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2- 787 Challengers driving me nutts

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Rockpowersports

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My name is Rock , and I've come hoping for some answers
This year I got into boats for the first time, with a pair of Sea-Doo's (I've worked on skis for several years).

I have a small shop where I fix and sell all powersports.
My problems are 2-96 Challenger 110's, both needed engine work. # I boat I found a 97 GTS parts ski with a 787 and pulled the running motor (a fuel injected one converted to carb) and put it in the boat. It will start, but revs as though it's only firing every other revolution (I assumed it was because of the Fuely crank).
I set that one aside, and purchased a crank from SBT for the #2 boat, and now the #2 boat does the same thingh.http://www.seadooforum.com/images/smilies/FacePalm.gif
Would a stick of dynamite be the best cure?
 
yo rock, you may need adrian to helps you fix this one, and paully, but, you cant make a fuel injected motor a carbed one, --- aint gonna happen, also, rfi came out in 98, and rfi piston sleeves are totally different,................also ???? .............what in the hell, do you have in the injector holes ???? your gonna have to put the proper engines in these skis and go from there ....
 
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The fuel injected motor wasn't my doing, the other motor was all from the boat it came from. Does the ignition pickup ground the mount? I see there is no separate rev limiter, could the module be bad?
 
Rockpowersports said:
The fuel injected motor wasn't my doing, the other motor was all from the boat it came from. Does the ignition pickup ground the mount? I see there is no separate rev limiter, could the module be bad?
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You can use a fuel injected motor, if you swapped jugs, crank, and balancers.

the racers do it , to get the benefit of the extra cooling.

Ask Bill what the combination is,.
 
What about the mag and flywheel , they are different, the mag housing might be able to be reused.

hell even the starter is different clock for the RFI, might want to 86 it.
 
I guess I'm not being clear on this. I've shelved the fuelly motor, and am trying to get the carb one to run right. It will start, but when throttle is applied it acts as though it cuts out every other revolution... Rock
 
Did you put the gate lever in the forward position? You will hit the rev limiter just over 3K and the engine will stutter. It's also possible the neutral switch is bad (on the gate lever), even if you put the gate lever in forward. If that switch is bad you will hit the rev limiter (or not start at all--long beep). To check it quickly you can put the lever in forward or reverse, the boat should not start and will beep at you. When you put the lever in neutral you will get a Beep-Beep. Trying to start in Forward or Reverse you will get a long Beeeep.
 
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Like I said, if you didn't move it to the forward or reverse position when you tried it, it won't rev past 3300 I think and will bounce off the rev limiter.
 
Can the Guardian cause any of the concerns that the OP is having?

It is an easy test, simply disconnect it..
 
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racerxxx said:
What is the Guardian?
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Not sure what all boats have them or if they are a Merc only engine setup..

But it is a black box under the console that acts as a rev limiter while shifting between gears... As it fails,, it causes runability issues for some reason... [MENTION=16022]Dr Honda[/MENTION] can confirm what boats these are on and he has extensive knowledge with them.. I will try to do a searc and post a link or two myself..
 
In neutral and the engine running you will hit a low speed rev limiter @ 3300 RPM. Once you shift from Neutral you have full RPM until the upper Rev limiter is reached. To the best of my knowledge the rev limiter is in the MPEM. We first need to confirm that he is shifting out of neutral and into either forward or reverse, which I would assume he hasn't as in post #9
 
Yep, Guardian is merc only, I never noticed my 951 carb is rev limited in neutral, it isn't as far as I know. The description sounds like rich four stroking to me, if not then maybe bad coil/ignition issue?

Splash it, I really can't hear an engine run on the trailer, it's no way to test except to confirm if it can be splashed. If it runs, I splash it unless it's obvious it's not going to run.
 
Coastiejoe said:
that was my thoughts once I got to thinking,,, thanks,,,
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Yeah, only merc would think of doing something like this, just like those outbored guys always making extra work for themselves.

Seriously guys, don't tell me seadoo does this!?!?!?!

Anyway, we just fired up a big Johnson e-tech on the muffs, good god these things sound mean out of water! :)
 
Sportster-2001-951C-Stock said:
Yep, Guardian is merc only, I never noticed my 951 carb is rev limited in neutral, it isn't as far as I know. The description sounds like rich four stroking to me, if not then maybe bad coil/ignition issue?

Splash it, I really can't hear an engine run on the trailer, it's no way to test except to confirm if it can be splashed. If it runs, I splash it unless it's obvious it's not going to run.
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29.jpg


Let's hit the brakes here until he confirms the shifter before we even break into some crazy idea on carbs etc.... Remember--his other boat he's working on had the SAME problem(see post #1). So you mean to tell me two boat have the same problems? Once he confirms: A. He's not in neutral (Should be hitting just over 3K on the tach at full throttle but on the rev limiter). And then B. If it still hits the 3K rev limiter in forward (throttled up) the switch needs to be tested with a DVM. Stick to the KISS theory.

They limit the throttle in neutral for safety, the same reason they don't want you starting the boat in forward or reverse.
 
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Sportster-2001-951C-Stock said:
Yeah, only merc would think of doing something like this, just like those outbored guys always making extra work for themselves.

Seriously guys, don't tell me seadoo does this!?!?!?!

Anyway, we just fired up a big Johnson e-tech on the muffs, good god these things sound mean out of water! :)
Click to expand...

I am certified on OMC engines. I used twin 300's on my 25 foot combat boat. They were monsters. Ran unreal and BARKED when you were not in the water. Which was pretty often. Had to step up to neoprene water pumps as the rubber water pumps couldn't take the high revs when out of the water.
 
WOW! Snowmobiles and motorcycles (that's what I work on most) don't have a rev limiter in neutral. Do I get a doofus award? Thank you all for the info, and especially Racerxxx for hitting the nail on the head, "keep it simple stupid" as my dad used to say.
 
Hey Racerxxx, That fuelly motor has the stock crank, pistons, flywheel and cyl., but carb motor- stator, and housing. Is there any power or other issues I would have running it that way (it does run).. Rock
 
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