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Si jetting rotary vs reed?
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MJRally
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MJRally
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It might have been discussed before but I'm not using the right search terms, but does anyone know ballpark how many points to adjust for a rotary motor vs reed with everything else being equal?
Jack221
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Jack221
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Reed will be richer but really depends on the details. Which reed block?
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MJRally
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Jack221 wrote:
Reed will be richer but really depends on the details. Which reed block?
Basic LML Stella reed block vs Piaggio rotary
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Wouldn't jetting be the same?

Cylinder/exhaust/timing hasn't changed…

Just the way the fuel and air is fed in is different.
Jack221
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Jack221
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MJRally wrote:
Basic LML Stella reed block vs Piaggio rotary
For a totally stock set up on both, the reeds have less blow back, so would be leaner jetted for the same everything on low throttle but richer overall jetting at higher rpm.
I would expect the Stella to be more economical than the Vespa and still be slightly quicker. Having almost no experience of totally stock set ups, this is just what I expect.
Once kitted this situation completely changes for both.
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MJRally
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MJRally
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Jack221 wrote:
Once kitted this situation completely changes for both.
Got any ballpark ideas for a middle of the road kit with a 24/24 carb and road 3.0? Just looking for a good place to start.
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chandlerman
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MJRally wrote:
Got any ballpark ideas for a middle of the road kit with a 24/24 carb and road 3.0? Just looking for a good place to start.
140AC/BE4/130MJ is where I'd start with that. It may be rich, but shouldn't be lean.
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MJRally
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MJRally
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So after some runs this morning, I'd say ballpark rotary uses 5-7 points LESS than the equivalent reed setup.
Jack221
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PX221 MHR heavily tuned, PX200 O tuned, PX181 M1XL tuned, PX166 tuned a quite bit and some motorbikes
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Location: London UK
 
Jack221
Jet Eye Master
PX221 MHR heavily tuned, PX200 O tuned, PX181 M1XL tuned, PX166 tuned a quite bit and some motorbikes
Joined: UTC
Posts: 5192
Location: London UK
UTC quote
MJRally wrote:
Got any ballpark ideas for a middle of the road kit with a 24/24 carb and road 3.0? Just looking for a good place to start.
I'd go with AC120/BE3/135 and 55/120
Main jet is hopefully too big and will reduce.
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