Had one of those SRs kits a while ago and I snapped the rings and scored the barrel so i had it took out to 66mm and it has just done the same thing again, after having plenty of miles on it already (a good 400 or so) ...
Could it be the crank not true or just cheap the cheap piston? (Goetz)
Eitherway im now rebuilding my top end again.
I havent got the funds for a good kit off the shelf so i was thinking of putting the following together after reading about old SR suzuki conversions, if anyone has any advice please let me know.
Hopefully i dont look too stupid with all this but im trying to learn as im going along. I understand i have to get the crank machined for the rod, any recommendations?
These are the parts (albeit a bit ebay i could source them elsewhere)
Kit :http://www.ebay.co.uk/itm/LAMBRETTA-SUN ... _945wt_907
Piston- http://www.ebay.co.uk:80/itm/Suzuki-TS1 ... 0706245975
Con rod- http://www.ebay.co.uk/itm/YAMAHA-RD400- ... _966wt_907
new SRs kit with suzuki piston etc.
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lammysilver
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coaster
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Has your existing barrel had the ports widened by any chance? That could account for the ring breakage if it has.
The piston you mentioned is only a replica Jap piston so the quality would highly questionable AND it has a window in the skirt which is designed to work with a reed valve.
I'd be inclined to have your crank checked out to see if it really is out of true and if it's ok then just use the piston in the kit but check the piston to bore clearance is not less than 3.5 thou and gap the rings to the bore.
The piston you mentioned is only a replica Jap piston so the quality would highly questionable AND it has a window in the skirt which is designed to work with a reed valve.
I'd be inclined to have your crank checked out to see if it really is out of true and if it's ok then just use the piston in the kit but check the piston to bore clearance is not less than 3.5 thou and gap the rings to the bore.
The piston shown in the link states generic picture, so it might not the one you'd be sent anyway. You could give them a ring and tell them what you need, as in non reed induction and see what they've got.
But don't you want a 1st oversize 66.5mm piston? I had a 185 taken out to 65.5 with a Wiseco and this was nearly the limit for this model piston. I think Mitaka stop at 65mm?
Doesn't say what brand it is, but Mitaka are from Taiwan and they're decent, if you call the shop you can find out what brand too.
I have 2 190's at the mo - one is virtually same as you are after. Indian GP webs with RD400 115mm rod, proper SR190 barrel with Mitaka piston in...never been run yet as piston dome protudes into ports at BDC, maybe just an issue only with mine as other people recommend this set up if you want to keep the full height barrel. Crank cost me £145.00 pressed while I waited and checked for true at Chiselspeed. Price may have changed as it was nearly 2 years ago. The word is Indian webs are better than Italian for this rod conversion.
The other 190 is using TV barrel with TV length con rod 116mm this is very smooth and a lovely ride, I've had shortened 190's before and they were really razzy. I prefer the longer barrel. Others maybe able to advise you better about whether topping and tailing the barrel is option.
There's quite a lot of 66.5mm Moto-x pistons on Ebay...if that is the mm you need.
But don't you want a 1st oversize 66.5mm piston? I had a 185 taken out to 65.5 with a Wiseco and this was nearly the limit for this model piston. I think Mitaka stop at 65mm?
Doesn't say what brand it is, but Mitaka are from Taiwan and they're decent, if you call the shop you can find out what brand too.
I have 2 190's at the mo - one is virtually same as you are after. Indian GP webs with RD400 115mm rod, proper SR190 barrel with Mitaka piston in...never been run yet as piston dome protudes into ports at BDC, maybe just an issue only with mine as other people recommend this set up if you want to keep the full height barrel. Crank cost me £145.00 pressed while I waited and checked for true at Chiselspeed. Price may have changed as it was nearly 2 years ago. The word is Indian webs are better than Italian for this rod conversion.
The other 190 is using TV barrel with TV length con rod 116mm this is very smooth and a lovely ride, I've had shortened 190's before and they were really razzy. I prefer the longer barrel. Others maybe able to advise you better about whether topping and tailing the barrel is option.
There's quite a lot of 66.5mm Moto-x pistons on Ebay...if that is the mm you need.
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lammysilver
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Cheers coaster, i will indeed check the quality and the suitability of the piston before i purchase anything.
And yes im sure the ports were widened slightly, so this may well account for the 'ring snapping' (not prison slang).
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mawso-
I mentioned the barrel i currently have is at 66mm and its a bit thin, so i may end up getting a 64mm barrel to start again.
Ive got a mec crank on it at the mo, ill check to see how much it costs to get sorted.
Your set ups sound like what ive been reading about and what im aiming for, ill look into it all further tmoro when i get a minute to work on it.
Any more info on 'topping and tailing' the barrel would be great.
And yes im sure the ports were widened slightly, so this may well account for the 'ring snapping' (not prison slang).
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mawso-
I mentioned the barrel i currently have is at 66mm and its a bit thin, so i may end up getting a 64mm barrel to start again.
Ive got a mec crank on it at the mo, ill check to see how much it costs to get sorted.
Your set ups sound like what ive been reading about and what im aiming for, ill look into it all further tmoro when i get a minute to work on it.
Any more info on 'topping and tailing' the barrel would be great.