Performance Mods

dyzionyc

New Member
Dec 19, 2008
16
0
0
ny long island
Hi its me again.
Okey i have ton of experience with 2-strokers ive owned a derbi senda which is a motorbike in spain and i rebuilt that motor and did pretty much everything from port polishing polishing/matching, polishing inside the crank chamber, reeds, pipes, carbs jetting. there area few things i haven't done.
one of those things is increasing compression, now a method i know of is to take the head of the cylinder and with sand paper on a flat surface start polishing it with oil to decrease volume only slightly. and therefore increase compression.

Another thing i want to know what size carb normally comes with these whizzer type engines. and what type/size carb people used and got away with.

Any one know of racing/performance crank bearings out there, anyone use them, how are the results.

Again i was looking for reed mod, i know there are different thicknesses of these and i was looking for a carbon fiber one.

Last but not least mod, if i take the piston connector rod and sanding it down to decrease weight. was wandering if anyone has done this and how much sanding would i get away with without compromising strength.

Off the topic
how long do people break in their engines for. and is there reason to re-tighten the cylinder bolts after couple hundred miles.

Thanks guys.
 

spad4me

New Member
Jan 20, 2008
472
0
0
Arizona Bullhead
I gotta tell you
YES to everything. You can imagine!!!!!!!!!!
I heat cycle my engines for breakin.
Most people just vary the speed Keep it low for a while.
Use a good Air cooled engine oil.

There is a reason to check ALL the nuts and bolts on your engine

THEY TEND TO FALL OFF.
AT RANDOM TIMES.



ps
If you are going to do this

Last but not least mod, if i take the piston connector rod and sanding it down to decrease weight. was wandering if anyone has done this and how much sanding would i get away with without compromising strength.

post a lot of pictures.
You may as well drill the inside rather than sand the rod.
 
Last edited:

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
236
63
up north now
Hi its me again.
Okey i have ton of experience with 2-strokers ive owned a derbi senda which is a motorbike in spain and i rebuilt that motor and did pretty much everything from port polishing polishing/matching, polishing inside the crank chamber, reeds, pipes, carbs jetting. there area few things i haven't done.
one of those things is increasing compression, now a method i know of is to take the head of the cylinder and with sand paper on a flat surface start polishing it with oil to decrease volume only slightly. and therefore increase compression.

Another thing i want to know what size carb normally comes with these whizzer type engines. and what type/size carb people used and got away with.

Any one know of racing/performance crank bearings out there, anyone use them, how are the results.

Again i was looking for reed mod, i know there are different thicknesses of these and i was looking for a carbon fiber one.

Last but not least mod, if i take the piston connector rod and sanding it down to decrease weight. was wandering if anyone has done this and how much sanding would i get away with without compromising strength.

Off the topic
how long do people break in their engines for. and is there reason to re-tighten the cylinder bolts after couple hundred miles.

Thanks guys.
hmmmmm deja vu all over again.

I think I have read this exact post before.