fuel pump today. Looks like one of filters really needed to be replaced (duh). That just might be my problem.. Oh well.... find out a Castaic tomorrow...

[Taylorman]

I had a similar problem when I bought my boat. Turns out, it was water in the gas. I installed a Raycor fuel filter/water separator and the problem went away.

[spectras only]

70's ,80's boats had a filter at the fuel selector[s], and a water separator, built in the bottom of the mechanical fuelpump.The filters should be removed from the fuel bowls [sinter bronze ones]on the carb.The separator should be checked and emptied periodically,and try adding some metylhydrate to the fueltank to mix with water/condensation to carry it out without syphoning the gas out.

[Old Charger]

Went to Castaic today to meet some of the crew and figure out my hiccup. The new fuel filter I put in it did the trick. Had to empty it 3 or 4 times after I left the ramp before the engine would even keep running.
Looks like I'll need to get the tanks cleaned.