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Stroker crank troubles....so I thought

3K views 18 replies 11 participants last post by  tblumer 
#1 ·
Installed the stroker crank last weekend and I have been chasing my tail all week. I can't seem to get any more performance than before the crank. The low end was better and so was the mid, but I lost some on top.

It acted like a jetting issue and IP2 gave me a dozen things to look for.

After talking with Josh (IP2) about a million times he sent me in the right direction.

He said to work backwards, taking all my mods out of the picture. No matter what I did, it never got better. Well, I went so far backwards I ended up with the motor on the bench last night.

I started tearing it down tonight and got as far as the flywheel and found the problem. Behind the flywheel is totally soaked with gas/oil. The crank seal is wasted. This pretty much explains why I have been having problems.

Just be sure to check your seals, or even better, just replace them while it's tore down. It will be well worth the few minutes to replace them, then to go through what I did this week.marcelo
 
#3 ·
Have you fired it back up since you replaced the seal?

WFO Racing said:
Installed the stroker crank last weekend and I have been chasing my tail all week. I can't seem to get any more performance than before the crank. The low end was better and so was the mid, but I lost some on top.

It acted like a jetting issue and IP2 gave me a dozen things to look for.

After talking with Josh (IP2) about a million times he sent me in the right direction.

He said to work backwards, taking all my mods out of the picture. No matter what I did, it never got better. Well, I went so far backwards I ended up with the motor on the bench last night.

I started tearing it down tonight and got as far as the flywheel and found the problem. Behind the flywheel is totally soaked with gas/oil. The crank seal is wasted. This pretty much explains why I have been having problems.

Just be sure to check your seals, or even better, just replace them while it's tore down. It will be well worth the few minutes to replace them, then to go through what I did this week.marcelo
 
#6 ·
rabeb25 said:
If you would have looked at my thread, when I explained my install, I stated that the key was hitting and binding my seal. I gound mine down. good luck.
The key was removed prior to installing the crank. That's not was caused it to leak. The other seal is leaking as well. I have a feeling the seals were on the way out and with the increased crank case pressure from the stroker made the leaks noticeable.
 
#7 ·
WFO Racing said:
The key was removed prior to installing the crank. That's not was caused it to leak. The other seal is leaking as well. I have a feeling the seals were on the way out and with the increased crank case pressure from the stroker made the leaks noticeable.
I'm trying to visualize the seals guys. Are they a gasket in between the two halves of the case? Maybe point me to one of the pics in the HOW TO thread on the crank. Thanks in advance.
 
#11 ·
eldevioso said:
I'm trying to visualize the seals guys. Are they a gasket in between the two halves of the case? Maybe point me to one of the pics in the HOW TO thread on the crank. Thanks in advance.
think of a shaft sticking through a hole.

There needs to be a seal so the air/fuel mixture doesn't leak out.


The crank shaft comes out each side of the motor. One side has the clutch on it and the other has the flywheel. Both sides need to be air tight.
 
#14 ·
by saying you have 190 lbs of compression, you mean you hooked up a compression check gage to your spark plug hole and yanked on it till it stopped going up?
if so thats a hell of alot of compression! i think mine was only 90 stock.
You got race fuel in that? :)
 
#18 ·
SUX2BU said:
by saying you have 190 lbs of compression, you mean you hooked up a compression check gage to your spark plug hole and yanked on it till it stopped going up?
if so thats a hell of alot of compression! i think mine was only 90 stock.
You got race fuel in that? :)
Actually, it was three pulls at wide open throttle and yes, it is a butt load of compression. My 140hp snowmobile has 145lbs per hole.

I will be running 100 octane race fuel tomorrow and also trying 112 octane if I can get it.
 
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