Originally Posted by KayAitch
I'm part way through the running in process on my little KH100 after I did the top end: one run until warm on the centre stand, and 4 rides or so starting at 5-10 minutes and gradually working it up to 30 minutes or so while varying the RPM and not spanking it. So far so good, engine seems smoother and happier already and no signs of the overheating/partial seizure I was getting pre-rebuild. Engine gets nice and warm, I'd say hot to the touch, but there is no loss of power or change in performance, no noises, along the way. It seems to have done the trick.
However, today a nice day of 21C I took it for the longer ride I've done and twice I had the engine stop suddenly on me. I am 99% sure it is not a seizure and is not due to overheating. I am fairly sure it is due to my tank cap not venting properly and the fuel flow cutting. This despite being certain it was fixed after a nice long soak in some white vinegar - now when opening the cap I get nowhere near the sound of opening a Coke bottle like I was getting before. You see, once it stops I open the tank cap and and give it one kick, it roars into life and shows no negative/hot symptoms.
So, I thought I'd ask, what are the signs of a partial seizure? Am I right in thinking there warning signs that show up before hand like gradual loss of power as it gets hot, engine losing it's smoothness, generally getting baggy?
The rebuild has been otherwise flawless until now. Thanks for any help. I love this little bike :)
I bought a kawi 250 air-cooled dirt bike from a shop when I was a kid that had a fresh rebuild. It would run for 15-20 minutes if I remember right before gradually losing power then tightening up. After it cooled for a couple minutes it would fire up and run great for another 20 minutes or so till it happened again. I was breaking it in properly, proper pre-mix ratio......when I took it back to the shop they said they had the piston to cylinder clearances too tight. They offered to fix it or give me a refund (shops were actually cool back then
) so I applied the money towards another bike. That kawi had multiple min-seizures and didn't affect the running abit, not all seizures are solid permanent lock-ups. But they all do damage
You did pretty much describe how it feels...and the motor will lock up temporarily....you'll know if its seizing or not.