Sounds like you're emptying the bowls at speed. Check that your pump is maintaining adequate pressure and your fuel lines/filter aren't restricting flow.
JUST GOT MY 18 STARBUCK OUT FOR TESTING THIS WEEKEND, RUNNING A 468 B/B CHEV, OLD STYLE CLOSED CHAMBERED OVAL PORT HEADS, FLAT TOP PISTONS, COMP CAMS JET BOAT SPECIFIC CAM(564i 567e LIFT 278i 292e DUR.) WEIAND TUNNEL RAM W/600 EDELBROCK CARBS JETTED 3 STAGES RICH AND CHOKES REMOVED, ROLLER ROCKERS,MSD PRO BILLET DIDT DIST & 6A BOX, BASSETT OT HEADERS, BERK PUMP 12JB w/B IMPELLER, (SUPPOSALLY)PLACE DIVERTER. THE BOAT STARTS IDLES AND CRUISES GREAT ACCELS HARD BUT STOPS PULLING AT 5200, YOU CAN DETECT VERY SLIGHT POPPING FROM BACK SEAT BUT NOT FROM DRIVERS SEAT, ALMOST AS IF IT HAS A REV LIMITER, NO CHIP IN MSD BOX THAT I CAN SEE. SEEMS TO BE VERY LEAN, TOP SPEED BY SPEEDO, 60, I HAVE BEEN RESTORING THIS BOAT FOR 2 YEARS AND JUST GOT IT IN THE WATER FOR SOME SHAKEDOWN AND AM NEW TO THE JET BOAT SCENE AND WOULD LOVE SOME POINTERS WITH THIS SETUP, THANKS ROB
Sounds like you're emptying the bowls at speed. Check that your pump is maintaining adequate pressure and your fuel lines/filter aren't restricting flow.
Using a H/P mech. pump shows lots of pressure 8.5 psi(thats even more than these carbs are supposed to see) but it does not have any idle or flooding issues, I have not looked at the gauge at rpm, rear seat blocks veiw from drivers seat but should be able to ck. from rear, but there is no surge or starvation feeling, more of a rev limiter feeling, Thanks Rob...
No rev limiter on the MSD 6A box, unless one is added.
http://static.summitracing.com/globa...msd-8738_m.jpg
Or is it the MSD 6AL box? That one will have the rev limiter in it.
I don't know squat about Edelbrock carbs, but I'd agree with roostwear and make sure everything is square on the fuel side of the equation.
I battled a similar issue labor day weekend and found that my back carb's (I run Holleys) float levels were off. It wasn't by much...........but still caused the problem.
Not saying it's fuel and couldn't be anything else. I just think it's a good place to start. At least make sure everything is working as it should.
I had similar situation. Pulled like a mad man to 4800rpm then started popping. The boat had been sitting a while so i checked valve springs. The valve springs were week. I added a shim under them and the popping cleared up and it pulled to 5000rpm. thats my 2cents.
Do the MSD boxes need a chip of some sort to work propperly ???? I think they have to have at least a chip in to complete the surcet. Valve springs when weak cause all kinds of problems, Popping in exhaust, poping through carb. This is easy to check. Run the engine on the trailer and hit higher rpm than normal, if it is a spring you will hear it. You may also have a broken one. Which will also show in popping at low rpm. If springs are OK I would put money on the MSD stuff.
Good Luck
Jim
All of the valve train is new, cam springs, push rods, rockers etc, the popping is hard to detect, you can't from drivers seat, still acts like a rev limiter to pulls hard right to 5200 and stops, have to ck on the MSD box, Thanks Rob
Just because its new does not mean it is right !!!!
Jim
We just got through fighting the sane problem on Ken F's boat. Went the whole nine yards and it ended up being the 6AL Box.
Duane,
Thats what Ken told me. What a bitch. I have worked and watch so many NASCAR teams fight the MSD problems over the years. Nothing worce than loosing a $1,587,345.00 race because you have already swithed to your back up box halfway through the race and now the back-up is failing. That is why I choose not to run them. I hate failures. In a boat if you are down river you are screwed, up river its ok. On a lake your just plain ****ed in the middle in the middle of the week. In the desert you are snake bate, and you loose. In a boat you even add more to the mix WATER and electronics hate water, so you have heat and water. Very scarry. A very wise man told me many years ago Keep It Simple Stoopid.
Jim