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ET2 70cc upgrade Low Compression
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dmshar5
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dmshar5
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Have a 2003 Vespa ET2 with 670 miles on it, just installed a Malossi
70cc iron BBK. Checked compression, only 25PSI! WTF! All new gaskets, new Malossi reeds. Compression check with WOT. At a total loss for what's wrong, any ideas/suggestions? TIA.
Landy89
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Landy89
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valves are not set properly.
Tierney
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Tierney
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Did you check the end gap on the rings?
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Motovista
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Motovista
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Does the arrow on the piston point down?
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dmshar5
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dmshar5
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Finally, found out my compression gauge was faulty. When I tested it on my brand new Buddy 125, it gave me the same reading as my rebuilt ET2 70cc. That's what you get with a Chinese compression gauge, in fairness I just got a faulty one. Anyway problem solved and scooter is running just fine, started right up on first push of starter button, just had to adjust idle. I am waiting on a main jet kit, present jet is 65, want to start at 90 and work backwards. Others have said an 80-85 main jet seems to work well with a 70cc iron BBK with Leo Vince Touring exhaust, with restrictor removed. Next move will be a new Malossi variator, with Malossi belt and 7.2 gram Malossi rollers. Any other suggestions, greatly appreciated. Cheers!
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PeterCC
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Piaggio Beverly 300 ie - 2012
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PeterCC
Molto Verboso
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Piaggio Beverly 300 ie - 2012
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Location: Belgium
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dmshar5 wrote:
Finally, found out my compression gauge was faulty. When I tested it on my brand new Buddy 125, it gave me the same reading as my rebuilt ET2 70cc. That's what you get with a Chinese compression gauge, in fairness I just got a faulty one.
(...)
Good to share your finding.

Do not trust blindly measuring tools.
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