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That’s what I would do Moto. Not sure if that’s the right money (sounds fair to me). I have to do the same to the frame on my WR.
Rocket’s a welder!
Too far away to help though.A good paint job on the frame will set the tone for the rest of the project as well.
For the amount I spent in new parts I may as well have bought a new bike
I’ve got a company in Sydney who will anodize my rims black for $80 though. Pretty good except I have to sand them down 
and then get them to South Sydney….doh!!Getting the good swingarm off the other bike is royal pain in the ass! I’m a bit stuck as to what to do with pistons, rings and bore sizes too
So I’ve been pondering the piston, rings and bore situation today and have ended up buying a manual for the bike so I can find out what the recommended ring gap and piston-bore clearance should be.
Measuring up what I have I could take one of the pistons and use it for the other motor, replace the rings with the correct size and have the motor bored to suit the 1mm o/s from factory.
Anyway, whilst checking the ring end gap I notice that guy the had the bike before me has obviously mis-treated it (this was evident from the state of it anyway) as the ring end gap was 6+mm!! It would have had phark all compression and ridden like a slug!
He had issues getting it started when I bought it. With this and the fact you can see light across the length of one whole reed petal I think this would explain it!
Below is comparo of another ring from the other motor. Still a used ring but see the difference in thickness and see how the thin one is ovalized too:
Seat cover came off today, looks like someone has had a million goes at putting the previous one(s) on as there is no end of rusty staples in it. I’ve probably got hepatitis now.
Frame and swingarm are ready for shot blast and paint. I had to get the angle grinder on the chain to get it, and subsequently the swingarm off.
Wheels are having the tyres removed at the bike shop (haha
) and I will pull the wheel down when I get them back. I then have to sand and tart up the rims ready and get them to Sydney for anodizing.Top triple clamp is sanded and primed, awaiting paint.
Some other bits have been given the acid dip treatment with varying levels of success. Carbie has now gone almost black and furry. Might need to add a new Mikuni to the shopping list.
I’ll replace bolts where I can with high tensile Supercheap auto jobbies, haven’t decided of I’ll go the SS ones or the standard ones. I don’t like the bronze colour of the stock bolts, what ever happened to BZP???
Sanding the tank down is nothing short of nightmare too.
Hopefully the manual tells me what the weight and quantity of fork oil I’ll need as well as the motor specs.
6mm is huge Moto :ohmy: You may have measured it the wrong way mate. You did measure it in the bore didn’t you? Use the piston to put it into the bore, square it with the piston about half an inch in. Maximum would be about 18 thousands of and inch I would have thought but your manual will have it mate.
I like this thread well done what a huge job. Am looking forward to it being finished will pull the 370 out when your going if you want to do some long track or short track VMX style
TB
Found this after I posted hope it helps it helps it’s Eric Gorr and you may have his stuff?
The best way to know if the rings are worn is to measure the ring end gap. Put the ring in the cylinder and use the piston to push it down about 1/2 inch from the top evenly spaced. Now use a feeler gauge to measure the width of the ring gap. Normally, the maximum gap is 0.018–0.025 inch.
Ring End Gap rule of thumb
Ring end gaps for conventional rings…General rules of thumb
top ring .0045″ to .0055″ per inch of bore diameter (example 4″ bore x .005″ = .020″ end gap.
Second ring .0055 to .0065″ per inch of bore diameter (example 4″ bore x .006″ + 0.024″ end gap.
Oil rings are a minimum of .007″ per inch of bore.
Total Seal top rings are fitted at .0075″ to .0085″ per inch of bore.
Cheers TB, I hadn’t seen those numbers but to be honest I didn’t bother looking as I have bought the service manual so I can stick to what it recommends.
I measured the ring gap exactly as you described about 20 mm in from the bottom and about 10mm down from the top (below the normal stopping point of the piston rings at TDC).
It was 6mm, no joke! I had the feeler guages out ready to measure the gap as well
I put the other ring in (the one pictured) and it’s too big. I expected it would be but was good to check my calcs/measurements.Using the rules of thumb above the min top ring end gap should be somewhere around 0.3mm and with the bottom ring at 0.35mm.
Anyone know a good engine mob on the Central Coast or Newcastle? I could just take it to a machone shop but would rather someone who knows what they’re doing.
Sweet, the new chain has just turned up, first of many parts! I’m off to order a new carby……….
Yeah but I bet your Briggs goes harder than the IT
Maybe, but I know it ate more oil than your IT thats a fact
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