Jet kit - do I need one?

[Jimmy Hoffa]

Hey all - I'm going to be installing a Jardine 4-1 (thanks Mr. Jiggles) on my 1982 GS850G. Currently I have a 4-1 Kerker (which looks like absolute rusted crap, which is why I've never posted a photo of my GS) which I will be removing.

A bike mechanic in the area who will assist me tells me I need a jet kit to do this job. Is that correct? What, exactly is a jet kit anyway?

[coltrain]

If your bike is running alright with your current 4 into 1 pipe then I wouldn't see why you would need to rejet unless that old pipe of yours was junk. If bike is running good then my thinking is that the bike has already been jetted for a 4 into 1 hence you wouldn't need a jet kit. If you go to pods or open the intake up then you would need to rejet. 1st question we need to ask is how is the bike running and what do the plugs look like before and after installation.

[Jimmy Hoffa]

Well that's the thing - right now the bike runs kind of rough. It jolts a bit in the lower gears, and feels like it's not putting out as much power as it should. I just replaced the spark plugs, so they're brand new.

The guy from whom I bought the bike said that the person who had put on the 4-1 Kerker had never rejetted it for that bike. So I'm guessing then I do need a jet kit.

Dynojet sells a stage 3 kit for all GS850s. it's about $130 dollars, but on the website it reads **WARNING! ONLY TO BE USED ON RACING BIKES!!!** Is this something I should take seriously?

[coltrain]

do you have the stock air box on still?

[tkent02]

**WARNING! ONLY TO BE USED ON RACING BIKES!!!** Is this something I should take seriously?

Just legal mumbo-jumbo.
The jet kit will work wonders.
Get the kit number for your model and the proper stage kit for what intake you have.

[doctorgonzo]

Well that's the thing - right now the bike runs kind of rough. It jolts a bit in the lower gears, and feels like it's not putting out as much power as it should. I just replaced the spark plugs, so they're brand new.

The guy from whom I bought the bike said that the person who had put on the 4-1 Kerker had never rejetted it for that bike. So I'm guessing then I do need a jet kit.

Dynojet sells a stage 3 kit for all GS850s. it's about $130 dollars, but on the website it reads **WARNING! ONLY TO BE USED ON RACING BIKES!!!** Is this something I should take seriously?

Don't need a stage 3 unless you are doing pods. Exhaust only is a Stage 1 kit. They put the warning on for legal reasons because the jet kit may make it no longer meet emissions standards (but bikes aren't tested, so....)

[makenzie71]

you only need to rejet the bike if it doesn't work right.

[Jimmy Hoffa]

I have no idea if the stock airbox is still on it. My guess is yes.

Dynojet only sells a stage 3 for the GS850 - so I'll probably just buy that unless someone can point me in the direction of a Stage 1.

What are pods?

[doctorgonzo]

I have no idea if the stock airbox is still on it. My guess is yes.

Dynojet only sells a stage 3 for the GS850 - so I'll probably just buy that unless someone can point me in the direction of a Stage 1.

What are pods?

Individual air filters for each carb. The make the bike MUCH leaner, MUCH more effect on mix than exhaust. They require a major rejet. I think a stage 3 will make you too rich. You might be better off just raising the needles and bumping the main jet slightly with jets bought individually.

[Jimmy Hoffa]

So since the bike's not running right, and I'm changing the exhaust, I do need to re-jet, and a stage 3 jet kit will make the mix too rich. So I will call dynojet and see if they can put something together for me. Thanks guys. This website is a #@&%@ing GODSEND.

[doctorgonzo]

So since the bike's not running right, and I'm changing the exhaust, I do need to re-jet, and a stage 3 jet kit will make the mix too rich. So I will call dynojet and see if they can put something together for me. Thanks guys. This website is a #@&%@ing GODSEND.

If Dyno can't help, look at the carb specs thread, see what the stock main jet is, and get back with us. Z1 and others sell individual jets and you could just bump it one size and probably be close (hell I have some 115s lying around). The reason I think a stage 3 would be too rich, on my bike the Stage 3 kit takes the main jet from a 110 to a 155... Thats a LOT of fuel.