SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: barefootin on March 30, 2012, 10:43:56 AM
-
To recap: 17’ Sutphen (see avatar)
re-built 460 20 over w/mild headwork (exh 2.190 int 1.710)
800DP Holley rebuilt
All Mallory ignition (6m-2c, blaster 3 coil)
re-built and blueprinted Berkeley pump w/stuffer & place diverter and new grate stuff
Edlebrock Performer 460 manifold (specs say it needs 9.5-1 comp)
Crower 460 cam (specs say it needs 10.25-1 comp)
Previous owner was going to put a blower on it and therefore had 8.1 compression on rebuild…would this cause the problems since cam and intake seem to be a miss match…
Here is the problem…boat will come out of the hole fine but when it hits around 3500 rpm it hesitates as if you are holding on to it…kinda like a skiier on the back end pulling hard across the wake…it tops out around 45mph or so …and it just wont “open up completely”…don’t know how to describe it better than that…secondaries are opening up and nothing messed up in pump or grate…timing is around 30 degrees…
Any thoughts would be most appreciated
-
go up 2* in timing and check plugs dont go past 36* total what impeller is in it
-
Correction: It is a MSD (complete) ignition system w/ marine cdi, marine distributor, and coil and wires...
the impeller is aluminum A that has been cut and machined during blueprinting by ARS and they changed the bowl also...
the timing on this setup (MSD) is controlled by distributor springs and advanced stop bushings...so not sure how to add @degrees other than advancing it @3000rpms...is this correct
-
Correction: It is a MSD (complete) ignition system w/ marine cdi, marine distributor, and coil and wires...
the impeller is aluminum A that has been cut and machined during blueprinting by ARS and they changed the bowl also...
the timing on this setup (MSD) is controlled by distributor springs and advanced stop bushings...so not sure how to add @degrees other than advancing it @3000rpms...is this correct
there are colored bushings and springs inside the dizzy, go to the msd website and down load the instruction manual for your dizzy. and go from there. if the impeller was cut it is no longer an A
-
Could be running out of fuel check float levels
-
Maybe take a ganders at the jetting and a fresh set of plugs look like after runnin it.
Do you have a fuel pressure gauge that a passenger can monitor? What kinda fuel pump?
Sent from my ADR6400L using Tapatalk
-
found out the msd ignition 6m-2L has a rev limiter...mine had a 4000 module so pulled it out and went for a spin...first time i have enjoyed the boat since buying it in nov...hqenbeen out about 5 times for 20 minutes and came home and fretted over the performance...well it ran like a scaulded dog and only took it to about 4600rmp and was cruising about 55 with more power available...just didnt want to get too greedy on first test run...now have to order the 5000 module package which has 5 modules graduated at 200rpm from 5000-5800rpm...$71 more and I will be set...
thanx to all that offered their suggestions...
-
^ see.....that's why I don't run a limiter...I let the valves tell me when to shift :o
-
found out the msd ignition 6m-2L has a rev limiter...mine had a 4000 module so pulled it out and went for a spin...first time i have enjoyed the boat since buying it in nov...hqenbeen out about 5 times for 20 minutes and came home and fretted over the performance...well it ran like a scaulded dog and only took it to about 4600rmp and was cruising about 55 with more power available...just didnt want to get too greedy on first test run...now have to order the 5000 module package which has 5 modules graduated at 200rpm from 5000-5800rpm...$71 more and I will be set...
thanx to all that offered their suggestions...
I made that suggestion to you on performance boats a week ago!
-
I made that suggestion to you on performance boats a week ago!
lol he asked this ? on 3 different boards and where does the correct answer come from.. rock on scjb
-
Hmmmm 4000 rpm chip, and the tach showed 3500 ? You might want to look into a new tach too. ???