twinsted crank, or oddly failed MSD enhancer?

Mouthfulloflake

ISJWTA member #2
Location
NW Arkansas
here I dumped ( way too much) fuel straight down the carb, no love, it nearly rumbled at first, then it nearly locked up once, then it just spun freely.
Normally this engine would run (and even rev with the the throttle) a few times on a spoon of fuel...

 
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Mouthfulloflake

ISJWTA member #2
Location
NW Arkansas
so there it is, any ideas?

I realize the odd noise is hard to understand and hear, but the engine has never had that nearly LOCKUP sound when starting before....

MattE, maybe its such a slight difference in the TDC/BDC that I cant tell it by eye? would that make it absolutely not start?
 

Mouthfulloflake

ISJWTA member #2
Location
NW Arkansas
Scorn, thanks for the input.

Ill assume you mean BIG end Rod bearing?

if the CDI swa[p yeilds no results, I will remove the head, and hold down the slugs and roll it back and forth via the coupler , maybe I can fond the slop.

thanks guys!

this is an oddball scenario to me for sure.
 

Matt_E

steals hub caps from cars
Site Supporter
Location
at peace
If the crank twist were imperceptibly slight, it sure as hell wouldn't be a problem for the motor. :biggrin:
 

Mouthfulloflake

ISJWTA member #2
Location
NW Arkansas
pulled the ski out of the water today.

More discovery, troubleshooting to follow.

rear crank seal is there, and looks normal Idok,

Im starting to wonder if there is a hole in the bottom case.

more info to follow ....
 

Mouthfulloflake

ISJWTA member #2
Location
NW Arkansas
well hell.

I pulled the engine out, expecting to find a bad crank, or a hole in the bottom engine case.

Nothing I can find, piston wash looks good, everything turns and moves as it should.

so I removed the E box, got some rusty connectors, MAYBE the msd cdi is bad, or maybe it wasnt getting the proper pulse to time the ignition.
plan to clean those and try a few differetn cdi box to try and figure out what the hell is going on.

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Matt_E

steals hub caps from cars
Site Supporter
Location
at peace
There's your problem right there - you got a bunch of change coming out of the engine.
Also, that stator doesn't seem to be right for the motor.


:haha:
 

Mouthfulloflake

ISJWTA member #2
Location
NW Arkansas
haha, the stator is for one of my dual sport bikes...


there was some real slight pitting on the front dome, I guess I really shouldnt be running any 87 octane fuel.
the domes are 37cc too, I had always though they were 35.
 
whats the compression?

if you are anywhere near 175 or 180 your boat will run like ASS on 87 octane..





you bendix also spun when you initally hit the start button...I wouldnt count the front cover guts out yet












you know..I watched your fuel dump vid 3 times....it behaves EXACTLY as a surf boat does when it has water in the bottom of the crankcase.....you prime it, it stumbles but rewets the plugs......


trying flipping the boat completey upside down, turn the motor over by hand and see if any water comes out...
 
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kid4now

X-H
Location
Miami Fl
Ok so I think I read the hole post so forgive me if I say something that was said or already checked.

From everything said so far I put bets on your msd/cdi. I know you have pulled the engine so it wont hurt to go through it all and check it out. But before you did, did you pull the plug caps ground them and and crank the ski with the plugs in to see if you get that intermittent locking up symptom? Possibly due to off timed spark. Did you try swapping out the cdi? MSD enhancers and great performance enhancers but when they go bad they do funny things.
 

Mouthfulloflake

ISJWTA member #2
Location
NW Arkansas
Kid4now,

I verified spark, and in the process ( there is a vid) the engine never locked when the plugs werent firing)

Idok,
its an old worn out motor, it shows 150 psi in each hole with the ada head and 37cc domes, been like that for the few years ive been running this motor.

plugs arent wet.

bendix does that about 1 out of every 50 starts. front cover guts were all fine

Waterhawk, would would deglazing the cylinders gain me? it runs VERY strong like this ( for what it is)

- update.

I reinstalled the head, put in an old stock CDI, and it fired right off.

so now I need to go back and try the msd, and see if it was the dirty connectors, or the MSD>

Ive had 2 MSD units fail on me, neither gave these symptoms.
 
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