re-jetting help

[254]

Hi all, i have a 1982 gs750t, and have recently bought some k&n pods to go on. not especially for huge performance gain but more for looks. It has a 4 into 1 motad exhaust. The jets in the carbs at moment are 112.5 main and 42.5 pilot.
I realise that this question has probably been asked a 1000 times, but can anyone give info for re-jetting.
I have been told elsewhere to go as high as 145 on the mains and also elswhere to 120 on mains......... please help!!

 

[Steve]

Apparently you still have stock jetting, hope the engine is OK. :-k

General rule of thumb for a starting point is to go up two to four sizes on the mains for a header and three to five sizes for pods.
That would be somewhere in the range of five to nine sizes, depending on your bike.
You will to start with something between 125 and 135, but there is no way of knowing without trying.

An alternate method would be to contact Dynojet and ask for their Stage 3 kit for your bike.
It's a bunch of money, but usually gets the jetting spot on, first time.

.

 

[old_chopper]

I put pods and drag pipes on my 550. I didn't even mess with jetting it by trial and error, just bought the DJ stage 3 kit. It runs great, starts easy, no worries. Money well spent in my opinion.

 

[BassCliff]

Greetings and Salutations!!

Greetings and Salutations!!

Hi Mr. 254,

A lot of questions have been asked 1000 times so you can find the answers using the Search feature in the forum. To get you started, let me say "Howdy!" and extend a cordial greeting....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", the Carb Rebuild Series, and the Stator Papers. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

 

[Guest]

I'd start with 125 mains
45 pilot
Shim the jet needle by removing the stock spacer over the needle and replacing it with 1 or 2 washers. You can get the washers at radio shack.
OR
Just get a Dynojet kit

 

[Guest]

Hey Chef, wouldnt he also need to drill the slide?

 

[Guest]

Oh yeah
Drill the slide so the slides lift quicker to compensate for the extra air.
I'm not sure the drill bit size though. I always use the DJ bits.

 

[Guest]

Oh yeah
Drill the slide so the slides lift quicker to compensate for the extra air.
I'm not sure the drill bit size though. I always use the DJ bits.

Funny how those bits dont have a size on em ehh..

 

[Guest]

I could match the one I have.
Saltymonk knows the size if he hasn't forgotten.

 

[outlawfox13]

on my DJ 3 kit the slide drill says 30# HSS

 

[254]

thanks to all, i have not had bike long and have inspected carbs more, looks like the main air jet circuit has been tapped before.......not sure if this will be a problem fitting a stage 3. Have also come accross what i prosume to be the air correctors( packaging has L.E.D.A.R on it)..any ideas?