96 challenger runs on trailer but not in water

[SRUSH]

i am at my witts end with this, it will run on trailer but boggs and cuts out about 3000 rpms max and it cutts out. i have checked and changed and cleaned alot of things with the same end results.

changed rectifier
checked stator all good
rebuilt carbs
new fuel lines
bypassed on off fuel selector
clipped plug wires 1/4 in
new battery
many plug changes
new fuel filter
checked and cleaned baffle
new fuel
compression is 145 each cyl

my last water test was yesterday and it still wont run right on the water. i keep on getting oil fouled plugs so can i try a hotter plug than the br8es? or do i need to adjust the carb settings. tonight i was giong to re adjust the throttle cable and oil pump cable and try to set the lsa and check to see that the hsa is fully in.
the motor was running perfect in my 96 gsx and i took it out to get this boat up and going for the rest of the season.the carbs are off the gsx and the plugs would get a little oily but i figured a little rich is better than lean. i had no problems with it all season since i rebuilt it and got it going so i dont understand why im having this happen now.

 

[SRUSH]

could it be retarded igniton timing? does it have to be done by a dealer with the special tool or is it something i can do

 

[timmyboy76]

did list

never mentioned, RAVES being inspected/cleaned. Just came across same issue, kept fouling out my mag plug, on port motor...tore airbox off, made sure carbs were "synced"..never thought it would've been the RAVE since I had just went threw them when I got the boat. Removed it, hit the valve on a wire wheel, and now all good..7100rpm ALL THE TIME.

 

[timmyboy76]

use the electronics...rectifier, coil..etc from the GSX and see if it'll work. All that craps, interchangable.

 

[SRUSH]

yeah i swapped the rectifier from the gsx and stole the starter from it too. i did check the raves out too they were a little oily sprayed them with some brake cleaner not too dirty. i did the checks on the stator with an ohm meter like ive read checked for grounding and resistance all checked out good

 

[SRUSH]

what about running a hotter plug?

 

[timmyboy76]

SO....you took a "perfectly" running GSX, stole the motor out, and installed it into your challenger correct? AND no, it will not run pass whatever rpm, but will rev out of water?

Make sure the reverse bucket is lifting up, and other than that, did you switch carbs at al, or remove the intake manifold to expose the rotary valve, all is good, then i'd look at fuel delivery, pull the baffle/sending unit out, inspect it, replace all fuel line, make sure the fuel line is correctly installed onto the carbs, pulse line connected and good..etc.:cheers:

 

[SRUSH]

yes that is correct getting a little chilly to ride the ski so i thought the boat would extend the season lol. but i didn't remove the rv cover since installing it into the ski earlier this year when the timing was set. yesterday i did pull the baffle and it was clean but i ran some carb cleaner through the on and res tubes and i bypassed the selector switch and ran it straight off of the res nipple. lines are good carbs are clean and newly rebiult the reverse and foreward neutral saftey works, limits rpms to 3500 in neutral and on the trailer i put in foreward and will pass 7000 rpms when i throttle it. just when it is in the water it runs like crap

 

[SRUSH]

well i was just messing with it a little and its a real hard start now. cranks for a second and quits then i get a single beep. have to unplug cap and put it on two or 3 times before i get the double beep. and i t used to run great on the trailer but it is backfiring now when i try to rev it up and the plugs are oily and there isnt much fuel on it mostly oil. can my rotary valve timing change without the brass gear stripping? or is it going to deffinatly be stripped?

 

[timmyboy76]

think it be tuff, to "skip" a tooth. Hows the oil level between runs, do you notice a drop in level..ike the seals are leak'n? Make sure the battery is charged and off/disconnected while not in use. Pull the raves, clean them, install new plugs....think its something simple, just not being attended to. Hows the compression, might as well pull carbs and give another once over along with inspect'n/cleaning the xcellerator pump..:cheers:

 

[SRUSH]

ok i took carbs off and pulled rotary cover and the valve and cover look ok, and there seems to be a little play it it and i dont think there should be.:banghead:should there. how is the easiest way to pull the shaft to check the gear?

 

[timmyboy76]

there be a slight play to it. Remove the plugs and the grey shield from back of motor to exposethe pto. Now rotate the pto and at same time, watch the rotary valve. It should move at all times, the pto is turning...also, put long screwdriver down the front(mag) cylinder and rotate the pto until the screwdriver/piston is at top of cylinder, then look at the rotary valve. It should be closing off the back(pto) port hole opening, with the 2-edges of the valve at, say 10:30ish and 4:30ish..:cheers:

 

[SRUSH]

well i looked a little closer at it and the little bit of play was where the valve attaches to the shaft and the shaft itself was pretty solid. i rechecked the degree and it is correct. i just keep on getting oil fouled plugs now and backfiring. i checked the oil pump adjustment and it is lined up at the hashmarks. my hsa was almost a turn out and lsa were about 2+ turnes out so i set the hsa at 0 and the low at 1.5. when i check the plugs they have oil on them but dont smell too strong of gas. i did a visual spark test bt grounding a plug to the head and there is spark, now if it is fat enough or blue enough i have nothing to refrence it to. is there a accurate way to test the output of the plug wire? why is there so much oil on the plugs if the pump is adjusted properly

 

[timmyboy76]

rave valves stick'n, throttle linkage is not "synct", ..but those settings were way off, lsa/hsa, unless you dont have an ecellerator pump, then that is the reason of those other settings....bad inner seals.

After confiming the list above, try a br7es plugs.

 

[SRUSH]

about the raves, i had the motor up to 60 over last year and the raves were relieved for that bore. well the motor was remaned this year and resleeved so what effect will the shorter rave do with a stock bore

 

[SRUSH]

and as far as carbs being in sync when i have throttle closed both are closed and at wide open they are both opening at the same time and same distance as far as i can see.

 

[SRUSH]

i also could not see where the fuel squirts into the carb as i have read in some of your other posts

 

[timmyboy76]

i also could not see where the fuel squirts into the carb as i have read in some of your other posts

if your carbs (pto) dont have the xcellerator pump, then that could be the reason for the lsa/hsa settings.....just looked up the settings for that yr/mdl/motor of ski, and the settings should be. 1=lsa, 0=hsa.,and DOESNT have xcellerator.

Pop the black caps off the motor, where the raves are, and pull the nipple of the bellows up, IF ANY resistance, undo the allen bolts, and remove the units, and clean the guitines.

 

[SRUSH]

what do you think about them being relieved? i have the stock ones off the "blown motor" should i put those in. also it there a chance its not a fuel problem and it is an ignition problem? like retarded ignition timing or a defective mpem?

 

[SRUSH]

codes

i am begining to wonder if i can fix this or not

 

[SRUSH]

eureka! i think lol

what i found last night after i cleaned the raves which were not too dirty just oily was the short vent line i think that goes from the crank case to mag carb was closed off explaning my lack of fuel. when i changed out motors it stayed on the old block so i cut some new line and used it and apparently i cut about an inch long and at first it was ok but when it sat for a little while it collapsed on its self kinking it. and that is what pulses the diaphrams to draw fuel in isnt it? well anyway i now have a free flow of fuel thruogh the filter. it was like midnight and i didnt really want to fire it too much and wake the neighbors so i will mess with it a little bit shortly:hurray:

 

[timmyboy76]

rite-on, man..! hope it all worx, bud.

 

[SRUSH]

well it still wont run in water.it will start and idle fine but give it any throttle and it will die about 2500 rpms. does anyone have any other ideas.

 

[timmyboy76]

try with the gas cap off..?

 

[SRUSH]

i did that before on the trailer but not on the water, i havent heard and kind of pressure when i crack the cap. could popoff pressure have anything to do with it?