kerker jetting

[Toolman]

Hey Guys,

I just bought a used Kerker 4-2-1 system with a 13" can that has a 1.5" outlet. This system will be used on a 87 Max.

What is the recommended jetting and needle clip position. I have stock needles (adjustable) or I could use factory pro.

I need good a starting point for

mains
pilot fuel
PAJ 1
PAJ 2

Please specify if jets are mikuni of dynojet

TIA
Dennis

 

[one2dmax]

mains - 150 all else stock. It will actually work well with the stock mains but be a bit rich.

Find one or buy one of the larger baffles. Helps flow and power (not to mention sound).

Sean

 

[Toolman]

Thanks Sean

one more question if you don't mind.

what jetting would I use with a Marks 4-2-1 ?

 

[one2dmax]

Same more then likely. Probably very similar jetting for about any header. Slip-ons would be different.

Sean

 

[lankeeyankee]

Hey Guys,

I just bought a used Kerker 4-2-1 system with a 13" can that has a 1.5" outlet. This system will be used on a 87 Max.

What is the recommended jetting and needle clip position. I have stock needles (adjustable) or I could use factory pro.

I need good a starting point for

mains
pilot fuel
PAJ 1
PAJ 2

Please specify if jets are mikuni of dynojet

TIA
Dennis

Dennis

Why not install your Kerker system first and than see how it does?
Check your plugs and gas mileage.
To be honest with ya, I dont think I would have installed a jet kit or even cracked my carbs when I first installed my Kerker years and years ago.
Unless you are going to dyno your bike or race it and get excited by numbers on paper I wouldnt mess with jetting unless you are having problems through the RPMS.
Once you start messing with your carbs and jets its a long road of tuning. Many hours of learning. Which isnt bad if you own tools, mechanically inclined than tear in to em, we are here to help if you dont mind the labor.
IMO Just install the kerker and go from there.
As Sean said get the 2.5 comp baffle, depending on your skills you can do what I did goto your autoparts store that sells exhaust pipe adapter / pipe in 18 in length and get a drilll and about 3 hours and start drilling holes in the pipe to make your own 2.5in baffle. Mcmaster Car also sells this amphorpis Silicone heat insulation which I use rather than fiberglass and the good thing is its a deeper sound and doesnt ever burn out. I know the 2.5 baffle from Kerker is over 100.00
I made mine for under 15 bucks.

 

[andrew5]

i have a kerker w/ 2.5" baffle,with stock jetting.when i put the header on,i syncned my stock carbs.runs and sounds great.

 

[lankeeyankee]

I have heard this before. I had a GSXR750 and installed a Vance&Hines full exhaust system and ran it without re jetting and it ran awesom if I remember it ran 124MPH in the 1/4 which was good for a 750 back in 90
Here comes my first expierence with a Suzuki Dealer. I decided Hmm why dont I spend more money and make it faster,, purchased a jet kit DJ STG1 and took it to the dealer to have them install it. (I was 18 and the bike was brand new)
Dropped it off and picked it up and damn it felt strong as hell on the ride home, took it to the track and only ran 119!:bang head: I was pist! to say the least, back to the dealer the following monday picked it a day later and took it back to the track this time running only 121:bang head: Back to the dealer again! Ok the 3rd time at the track went down to 118!!:bang head:
Thats when I started learning about Mikuni 36 Vac carbs! Never again have I let any dealer mech touch any of my bikes since that day on!!

I am not saying a jet kit wont increase your HP numbers. But if you just street ride chances are you wont notice a difference not worth the time invested in tuning., IMO