Scooterotica

hi all,
has anyone been using this kit for a wee while on their carb yet? and if so what are the results?
thank you

Are power jets over kill on slow revving (8000rpm) scooter engines, i thought they were for screaming (15000rpm) 125cc racers.

A power jet is not just for high revving engines, it can give some of the following:
Prevent lean spots through the rev range
Give you more BHP
Good for different altitudes
Improve your fuel efficiency

I have got one, just haven't got round to fitting yet.

I’ve been using a PHBH 30mm Cam lam power jet on my TS1 for the last few months (previously 34mm delly)

With the 34mm delly I had to have it set up quite rich to keep the temps down (egt)

With the 30mm power jet I have a crisp throttle, a much better ride and good engine temps, and I am using 30% less fuel...very happy with it....sits in the fast lane all day long.

The main use for a powerjet on scoots in my opinion is to be able to keep the mid range rich enough while still letting the bike have enough fuel at full throttle.
I found by using my egt on my Monza kitted GP (and by taking advice from experienced tuners) that the high egt temps were at just under 1/2 throttle after rolling off from full throttle. The temps would remain dangerously high and not come down at this point.
The only way this could be cured was by running an X2 needle in an AV266 atomiser but this caused the bike to splutter like hell at low revs. To cure this you could come down on the main but this then left it slightly too lean for constant full throttle running.
The power jet cured this by letting me come down on the main jet so i could use a rich needle/atomiser combo but then fed the engine extra juice from 1/2 throttle up so i was safe for full throttle running as well.

lockman69 wrote:I’ve been using a PHBH 30mm Cam lam power jet on my TS1 for the last few months (previously 34mm delly)

With the 34mm delly I had to have it set up quite rich to keep the temps down (egt)

With the 30mm power jet I have a crisp throttle, a much better ride and good engine temps, and I am using 30% less fuel...very happy with it....sits in the fast lane all day long.

do you mind me asking what jetting you using?
cheers
mick

nelson pk wrote:The main use for a powerjet on scoots in my opinion is to be able to keep the mid range rich enough while still letting the bike have enough fuel at full throttle.
I found by using my egt on my Monza kitted GP (and by taking advice from experienced tuners) that the high egt temps were at just under 1/2 throttle after rolling off from full throttle. The temps would remain dangerously high and not come down at this point.
The only way this could be cured was by running an X2 needle in an AV266 atomiser but this caused the bike to splutter like hell at low revs. To cure this you could come down on the main but this then left it slightly too lean for constant full throttle running.
The power jet cured this by letting me come down on the main jet so i could use a rich needle/atomiser combo but then fed the engine extra juice from 1/2 throttle up so i was safe for full throttle running as well.

interesting point
how does the main jet size affect atomiser/needle combo at low revs when it doesnt come in until 2/3 - 3/4 throttle?
ps are you using the AV266 with X2 needle - is i on top clip?

cheers
mick

The main jet has the biggest effect at 3/4 to full throttle but to say it has zero effect at 1/4 to 3/4 throttle is incorrect.
If you think about it the whole main system is fed via the main jet so reducing this size will have an effect on lower positions. Reducing your main jet size to clean up your mid range when you need to use bigger needle/ atomiser combos is quite a common trick but you do have to be very careful so as not to run dangerously lean at wide open throttle. I would never attempt this without some sort of gauge to let me know whats going on. If you think about it, which part of the jetting is more important to get rich and safe? Well thats answered by your riding style. do you spend most of your time cruising at half throttle and just under or do you ride everywhere at full throttle?
If you ride everywhere at full throttle make sure your main is a little rich and be careful when you throttle off. If you cruise at half throttle or under spend more time getting the needle/atomiser rich enough for this.
Just one other question to reinforce my point. How come most riders hole a piston or seize when cruising in the mid range?

The X2 is on the top clip by the way.
Pete

THANKS
am running my ts1 with x2 on top clip with 48mm clubman
just about runs clean through the rev range to main but i put a performance clubman on and it stutters at about 1/3 - 1/2 throttle when slowly opening up (main jet is big)

On me PTS1 Im running a CamLam PJ on a TMX30, (the std Mikuni one didn't work).
Set up by Diablo, the fueling is spot on through the full rev range.
Would recommend them. Easy to fit, easy to set up on dyno.