SX/SXi/SXi Pro Big pin motor?

[Luke6:38]

I just purchased an 98 sxi pro this spring and could someone help me understand what a big pin motor is I read about periodically, benefits, and how to tell if mine is?

 

[hornedogg79]

10 bolts on intake = small pin, 12 bolts on intake = big pin

 

[Luke6:38]

thanks. that answers 1 question, mine has 12 bolts = big pin, which maybe the norm for what i have. Is one better than the other?

 

[swannysxr]

1995& up were big pin, connecting rods pin to piston

 

[tor*p*do]

search
small pin cylinder supposedly had better low end torque

 

[Leejetdriver]

" Big Pin " refers to the wrist diameter on the 95 and later engines. they have 22mm pin verses 20mm on the earlier models.

Luke6.38 be careful when buying parts for the late model sxi pro's, a lot of parts are specific to the 98 to 02 models. I have 2 of them and have had to learn the hard way!!

 

[Luke6:38]

thanks for the specifics here. my compression is around 135 each cylinder (the way i bought it) and am considering rebuilding / re-ringing it. If i need to have it bored, this info will be critical.
let me know if anything specific I should know additionally, especially if I end up looking for rebuild kits on line.

 

[97superjet]

^ Big pins are considered a little more reliable also, check your compression with another guage if you can before you tear it apart unless you know yours is fairly accurate

 

[Luke6:38]

my gage is pretty good, and have used it for years. I generally take multiple readings, and is very repeatable. Also saved me from making a bad purchase on another ski which wouldn't start when looking to buy it, and found the compression was 139 front, 95 back. Owner could only say it ran great last year. lol Mine ski runs very smooth, but would like to get the compression back to atleast where it was when new on a tight budget.

 

[Wilke]

You're not that down on compression and you say they are pretty well matched, a fresh hone and new rings is probably all that is needed to get that 10-15psi or so back.

 

[swannysxr]

do yourself a favor while it's apart, mill the head and install R&D timing advance plate. That will wake up that SXI !

 

[Luke6:38]

I believe it came at 179lbs compression new, so would think a jump of around 30lbs would be quite noticable. But if it only took new rings, that would save $ for other improvements!

 

[freestyle 650]

What's your elevation? That will have a big effect on cranking compression, 179psi seems a bit high for a stock motor

 

[Luke6:38]

Hmmm I got it from the owner manuals specs page on the Kaw site. Spec page states Compression pressure is 179 psi. See link. If I am miss interpreting this, please let me know. If I am misreading it, Wilke was correct.
http://www.kawasaki-techinfo.net/showOM.php?view_lang=EN&spec=US&book_no=99920-1845&lang_code=EN

 

[Wilke]

You are reading it right, Not sure thats correct tho. The kawi service manual I have says compression pressure ranges from 125 to 193. I've never seen or heard of one being higher than 150-160 with a stock head, even after a fresh rebuild.

 

[Luke6:38]

Good to know. Based on the past assumption that the 179 was correct, I was believing the motor was kind of tired. With limited funds, I may skip working on motor and look to adding a ss prop this winter to boost performance.