I had the same trouble on a cast iron bore till i got cylinder honed at my local ( old school ) engine shop, then ragged all over , on decent oil i might add, feck this mineral crap, bloody northereners trying to save a shilling , goldeneyeDiablo wrote:I don't think you can beat having the bore taken to a decent old school engine reconditioners for a precision hone. I don't fit any barrels untill they've been to cylinder rebores in Nuneaton. It greatly reduces running in time as well.
Two miles and it died
- bazman
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that was Rockoil in me gearbox cheeky get
spider snapped a bit off, thats what done me. should have took them plates off ya and put them in me spares box (got four sets this year with that ruse) SHHHH!

- bazman
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goldeneye wrote:that was Rockoil in me gearbox cheeky getspider snapped a bit off, thats what done me. should have took them plates off ya and put them in me spares box (got four sets this year with that ruse) SHHHH!
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What's the saying ...if you fell in the river you'd come out with 2 salmon in ya pockets lol!!
Listen to the wise words of yer Uncle Al ..why spend all that time and money and then go and bolt an unknown top end on? Take the top end off, see whats happened and get it checked over.Diablo wrote:I don't think you can beat having the bore taken to a decent old school engine reconditioners for a precision hone. I don't fit any barrels untill they've been to cylinder rebores in Nuneaton. It greatly reduces running in time as well.
Also when running in, try not to "load" the engine too much, use the gearbox more than you normally would and don't hold the throttle at the same point for too long, just in case a part of your jetting is lean. Every so often, nice short sharp bursts of speed are fine...Its all about putting the engine under increasingly hotter heat cycles. With the correct piston / bore tolerance you'll be fine.
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Hotspur
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Thanks for the advice all. I've taken it apart now, and it's got two sieze marks on the piston and in the bore. The rings needed a bit of "help" to get off the piston. So to my next question, will a cylinder hone, a clean of the piston with a bit of wet & dry, and a new set of rings be OK, or is it off for a rebore and new piston. The bore is barely feelable with a finger nail, and the piston is much the same.
Cheers Pete
Cheers Pete
a pic would help us judge better what is required ...cleaning up wise try avoid wet/dry ..or any sand paper type product as you dont want that grit left behind...better to carfully scrape any high spots
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Hotspur
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Thanks for the tips Ricspeed, but I fear they've come too late. Went out in the garage last night, used a gasket scraper followed by 1200 grit on the piston with a little oil, then pollished it on a buff with just T cut. I can see, but not feel any marks on it. As for the barrel, used my (frowned upon by some) trusty sprung three legged honer on slow in a cordless drill. Again I can see a few marks, but can't feel any. So now for the price of a set of piston rings and a few gaskets I'm gonna try it. One last question though. How do I measure piston to barrel clearance, and what gap should I set the rings at ?
Thanks again folks
Pete
Thanks again folks
Pete
give it a good wash off with parrafin or sommat
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