The 50

**F5 Dave** · 22nd January 2016, 17:15

That's a good start for av. I'm about 15.6

**cotswold** · 22nd January 2016, 17:38

Originally Posted by richban

Nice one. I will be there soon. I have just been in the shed with the grinder and diamond files putting a nice radius on the transfer ducts and boost port. What comp is that. I was thinking of going 15:1.

fourteen point one

**richban** · 22nd January 2016, 19:24

Originally Posted by cotswold

fourteen point one

Are you on the fence? What fuel are you going to run? Seams Hi for pump and not enough for Av. I think!

**F5 Dave** · 22nd January 2016, 20:03

That's still rral safe for pump. Even 15 would be fine for lc 50 on pump. I could easily run more but at some point you juggle the comprise of stinger and spark lead vs compression.

**cotswold** · 22nd January 2016, 22:12

Originally Posted by richban

Are you on the fence? What fuel are you going to run? Seams Hi for pump and not enough for Av. I think!

half and half

**F5 Dave** · 23rd January 2016, 06:21

Back in the day of leaded pump gas I used to run 17:1

That gas was good. Better than AV for power production and despite many experiments of com and shape, jetting and ign I never matched it with same spec below.

**mr bucketracer** · 23rd January 2016, 06:58

Originally Posted by cotswold

half and half

thats what i like running ,all my 2 strokes i run at 14 to 1 like all the fast 50s of the 60s and 70s

**kel** · 23rd January 2016, 09:16

Originally Posted by cotswold

half and half

You now have 2 fuels with different burn properties mixed together. Leaded which likes to run lean with lots of comp and advance, Unleaded which likes to run rich with considerably less comp and advance. That's kind of like a Shandy for your motor
(just in case; Shandy = beer+lemonade,

)

Plus the head insert is for 98 -

Originally Posted by cotswold

Mark just got back to me and it's 98 for this design so all good

**mr bucketracer** · 23rd January 2016, 10:16

Originally Posted by kel

You now have 2 fuels with different burn properties mixed together. Leaded which likes to run lean with lots of comp and advance, Unleaded which likes to run rich with considerably less comp and advance. That's kind of like a Shandy for your motor
(just in case; Shandy = beer+lemonade,

)

Plus the head insert is for 98 -

with there powers combined we have captain planet

**richban** · 23rd January 2016, 10:33

Originally Posted by mr bucketracer

with there powers combined we have captain planet

Ha ha.

Which setup makes the most toque sooner in the rev range yah reckon? Lower comp pump gas or mega hi comp Av gas. We are fat kart track racers after all. Corner exit is everything.

**kel** · 23rd January 2016, 11:06

Originally Posted by richban

Which setup makes the most toque sooner in the rev range yah reckon? Lower comp pump gas or mega hi comp Av gas. We are fat kart track racers after all. Corner exit is everything.

With unleaded you will lose some mid (at the same rpm) but it can give you a wider power band, more revs, and more hp. A 50's kart track corner exit speed would be all about clutch slipping out of corners, lower rev torque is less important than keeping on the pipe therefore unleaded wins.

**richban** · 23rd January 2016, 11:38

Originally Posted by kel

With unleaded you will lose some mid (at the same rpm) but it can give you a wider power band, more revs, and more hp. A 50's kart track corner exit speed would be all about clutch slipping out of corners, lower rev torque is less important than keeping on the pipe therefore unleaded wins.

Hummm. Well after riding my stock 50 at kaitoki the only time I needed to slip the clutch was when I messed up a gear change. A quick shifter is sitting in the box ready. Got to worth its weight in gold on a 50. It was a game changer for me on the 300.