Jetting stock carb, need help please

Does your Spree/Elite already run great, and you're trying to make it quicker/faster? Need a monster motor swap? Discuss your ideas here.

Moderator: Moderator

Post Reply
User avatar
alexfleury
Spree
Spree
Posts: 133
Joined: Thu Aug 22, 2013 5:29 pm
Location: Hills of East Tennessee

Jetting stock carb, need help please

Post by alexfleury »

I have a de-restricted Elite 50, 2001. You can read about what I have done in the "Best Bang for the Buck" threads.

But it is a stock bike with the air box mod, an 85 main jet and a Keli variator. I just guessed at the main jet size based on my reading here.

I got a good deal on a Technigas exhaust and thought it would look good and maybe sound cool and ad a little performance. It does look cool !

Image

I found that the exhaust isn't much louder than stock, but sounds kinda raspier. Went for a test ride and founf very little in performance gain maybe a little lost midrange and gained a little top end.

But I got back from a 5 mile ride and checked the temp gauge.

Image

I was watching the gauge and kept the temps mostly in the 380 range for most of the ride. I know that is still too hot! Will a fairly quiet pipe that doesn't run much different than a stocker cause that much increase in head temps?

I guess my first idea was to question the accuracy of the temp gauge. I could put the stock pipe back on and check everything again. But I'll bet that would be a wasted exercise. Assuming that the gauge is correct, what main jet should I try? I think an 85 is already larger than a stock 50 Elite. But I think the Big Bore guys are with bigger carbs are only running something like 105 to 115 mains. Should I try a 90 or a 95? That seems like a big jump for a stock motor and carb, but I know there are people here who know much more about this than I do.

And any help will be much appreciated !!

Alex
Life May Not Be
The Party We Wished For
But While We Are Here
We Might As Well
Dance
User avatar
tazland001
Board Supporter
Board Supporter
Posts: 1333
Joined: Thu Apr 30, 2009 11:46 pm

Re: Jetting stock carb, need help please

Post by tazland001 »

I would start with a 90 main with a free flow filter. Make sure to do plug chops.

The reason your pipe lost lows and mids is because you are running the stock 39mm cylinder and there is not enough HP to run that muffler in my opinion. If you had a 47mm-50mm BBK you would notice a big difference.

Taz
User avatar
alexfleury
Spree
Spree
Posts: 133
Joined: Thu Aug 22, 2013 5:29 pm
Location: Hills of East Tennessee

Re: Jetting stock carb, need help please

Post by alexfleury »

Thanks guys. I just bought another bike with a BBK so maybe this pipe will end up on that bike. The BBK bike has a V8 which I'm assuming is also too much pipe for a stock bore. Plus the V8 is a bit loud for an around town errand type bike, but d*** the BBK bike does run ! I'm guessing it has about double the HP of my stock bike. :-)


I'll try a 90 and run it again. I just got the head temp gauge and right now I'm just guessing on the jetting, but when I get the temps in the 350 range I'll see how the bike runs then.

Thanks for the help!
Life May Not Be
The Party We Wished For
But While We Are Here
We Might As Well
Dance
User avatar
Wheelman-111
Moderator
Moderator
Posts: 11325
Joined: Wed Oct 22, 2008 5:09 pm
Location: Deepinnaharta, Texas

Re: Jetting stock carb, need help please

Post by Wheelman-111 »

Greetings:

Honda-san makes an 88 - Part number 99101-something-0880. I'm thinking that might just be enough.
Wheelman-111
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
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
Post Reply