installed bbk and now it won't start

[shakerdriver]

ok well i'm dumbfounded on this one. :banghead: my rally was running just fine before i took it apart to install the bbk. put it on, no problems of any kind. and now it won't start unless i've got it at wot, and even then its not really running. its just kinda chugging, as soon as i let go of the throttle it :censored: dies; if i plug the exhaust with my finger it :swear: dies. i had no adjustment for the oilpump, like the one in gt's how-to, that i could find anyway. i pulled the plug and its wet but i didn't mess with the carb so i'm totally confused on this one. :help: any ideas will be greatly appreciated. thank you.

[Reign]

If you didn't mess with the carb, it's probably running way too lean. The stock jets in most of these scooters are under 70. I've seen some as low as 50. To put that in comparison, I'm running a 87 right now, and it's still a bit lean.

[shakerdriver]

well now i really feel like a dumb :censored: . aparently while i was moving things around to get the shroud off i must've somehow disconnected the vacuum line that goes from the pitcock to the intake. :doh: i took everything back apart and when i took the shroud cover off the vacuum line dropped right in front of my face. i hooked it back up and put everything back together and it fired right up. now i just gotta wait till tomorrow to take it for a ride and see if theres a difference in it. but thanks for the reply Reign.

[2strokd]

Ah man, dang it :rant: !
Im glad ya figured it out tho :cheers: !
Im sure you will be happy with the extra torque from the
BBK :thumb:

[shakerdriver]

i've got a ? for anyone that can help me out here. i'm putting the polini bbk on my rally. i thought i would check the jet size on my carb, but when i open the bowl its got 2 jets sitting side by side, one little one and one tiny one. the bigger of the two reads 62 on it but the tiny has nothing on it. also i did figure out its a dellorto PHBN, but i can't find out any info about it at all. the opening that goes into the intake reads 19.03mm inside diameter. i went to dellorto's website and still can't find any info on it. any ideas? i believe it takes 6mm jets, if you measure the outside diameter of the jet on the threads.

[90GTVert]

www.thisoldtractor.com/gtbender/dellorto_parts_diagrams.htm
www.minimotogarage.com/phbn_setup.html

[shakerdriver]

well i got the polini bbk on the ole rally an DAMN what a difference it made. i also upjetted the carb from a 62 to a 80. now i need to tune the cvt and carb a little more but i'm pretty happy with the results so far. :riding: it was a little cold (38*) when i took it out for a quick ride but i didn't care. i was to happy with the results to pay attention to the temps. i also got the air scoop for the fan shroud done today. i'll post some pics hopefully tomorrow of the shroud with the new scoop.

[shakerdriver]

its not up to skeedrs level yet but i'm workin on it. don't care if i can do wheelies or not as long as i can get skeedrs kinda power to the ground for take offs.

[2strokd]

We can do that :devil: !

Glad your happy with the lil Sport kit! They pack a good little punch and are plenty safe on the stock bottom end. Great for a DD :thumb:

[2strokd]

Ride it around for a few more miles and get that ex.port stained like i told you.
Then i can open up the exhaust port some for you. Makes a good difference in a
sport kit with a 23mm exhaust port after its port matched to your pipe.
We wont make it very big, just match it to the exhaust.
Then widen the port some in the cylinder and raise it a tad.
Sport kits are fun because they pack good low-end punch. You can go from that and work
on getting more mid and upper mid power.

[Thebatman]

if your like me and cant find any jets, drill em out yourself. i have taught myself that with my oem carb..(well zombie taught me ).. it's fairly easy to drill your own jets.. got a nice lil carb kit going, calipers, micro drill bits, micro files(torch tip cleaner) solder, washers.... if i can i know you can do it.... :lol:

[shakerdriver]

i've got a ? about the cvt belt. now i'm only the second owner of this rally, first owner bought it brand new and shes 65+. i doubt shes been out there wrenching on it, but when i opened the cvt cover it had a yamaha belt 3AA-17641-00 on it that was to short. so i have no idea what the traditional size (788x17x28 so to speak) belt is for this rally. i done alot of research, and according to everything i could find out (even from the aprilia forums and all) it calls for a 757x17x28 belt. so thats what i ordered and it seems like its to short also, it rides about 6-7mm down in the rear pully at its lowest gear and i've marked the vari with a sharpie and it rides the same 6-7mm from the top of the vari also. i've already tried a 788x17x28 and it was way to big(slipped real bad), but i found a 777x16.5x30 belt online but i'm not sure how compatible it would be with my rally, its the only size i could find between what i've got and what i know is to big. any guesses or ideas here because i'm stumped.

[90GTVert]

The 777x16.5x30 should be compatible. It would probably sink lower in the variator at rest (assuming the current belt isn't all the way down) but it may or may not wanna ride all the way up the variator. If the current belt won't fit all the way inside the vari at rest, leave the face off and put it all the way to the center. Then see if it still won't reach near the outside of the rear pulley.

[shakerdriver]

i've tried that and it doesn't get all the way to the outside of the rear pulley. when i put the vari face on it won't go all the waqy down in the vari groove either. my main concern about the 777x16.5x30 is the difference between the 28 and 30. not sure what that # actually represents.

[90GTVert]

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