South Africa's First and Only 2-stroke Forum

OK, so I received a complete motor from a member....
Now this way I can degree it and find true deck height............. Now the owner wants a port job, I'm pretty sure this guy has lots of guts
Another guy told me he already has lots of respect for Cr500 riders... now a port job added on to a CR500...
Believe me I had one for 2 years, I got used to it, the only thing is, there is no room for mistakes, by accidentally twisting the throttle....

We are going to rebuild completely, he already send me a spare jug..... Maybe a PD cool head with 66 dome or modding the stock one....

This is a 96 model and the motor got re-sleeved, but the job was done very poor.... This is also a bit more tricky barrel to re-sleeve.... The sleeve is moving, almost crimping at the bottom, on the top you cannot see the gap by eye, but the oil is coming out of the gap, between the barrel and sleeve, I wiped the oil with a cloth and after about a minute There was more oil, I thought damn, I thought I just wiped it..... Wiped it again and again more oil..... I suspected something fishy until I removed the jug and flipped it over.... Here is my findings.....

Look how the sleeve is coming apart, or might even be fitted like this....





Cylinder head is massive, I just put it on here.... Ran a bit rich.........



Piston crown.........Just for the heck of it...........



Finding true TDC......
This motor has a deck height of 0mm with the current base gasket, it measures 0.03.... Close enough for 0............



Putting the degree wheel on.... She has a Exhaust of 180degrees and 123 degrees transfer duration.... The CR is 180exh on a 500 ccs giving it more bottom/mid.... With such a big motor you can pick port timings more radical without loosing to much everywhere....
A 2-stroke will never be a 4-stroke (damn glad about that ) so I can port for low down power, but when the power starts "kicking in" they will in most cases still have a explosive "hit", if its mid or top, the "hit" does feel a little less when its "low end" port job.... This is way you need to setup the whole motor and chassis/wheels/ sprocket ratios to get traction.... 2-stroke will never be as smooth as 4-strokes...... But the power does sacrifice for that..... 4-stroke fans will disagree with the "more uncontrollable" power, they hate it.......
Anyways imagine, just imagine taking this motor to 194 exh duration with a lekke wide exh port (there is a bridge so lots of potensial for going wide) good transfer with a "low" blow down in degrees... The motor will not like the revs, because of the big single and big parts, but some do that to them for dragging............ I think 100hp will be EASILY achievable....
So we are going to port a smooth as possible considering its a 500 2t LOL ..... aiming for a low/mid range, but peak hp will increase in the top end because of major exh area, time/area angles and changes....
I hope I might ride this baby 1 day................

Here is a pic on the degree wheel..... Looks nice.....

WOW, This is going to kill the owner! LOL. Huge power coming. Nice post B

(08-28-2009 11:15 AM)Bansheesa Wrote: [ -> ]WOW, This is going to kill the owner! LOL. Huge power coming. Nice post B

LOL yeah..........

Hi BVH

Thanks for the pics of my motor

Wow, gr8 detailed measurement

Keep up the good work

Cheers

S

Hello.

I have a cr500 how do I adjust the timing, I can see the the timing marks but I don't know what or where to line it up? help? How to adjust timing on a cr500?

(12-12-2009 01:36 PM)jeryruse Wrote: [ -> ]Hello.

I have a cr500 how do I adjust the timing, I can see the the timing marks but I don't know what or where to line it up? help? How to adjust timing on a cr500?

CR500 has a fixed timing plate.. Those marks are to check timing and to see if CDI is still good if you might run to electrical problems.. If you want to adjust it, you will need to machine the stator plate.. If timing is out you might have a damaged CDI.. This can cause detonation especially if the CDI are 'stuck in advance'..
Please introduce yourself before asking any more questions.. Thank you.