It's alive! My 48mm taz kit roars to life.

[Spreetard]

Steady hands and carbide dremel bits make fun scooters Though as a baseline for BBK results, it's slightly bias. This build is not just a parts swap. The dimentions of the exhaust port have been changed, not only at the exit point of the jug, but also the size and shape of the port window.



Not that it's crazy race porting or anything, but it is slightly raised and widened. And before you ask, nope. I have no measurement of how much. I had an hour and a half to work on it. It got an hour and a half worth of port work.
That's an hour and a half of my life I'll never get back

Just you wait till I get one for myself I give it 6 hours of tweaking till I'm totally happy with it.
Now that 'yall have big bore kits you can finally keep up with my stock bore (Actually, Bobby's 44mm walked me the other day, but if i stay in his draft, ol' red will hang. Time to re-port the 41mm )

[tazland001]

When are you going to ride it?? I cannot wait to hear the results. I have to get my secondary gear for the elite e lathed to fit into the housing bearing. the elite e and the spree rear ends are slightly different and require just a small amount of machine work(lathe) on the secondary gear of the 15*81 gear set.. But it will fit like a glove when I am done. So I guess I ran into snag. So please test your spree sooooon. hehe

Taz

[vette66_00]

Yah no Doubt get to riding it and give us a report.... I'm waiting on parts should hopefully be here tomorrow and then Ill be installing.

[losthope]

I was told once that the exhaust port should be the same size at both ends. (opening at piston and opening at exhaust)

Anyone know if thats true?

[Wheelman-111]

Greetings:

The oval-shaped exhaust port window can't have the same shape as the round exhaust outlet. If the assertion was that the two should measure the same area, maybe that's true. However concentric tunnels cause the pressure waves to behave in unpredictable ways, good and bad. This leads to the Black Art of exhaust and port tuning... Try it and see?

[ae86guy]

updates please i want to know how the 48bbk performs what other mods have been done

[john]

2nd that one too, just installed the 48bbk, but just ordered the gears, the bbk says light riding for 2 -3 weeks according to taz's sheet for break in, so idk how soon you'll hear

[Bear45-70]

I was told once that the exhaust port should be the same size at both ends. (opening at piston and opening at exhaust)

Anyone know if thats true?

For answers to your questions go to the link below and read what Jennings has to say about the black art of 2 stroke tuning, exhaust tuning included.

http://edj.net/2stroke/jennings/

[bakaracer]

I was told once that the exhaust port should be the same size at both ends. (opening at piston and opening at exhaust)

Anyone know if thats true?

No they can NOT be the same. if you make the port window the same as the exit of the exhaust port,you will loose alot of the power and no lowend and torque.your powerband will be so narrow to NO powerband,you won't be able to tune it.

[john]

anyone have carb tuning tips (like how far to turn the screw out) on the 48bbk with stock carb and upgraded jet ?


I believe stock carb with stock jet is 1 1/2 turns out

[Wheelman-111]

Greetings:

It'll need a bit more fuel to go with that big 48mm draw. I suggest you start with 1 turn out from lightly seated. If the idle slows too much, you can increase the idle speed with the throttle-stop screw. Unfortunately without a replaceable Pilot jet, the PA series carbs are limited on low-speed tuning.

[tazland001]

Anyone ride the 48mm kit yet????????????????????????????????

Taz

[Trafficjamz]

Anyone ride the 48mm kit yet????????????????????????????????

Taz

Mine is almost ready to ride at WOT for small amouts of time.

Stretch went 34 MPH before the 48mm kit. Having the bigger bore is not going to change that.

I'm sure it gets there alot quicker now

I'll go take it for 1/2mile a WOT ride and report back.

[Trafficjamz]

Well I rode it!

It goes 34mph!

Why would it go any faster than that?

WOT does not rocket the spree forward like I thought it would.

Instead it stumbles and sorta 4 strokes.....I guess the 100 jet is Too big

However at 1/2 throttle the spree picks up with lots of pep.

I'm sure once the jetting is corrected, this scooter will be very quick.

I have a 90 jet that I will try tomorrow. (I would like to try a 95, but I don't have one )

On a side note, the engine seems to have more vibration than before.

[mustangwagz]

On a side note, the engine seems to have more vibration than before.

i wandered about rotational vibrating mass...The spree innerds capable of handling all this new found alluminum its pushing?