94 Sa50p Malossi BBK Install- Carb questions

Trying to get your Spree/Elite to run, or run better? Post your questions here.

Moderator: Moderator

Post Reply
nhscooterguy
Noob
Noob
Posts: 7
Joined: Tue Aug 18, 2020 3:21 pm

94 Sa50p Malossi BBK Install- Carb questions

Post by nhscooterguy » Tue Aug 18, 2020 3:41 pm

Hi Everyone,

I've been driving my '94 Elite SA50p (Af16) for about 5 years now. After about 2k miles of driving this summer, I've finally blown the piston. Will an aftermarket exhaust on a stock engine cause the rings to blow? It happened about a 30 miles after replacing my broken exhaust with one like this:

https://www.ebay.com/itm/Racing-Exhaust ... 2351202737

I ordered the Malossi 70cc BBK and I'm waiting to receive it in the mail however, I've got a couple questions that I'm hoping someone here will help me with. I read through some older posts but I still didn't find exactly what I'm looking for.

First, with the installation of the BBK will I need to start premixing fuel to supplement the stock oil pump? I've had the oil pump propped open with a zip tie since I've owned it, not sure if this will suffice or if I should start adding oil to the gas.

Second, can I run a 70cc BBK with the stock carburetor?

I installed a BBK on my wife's Chinese Gy6 scooter but the gains were pretty much non-existent until I swapped the CDI and Carburetor out. Elite's have more pep than the Chinese scooters so I wasn't sure if I could get away with a stock carb.


Sorry for all the newb questions. Thank you for your help!

User avatar
bonesv
Moderator
Moderator
Posts: 1998
Joined: Sun Jun 26, 2011 2:00 pm
Location: Florida

Re: 94 Sa50p Malossi BBK Install- Carb questions

Post by bonesv » Tue Aug 18, 2020 4:26 pm

Do you have/use a cht gauge to monitor cylinder head temps? This is a must-have item and anytime you change to a different exhaust pipe you most likely will need to adjust the jetting.
Honda Elite SR
Honda Elite-Dio ZX

Dio ZX Headlight/Disc Brake Mod: http://hondaspree.net/phpBB3/viewtopic.php?t=30861

User avatar
Wheelman-111
Moderator
Moderator
Posts: 11139
Joined: Wed Oct 22, 2008 5:09 pm
Location: Deepinnaharta, Texas

Re: 94 Sa50p Malossi BBK Install- Carb questions

Post by Wheelman-111 » Tue Aug 18, 2020 4:36 pm

Greetings:

You absolutely can run a BBK with stock exhaust, carb, airbox. The gain in performance will be substantial, unlike your experience with the GY6. Mine worked best with a 90 main. 92 and it 4-strokes badly and falls flat on its face at WOT. See specs. With 9:1 gears - no others need apply -you should see 55 MPH all day long. See Flash 9 specs.
Wheelman-111
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 72MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH

nhscooterguy
Noob
Noob
Posts: 7
Joined: Tue Aug 18, 2020 3:21 pm

Re: 94 Sa50p Malossi BBK Install- Carb questions

Post by nhscooterguy » Tue Aug 18, 2020 4:43 pm

I don't have a cht guage however, I may consider one if it is best. Everything I've learned thus far has been on the fly so I am grateful for this site. It sounds like a jet upgrade is in order for sure. Any thoughts on the fuel mix?

Also, I don't own a press and from what I understand, to do the 9:1 gear swap I'll need one to remove the gear. Is that accurate?

Thank you for the quick replies!

User avatar
bonesv
Moderator
Moderator
Posts: 1998
Joined: Sun Jun 26, 2011 2:00 pm
Location: Florida

Re: 94 Sa50p Malossi BBK Install- Carb questions

Post by bonesv » Tue Aug 18, 2020 6:14 pm

nhscooterguy wrote:
Tue Aug 18, 2020 4:43 pm
I don't have a cht guage however, I may consider one if it is best. Everything I've learned thus far has been on the fly so I am grateful for this site. It sounds like a jet upgrade is in order for sure. Any thoughts on the fuel mix?

Also, I don't own a press and from what I understand, to do the 9:1 gear swap I'll need one to remove the gear. Is that accurate?

Thank you for the quick replies!
Yes, for secondary gears. You can get a machine shop or motorcycle repair shop to press the gear off and on. It's very easy with the right tools but do not attempt to use the hammer and punch method-it will damage the shaft for sure. Not sure what you are referring to as a fuel mix.?? Wheelman just gave you the jet sizes for a stock carburetor with a stock exhaust. Swap to a performance exhaust and you may have to up the jet size some more. This is where the cht gauge will let you know right away (hi temps) if you need to up jet or if there is a leak somewhere causing a lean condition and before you roast your new bbk!!! Use the forum for your questions. Use the advice given and use proper tools, use known methods and precautions, and you should be riding like you want to! Welcome and see you around! :thumbsup:
Honda Elite SR
Honda Elite-Dio ZX

Dio ZX Headlight/Disc Brake Mod: http://hondaspree.net/phpBB3/viewtopic.php?t=30861

nhscooterguy
Noob
Noob
Posts: 7
Joined: Tue Aug 18, 2020 3:21 pm

Re: 94 Sa50p Malossi BBK Install- Carb questions

Post by nhscooterguy » Thu Aug 20, 2020 4:47 pm

For the fuel mix I mean for gas and oil. Some of the posts I read say that the stock oil pump can't keep up with a 72cc big bore kit so I'm trying to figure out if I should be adding extra oil to the gas. I'm trying to keep the scooter as stock as possible but I do want to unlock a little more speed. Any recommendations for things I should install alongside the big bore kit would be greatly appreciated.

User avatar
bonesv
Moderator
Moderator
Posts: 1998
Joined: Sun Jun 26, 2011 2:00 pm
Location: Florida

Re: 94 Sa50p Malossi BBK Install- Carb questions

Post by bonesv » Thu Aug 20, 2020 10:27 pm

I add 1 oz. of 2 stroke oil per (mostly empty) tank (.75 gal.) of fuel on my sa50 elite w/72 cc (I also retained the stock sr oil pump) and that seems to be sufficient for proper 32:1 ratio
Some may say this is not a perfect method and it is not, I admit, because i don't always fuel up with exactly the same amount of room in my tank.
It's good so far for my scooter. (2600 miles). I keep a 5 oz. container of oil under the seat. It's real simple.
Honda Elite SR
Honda Elite-Dio ZX

Dio ZX Headlight/Disc Brake Mod: http://hondaspree.net/phpBB3/viewtopic.php?t=30861

nhscooterguy
Noob
Noob
Posts: 7
Joined: Tue Aug 18, 2020 3:21 pm

Re: 94 Sa50p Malossi BBK Install- Carb questions

Post by nhscooterguy » Mon Sep 28, 2020 12:19 pm

So this weekend I upgraded the stock jetting to a 100 and de-restricted the variator. It seems to be running somewhat ok but the bike dies out if I keep it over half throttle for more than like 10-15 seconds. It's almost like it is overheating and stalling. Any thoughts? Should I get a bigger carb?

Post Reply