AMCQ46 KH125 thread
Posted: Wed Oct 14, 2015 11:58 am
Had this little 1976 KH125 for about 3yrs now and the back story is that I also owned it about 20yrs ago as well ...... when my uncle gave it to me when he retired and left the city. My uncle bought it new and used it for commuting and when he stopped working it stayed in his shed and when he moved away from Brum he asked if I wanted it.......... even though I had no use for it back then, I said "OK", as it was a free bike. 
Anyway, it then sat in my shed till one of my mates asked to buy it to pass his test on, and I told him he couldn't buy it, but he could use it and give it back to me when he was done with it. he passed his test and then passed the bike on to someone else under the same rules, they MOT'd and taxed it and passed it on a total of 4 times, by which time we had all forgotten about it
so roll on 14yrs and I am reminded about the bike when a friend is looking for a commuter bike for her son, so the search starts and after a few weeks it is tracked down to somebody's granny's garage, where it is hiding under a blanket........ 7000miles on the clock and only a bit of surface rust on the chrome......... now it is a classic I am interested again.
I get it home and clean the carb, throw out the airfilter as the foam is crumbling, and I get it started. Ride it about 2 miles and it starts to splitter and it dies
, and I need to get towed home........... turns out all the crank seals were perished and I had lost all the crank case compression to suck the new charge in from the carb, then up to the combustion chamber.
I tell our fried that it will take too long / cost too much to fix and tell her son to look else where, but in truth I didn't what a 17yr old thrashing this old family airloom .... it needs cherishing and looking after in its retirement.
get gasket set and new bottom end brgs and crank seals from China for about £20 and strip it down................ a 1970's air cooled 2 stroke single is about the simplest thing in the world and its done in a few nights... only need to remember the impact driver for all the "soft as feck" Philips head screws that they used back then. Piston has seen a few seizures, but I clean it up just to make sure it is a runner.
result...... it runs, but when it gets very hot it starts to cut out [after about 10 mins thrashing]..... I fix that with a new condenser [its 6 volt, points and kick start]. now it will run flat out and get hot with no problems.
so having invested a whole £25 on it, I know it is a runner and also a keeper as it reminds me what it was like being 16 and going everywhere at full throttle
so the big investments now..........
2 new tyres and run it for a year doing errands and summer day pootleing etc.
Then last year I get hold of a +0.5 oversize piston and it gets a rebore.
and now I manage to get a NOS Micron expansion pipe.
so the plan now is to keep modding it like every 17yr old did in the early 80s and make it into a boy racer tribute
so the photo history from when I found it the 2nd time.
Once I got it running
sitting in the sun with the rest of my girls
last night with new pipe
A cut and paste image of where I want it to head
Anyway, it then sat in my shed till one of my mates asked to buy it to pass his test on, and I told him he couldn't buy it, but he could use it and give it back to me when he was done with it. he passed his test and then passed the bike on to someone else under the same rules, they MOT'd and taxed it and passed it on a total of 4 times, by which time we had all forgotten about it
so roll on 14yrs and I am reminded about the bike when a friend is looking for a commuter bike for her son, so the search starts and after a few weeks it is tracked down to somebody's granny's garage, where it is hiding under a blanket........ 7000miles on the clock and only a bit of surface rust on the chrome......... now it is a classic I am interested again.
I get it home and clean the carb, throw out the airfilter as the foam is crumbling, and I get it started. Ride it about 2 miles and it starts to splitter and it dies
, and I need to get towed home........... turns out all the crank seals were perished and I had lost all the crank case compression to suck the new charge in from the carb, then up to the combustion chamber.I tell our fried that it will take too long / cost too much to fix and tell her son to look else where, but in truth I didn't what a 17yr old thrashing this old family airloom .... it needs cherishing and looking after in its retirement.
get gasket set and new bottom end brgs and crank seals from China for about £20 and strip it down................ a 1970's air cooled 2 stroke single is about the simplest thing in the world and its done in a few nights... only need to remember the impact driver for all the "soft as feck" Philips head screws that they used back then. Piston has seen a few seizures, but I clean it up just to make sure it is a runner.
result...... it runs, but when it gets very hot it starts to cut out [after about 10 mins thrashing]..... I fix that with a new condenser [its 6 volt, points and kick start]. now it will run flat out and get hot with no problems.
so having invested a whole £25 on it, I know it is a runner and also a keeper as it reminds me what it was like being 16 and going everywhere at full throttle
so the big investments now..........
2 new tyres
and run it for a year doing errands and summer day pootleing etc.Then last year I get hold of a +0.5 oversize piston and it gets a rebore.
and now I manage to get a NOS Micron expansion pipe.
so the plan now is to keep modding it like every 17yr old did in the early 80s and make it into a boy racer tribute
so the photo history from when I found it the 2nd time.
Once I got it running
sitting in the sun with the rest of my girls
last night with new pipe
A cut and paste image of where I want it to head
