Hey guys, I listed earlier about problems with my 93 GTX. I have a problem with compression leaking back through the back cylinder intake and through the carb barrel. After removeing the rotery valve case I noticed that the forward cylinder(which seams to run good)valve timing is right but the back cylinder is wrong.How is that possible. Are the crankshaft lobes exactly 180 degrees apart. I can put a screwdriver in the forward cylinder and when it is at TDC the back cylinder is not at BDC. It is about 25 degrees off. Is it possible for the crankshaft main journals to move. Thanks for your help.
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Re: Crankshaft question
Yes! As i understand, cranks are pressed together under tonnes of pressure during construction. As they are made of individual parts, it is possible for the crankshaft to become out of phase. You need to get yourself a new/rebuilt crank that has exactly 180 degress phase difference, otherwise you will have engine problems/damage.
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Re: Crankshaft question
Hey Bill, It is acually the 587 engine. Does that have the same problem with the crankshaft? Thanks.93 SEADOO GTX
OIL BLOCKOFF KIT
DG EXTREEME PERFORMANCE PIPE &WATERBOX
DG REV LIMITER SET AT 7,000RPM
95 SEADOO XP
NEED MOTOR.....
EMAIL IF U HAVE A BLOWN ONE FOR SALE
OR REBUILT ONE
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Re: Crankshaft question
Thanks for all your help guys. I am going to take the engine apart this week. Do you think I can have the crankshaft repaired or should I just buy an overhauled one. Also, we connected a aftermarket rev limiter on this ski and the first time we connected it wrong. We connected the red/black wire to the CDI rather than the coil. Could this cause preignition which could of been the cause of the crank damage. Is there anything that controls fireing order. For example, I connected the aft cylinder spark plug lead to the forward cylinder and it ran fine on that one cylinder. (the back cylinder was not connected). Are they constantly fireing. Thanks.93 SEADOO GTX
OIL BLOCKOFF KIT
DG EXTREEME PERFORMANCE PIPE &WATERBOX
DG REV LIMITER SET AT 7,000RPM
95 SEADOO XP
NEED MOTOR.....
EMAIL IF U HAVE A BLOWN ONE FOR SALE
OR REBUILT ONE
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Re: Crankshaft question
Buy a rebuilt crankshaft.
No the wrong wiring did not hurt the CDI and it could not change the firing order. The coil fires both sparkplugs at exactly the same time. It matters not which clyinder you run the sparkplug wire to.Last edited by Bill O'Neal2; 01-25-2006, 01:44 PM.Bill O'Neal <br>
WCM
<a href="http://www.watercraftmagic.com"
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Re: Crankshaft question
I was wondering should i just get my crankshafted twisted back and tig welded. i have a local shop that will do it for $70 bucks. Or do u recommend someting else bill? is so please give me some places to look thanks Adam93 SEADOO GTX
OIL BLOCKOFF KIT
DG EXTREEME PERFORMANCE PIPE &WATERBOX
DG REV LIMITER SET AT 7,000RPM
95 SEADOO XP
NEED MOTOR.....
EMAIL IF U HAVE A BLOWN ONE FOR SALE
OR REBUILT ONE
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Re: Crankshaft question
When you get your engine out, there are a few test you can do before you
tear it down.
You will need a dial indicator (screws into the top of you head), and
a degree wheel.
With the dial indicator installed in the number one, bring it up to TRUE
TDC, affix the degree wheel to the PTO (BACK) or MAG CUP (FRONT).
mark a reference point at zero.
Then move the dial indicator to the number 2, bring it to TDC and check
your degree wheel.
It should be EXCACTLY 180 Of your first, if it is off 2 - 3 degree's.
Get a rebuild, this will help you out before you tear into it.
Get the new one welded too, though most shops do this anyway.
Hope this helps, has saved me many times.
L8TR
Rudedog
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