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View Full Version : New BBK Installed, now what?


tatjim58
04-29-2013, 08:32 AM
Went from 49 to 70cc. After running it HARD, soft seize. It started back up and made it home. I have Bel-Ray semi-synth 2T in the scoot now. Should I be using a different oil during break-in??? :shrug:

teddy554
04-29-2013, 08:47 AM
No you need to go bigger on your main jet most likely are you using the stock oil pump if so you need to adjust it to allow some more oil in the mixture but what size jet are you using stock airbox or open air filter stock pipe or aftermarket ?

techie610
04-29-2013, 11:32 AM
Bigger jets, air, exhust.
2T needs the back pressure in the exhust to keep the reeds in check.
I run the TechniGas RS.

In time, I would highly recommend going to carbon fiber reeds, and bigger valves, if you have not already.

50cc
04-29-2013, 11:58 AM
Sorry to interrupt, but do you really have to downjet when you switch to carbon reeds?

teddy554
04-29-2013, 12:15 PM
Sorry to interrupt, but do you really have to downjet when you switch to carbon reeds?
Never heard of down jetting for carbon reeds the reeds should have no effect on your fuel air mixture, but you do need to upjet for a expansion pipe, I have done many bbk with the stock pipes and had no issues of seizing with the stock pipe if jetted right. The main cause of soft seizing is not enough fuel or oil and fuel being the issue 90% of the time cause the motor to run too hot. 2t compared to 4t are a lot more touchy where you need to be real close to the correct air fuel mixture in combustion for it to run right.

tatjim58
04-29-2013, 05:49 PM
Thanks for the input. The exhaust is a Leo Vince Handmade 70. Everything else is stock. The scooter is a Benelli Andretti M50(QJ). What jets should be changed and to what size? It also run like shit at 1/4 throttle. Would 4 gram rollers be better. Not worried about top speed. Just want this bugger to run smoother. Thanks Gents!

BTW Teddy, the scooter came stock with a touring pipe(looks big enough to me to be an expansion pipe).

I should probably also take a look at the plug.:hmm:

techie610
04-29-2013, 06:05 PM
What size rollers came with it?
Probably needs a No-Rev Limit CDI.
As Teddy said, might look into more air intake. Bigger jug needs more breathing.

teddy554
04-29-2013, 09:07 PM
Thanks for the input. The exhaust is a Leo Vince Handmade 70. Everything else is stock. The scooter is a Benelli Andretti M50(QJ). What jets should be changed and to what size? It also run like shit at 1/4 throttle. Would 4 gram rollers be better. Not worried about top speed. Just want this bugger to run smoother. Thanks Gents!

BTW Teddy, the scooter came stock with a touring pipe(looks big enough to me to be an expansion pipe).

I should probably also take a look at the plug.:hmm:
With what you have i would say 90-95 main would put where you need to be, and yes check the plug i seen them melt away from running to hot but if you put the pipe and bbk and never upjetted i would not ride it at all untill you up jet you will run the bbk you just installed watch this videos in this link it will break the carb down for http://49ccscoot.proboards.com/thread/4212/videos-minarelli-carburetor-setting-adjustment and some good carb reading http://49ccscoot.proboards.com/thread/364/jet-info-stock-carbs-minarelli