tortron

a new engine has all the gears and bearings wearing in yes you dont repeat the whole process for new rings and pistons. no one does an additional 1000km break in process

and glaze the rings cool

im not disagreeing that the bore should be sized to the piston an extended break in might help a piston thats only just over sized, but i feel that unless you know the point at which the piston just starts to expand and then switch it off its not going to work eh

Dr125s and dr200s nang just fine

This simply isn't true

maybe im doing it wrong, but the previous 10 mins of that ride were 60-80 up and down hills, and i was backing it off to stay at 100

is there another way? im riding it around the country roads varying the load and revs. I dont think its excessive WOT *generally il warm it up on the stand once its back together till engine is at operating temp then il go ride it for 5 mins and let it cool again Then il go ride it in the country for 15 mins Do a WOT 0-100 run let it cool Ride home 15 mins Today was just a casual ride after all that. Wiseco says its ok so i dont think im too far off

i would swap in a dr125 engine solely for kickstart, but otherwise no

literally bolts in and has more than twice the power but nah

DR200 is by far superior in every way to the gn engine

slower than a gn250!

if trhe sprocket is loaded up you might want to work out the posibility of the plate tearing

rule of thumb is 1.5 times the diameter of the bolt

No, i dont think theres any matching of these pistons to the barrels out of china (first one i gotdid the same thing you may remember) piston did move freely (i put it in the barrel beforeadding rings or anything to see if the cylinder was going to be too big after i dingle honed it) when i get a cylinder overbored il take the piston in with it, but never bothered with these 150 kits, tbh i dont think any one in the history of these kits has had them go to a machinist

hmm i might just run a flat stone over the rough spots and pop it back in then, ran pretty happily after it nipped up

whad did you do to machine the piston @cletus? did you measure the bore clearances to find the tight spots or just eyeball it? il probably take one of my cylinders and a 160cc piston to a machine shop and tell them to make it fit and not bother with another 150

yea of course its china piston (even the stock one is) i dont think you can even get a not china piston (even weisco ones are nla) Might have to just bore it out and run those cbf pistons, wonder if i can get a japanese one of those

yeah, dont think im gona get another 150cc piston any time soon How much to bore it out to 160?

Piston pin looks as new so i dont think it had an issue with oiling or not being oiled when i put it in plenty of oil up around the cam, so i dont think theres a problem with oiling or am i way off and its just running hot due to timing (tho it is running on 95 and has 2 base gaskets) piston expanding funny or too big? i didnt check it, other than the piston fitting and moving. I guess thats my fault for assuming enough tolerances on new piston and a bore i have honed a couple of times i dunno what to do next tbh

Bugger it Might just gone the cylinder again and send it tbh

nah im sulking

oh boy it soft seized I dunno what happened there, But it lasted the same number of km as that last set of rings that shat them selves. Theres no printed minimum ring gap for a gn125 or dr125, so i used the DR200 specs. and went 0.12mm. (0.1 to 0.2mm min, 0.5mm max) Maybe i need to use 0.2? fuel mix looked happy to me. around 12.5 at wot, as lean as 14 on cruise. i dunno, any ideas what im doing wrong here, or is it just shit bike syndrome

@SOHC has plenty of bike parts like that

https://www.aliexpress.com/i/32788222016.html

never had much luck with colourtune, wideband is so accessable now days