Mike the builder

Carb adjusted to 1 1/4 turns, works like a dream. Big thx to all that helped, I really appreciate it.

Thx so much for those tips, really helpful.

Thx peteff and I’ve seriously considered your approach adw, seriously.

Yes chinese carb, £18…. Will these adjustments affect starting ? No idea how to do those adjustments to be fair.

Pt2 tried again this morning, 12-15hrs later. 20+ pulls and quite a bit of engine trying and stopping, It’s starts and ticks over, revs ok. Bit jumpy on tickover. no idea if it will start again in a few hours though.

Next instalment, I want to cry. new, piston, rings, cylinder, spark plug, ht lead, ignition coil, stop start switch, complete carb and both filters. yeah it started ok, smoked well for first 30secs due to oil assembling. Left it ticking over for 30secs and stopped to go for dinner. now it won’t start again, plug wet, cleaned pug, starks well, compression still good. Changed fuel. doesn’t even seem to be trying, not even kicking back a bit. now I’m really stuck.

I’ve gauged the gap between the coil and the Manet using a piece of paper folded once. As for the kill switch, engine didn’t try to start with it connected and in run position, did try to start the kill switch gone. Can only be switch or wiring. Well for that fault.

I might yet swap the old carb back in to see what happens, but not 7ntilmthe switch is done.

Before anyone asks, I did disconnect the start stop right at the beginning of this project to check it wasn’t a problem

New plug, piston, rings and cylinder fitted. Also replaced all filters and carb. Fires up and starts briefly but I’m waiting a new start switch before I assemble it fully. I think the wiring or the switch is breaking down and shorting out after a few seconds. If I pull the unit over with plug out it sparks fior first couple of times I pull it over 5hen the spark stops, if I wait a few secs and try again it again sparks but only for first couple of pulls. Dis connect it totally and it fires up etc but with no covers on its tricky to keep it running. Look like we are on the home stretch now. Thx

Part 2. New piston and rings fitted to new cylinder. I now get compression with my (wrong) tester of 135psi. So that’s 30 psi better over several good pulls. just for fun I tested the old piston rings as described earlier and I get a gap of 13 thou top middle and bottom of the bore with both rings. Pretty consistent. 13 thou good ? ive noticed the new cylinder is harder to pull over although this is to be expected with 30psi improvement in compression ? the new rings are quite a lot stiffer and more tricky to fit to the new piston, again to be expected. I had a good look inside with a torch and couldn’t notice any worn out sections although it would be fair to say I’m not 100% what in looking for and I tried to get a gauge between the piston and the bore in several places and was unsuccessful.

I’m going to check that ring clearance. I’ve an old stihl hedge cutter and that’s harder to turn over than the cutter, I think this is the answer.

Thx, I’ve only one cutter. The new cylinder and piston will be here in a few days. Be interesting to see the psi difference. By ring gap do you mean the gap between the two ends.

Rings siting correctly in grooves. I’ll see if I can find some feeler gauges to test the rings. I have ordered new chinese cylinder, piston and rings and I’m going to check the compression when I fit those. I’m just interested to find out exactly what’s wrong regardless just for future. I’ll let you know how it goes, if yr interested of course.

Thx for advice, as you’ve guessed I’m a novice. I’ve some photos for fun. I found an Aluminium tube to use in tester instead of the rubber hose and I now understand the ration difference between small and large cylinder affects the volume of tester so I see the issue surrounding different pressure testers. That being said it’s what I have. With ali tube I’m now reading 105psi with oil added to the cylinder, I’ve taken it apart again and cleaned cyclinder, piston and rings, retested and still getting 105psi. I think I might of been barking up the wrong tree. pictures of tester, piston and inside of bore. Can even see reflection of my finger nail in one of them. time to order a chinese carb ? ( done carb kit already )