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Discussion Starter · #1 ·
Here are the pictures courtesy of lucky topher z28 who did the original writeup of the IP2 FCS crank install. How about the experts who have attempted or know how to do it post comments on each one, and then we can have an admin copy and paste the bastard to make sense out of it. That was one of the best 'stickys' we had.









 

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is the full circle crank so the bottom end is ballanced and it can rev higher while at the same time not vibrating the $%^* out of the bike?
 

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Discussion Starter · #7 ·
blueR1cag said:
is the full circle crank so the bottom end is ballanced and it can rev higher while at the same time not vibrating the $%^* out of the bike?
I think that's partly it..but i think the crankmoves farther giving it a longer<?> stroke...
 

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Got mine done the other day.If you are capable of tearing down the motor and putting it back together it is really easy to do theres not that much of the crank case that has to be removed.The end results are worth it I would say definetly worth the price.
 

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Big Bore KIT porting only done on exhaust port;

with stock crank:

widen to 31 mm

raise roof 2mm

=============

with SFC

exhaust port :

widen to 31 mm

raise roof 4mm

lower floor 1mm

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warning :dont try to match exhaust chanell with port size or channel can bust open (holed) , so you can tapper cut only



SFC instalations:

veriaty of cylinders out there made by different companies so squish clearance can vary

squish band must be set at 0.5mm :

less than that means piston hit the head , any more will reduce compresion and engine will not make any power or may not even run ..

on most engines 2mm spacer should not be used , instead stack 3 to 4 base gaskets , each gasket is 0.3 mm so 5 will be 1.5mm .. some guys used only 3 gaskets ..

if more than 5 required then must use 2mm spacer and no gaskets ..use yamahbond 3 to seal ..

never use any type of sealant or paste on paper gasket , because when stacked the sealant may cause it to slide sidways

you may use smallest amount on case joints only


forward this to anyone with FCS crank:

1- case must be trimmed to make 0.5 clearance between crank and case,..can trim with half moon hand file , must trim at 45 degree angle , only cut from case centers

2-must instal spacer supplied or gaskets under cylinder

3-must remove the washer on 4 cylinder bolt so bolts can reach deeper

4-it maybe possible to run without base gasket as long as piston dont hit the head , in this case use small amount of yamabond 3 to seal ..check all clearances , 0.5 clearance on all parts required , if piston hit the head add one or 2 base gaskets till it clear

5-stroker crank increase dispalcement to up to 54 cc so is vibration , make sure there is rubber mount on pipes mount and all fasters torqued down

6- must port cylinder and instal pipe and jet kit

7- my pipe sold out so you can modify stock pipe as follows:

cut 1inch from header , add 1inch to belly , such mods make more torque than my pipe for indoor but fall short in outdoor tracks
==
 

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Before you bolt it all togeather, do a squish test and adjust base gasket for a .5mm squish. This is EXTREMELY important!

Use a piece of lead solder and place it on the piston over the wrist pin.
Turn motor over by hand slowly.
Remove solder and measure it with calipers.
Target .5mm

In order for me to get .5mm, I had to remove the spacer and double up two gaskets I made which are thicker than stock.

This was a HUGE difference in performance.

With the spacer I had 1.2mm squish and 120 lbs compression.

Without the spacer and using two gaskets I made, I have .5mm squish and 180 lbs compression.
 

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when assembling the circle crank do you reuse the lower crank/rod pin or does the kit come with a new one? if not, am i going to need a machine shop to press the 3 pieces together? the reason i'm asking is cuz i'm worried about alignment and crank assembled out of balance from the get go.
 

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whiskey said:
when assembling the circle crank do you reuse the lower crank/rod pin or does the kit come with a new one? if not, am i going to need a machine shop to press the 3 pieces together? the reason i'm asking is cuz i'm worried about alignment and crank assembled out of balance from the get go.
The crank comes with the connecting rod assembled so all you need to do is add your piston.
 

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thanx

dude thats too easy, $60 is complete. you can't beat that. i hope it's on my door step when i get home tommorow. i won't be able to sleep tonite!
 
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