Piston woes....
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Adam_Winstone
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^... yeah, a little too tight by the look of it!
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Adam_Winstone
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So, that bit in the manual that suggests no more than 34mph for 900 miles....?
Looks like it had a pretty nasty seize and dragged the alloy over the rings, which is standard seizure stuff and normally relates to insufficient running in, over advanced timing or weak jetting (may be the result of an air leak).
Don't forget that the running in period also serves as a testing period to check to see how the motor runs at all throttle positions. Did you mark up the throttle & housing and check at each position? Don't tell me that you trusted a pre-jetted carb?!
Regardless of why, I'm sorry to see that you've had troubles with it
Cheers Timbo.
Adam
Looks like it had a pretty nasty seize and dragged the alloy over the rings, which is standard seizure stuff and normally relates to insufficient running in, over advanced timing or weak jetting (may be the result of an air leak).
Don't forget that the running in period also serves as a testing period to check to see how the motor runs at all throttle positions. Did you mark up the throttle & housing and check at each position? Don't tell me that you trusted a pre-jetted carb?!
Regardless of why, I'm sorry to see that you've had troubles with it
Cheers Timbo.
Adam
I had a very similar situation on the way to the IOW. My ts1 had only ever been on single carriage ways up until that point. I fitted a long range tank, due to it being as thirsty as a Range Rover, and noticed a few particles of rust in the carb, so I fitted an inline fuel filter.
Bad mistake. After smearing the rings into the piston, just like yours, I did a rebuild and tested the fuel flow. With the filter on it was 350 ml per min, and with it off, it jumped up to 800 ml!
The scooter had been set-up by diablo on the dyno and ran great, but it was only on a dual carriage way, at constant throttle, that the fuel starvation became a problem. The float bowl was not filling fast enough.
I always check fuel flow now. It's a good job too, as my vespa has an SIP tap and it flowed 350 ml on reserve and 550 ml on the on position.
Bad mistake. After smearing the rings into the piston, just like yours, I did a rebuild and tested the fuel flow. With the filter on it was 350 ml per min, and with it off, it jumped up to 800 ml!
The scooter had been set-up by diablo on the dyno and ran great, but it was only on a dual carriage way, at constant throttle, that the fuel starvation became a problem. The float bowl was not filling fast enough.
I always check fuel flow now. It's a good job too, as my vespa has an SIP tap and it flowed 350 ml on reserve and 550 ml on the on position.
I don't want to keep up with modern traffic. I want to hoon past it, preferably on one wheel!
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Special X
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- Main scooter: Lambretta 125 special 230cc
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That piston can be saved if the ting grooves are ok. Clean it up, use coarse emery in a crosshatch pattern on the seized areas below the rings to retain oil on the high spots, have the barrel honed lightly.
Then rag the X7 needle out and throw it away (as they have a weak spot right in the area you seized up). Fit an X13 needle on the 1st clip and away you go. The hone will give you a better clearance so you'll just need to run the rings in for a few hundred miles, but don't be afraid to give it some throttle and high revs for short periods to get the rings to bed in.
Then rag the X7 needle out and throw it away (as they have a weak spot right in the area you seized up). Fit an X13 needle on the 1st clip and away you go. The hone will give you a better clearance so you'll just need to run the rings in for a few hundred miles, but don't be afraid to give it some throttle and high revs for short periods to get the rings to bed in.
So why had the Augusto caused this?...or do you mean an incorrectly set up agusto?