i read a few things online and stied to understand what things will do but gave up and decided to do a trial and error on an old engine that i didn't care about. i know it isn't as smooth of cuts as the pros but how do you think i did?

before:






After:






as you can tell the dremel slipped a few times but it only scratched off the surface and didn't do any damage to the sleeve. the pics also dont show any depth but oh well

when you modd a motor a little goes a long way.the crank don't look too bad,you may have overdone it on the sleeve.but the only way to know is to run it.how does it run?

i haven had a chance to run it yet but ill report back when i get a chance to run it. its been raining here alot

i ran it today and saw a big change in performance. it was faster and more powerful. one question though, how would i know if i went to far, how would it run?

if u went to far it wont right properly

im thinking about moding another engine but what can i do to increase rpm's

dave don't touch the exhaust port man. you went overboard with the exhaust port from the looks of it. you should never cut the bottom section of the exhaust port. if you cut too much from the top of the exhaust port you also kill the bottom end torque.

i did the same mistake as you on my first modified engine and it ran bodgy after this, so just keep this in mind.

that motor is going to have hard time making run time for sure.

yes tom i did go overboard and it does run boggy on the bottom but is faster on the top. as far as taking away from the bottom of the exhaust it was more of surfacing it and not really taking away from it but i hear you and will keep that in mind next time.

rocca, why do you say that it will have a hard time making run time? you are right but what can i do next time to prevent that from happening?

i know that taking a little away (no where near as much as i did) from the top of the exhaust port will increase rpm's but what else can i do to increase rpm's


thank you for all your replies

did you use a large dremel bit on the sleeve?

the bit i used the most was about 1/8 inch wide and 1/2 inch long

please anyone?

change the engine timing.

Id suggest doing one mod at a time and noting what it does. A lot of people tell you wives tales on what does what, but till you find out for your self you wont know for sure.

Cheers MM