If you buy the "standard" jet kit sold by Dyna Jet and usually pushed by dealers when they sell a new set of pipes which is also the same kit most people buy on their own when they think they need one, then you are wasting your money. The number on the jet in the kit will be a larger number than the number of your stock jet, but the stock jet is a bigger jet.Not true. Both parts of your statement.
I myself have an open air filter with aftermarket pipes. The scar mod will only take you so far and that is a fact. The stock main jet 195 was not big enough for my setup. Plus the stock slow jet 55 wasnt giving me enough juice at low end. So depending what setup you are running, some of us need a jet kit. Apparently you don't know how to properly tune a carb then. Just sayin. There was no comparison with performance from the scar mod to the factory pro. Scar does make it run better, but not like it can. I am glad I spent the money on a jet kit, one of the best mods I have done for performance.If you buy the "standard" jet kit sold by Dyna Jet and usually pushed by dealers when they sell a new set of pipes which is also the same kit most people buy on their own when they think they need one, then you are wasting your money. The number on the jet in the kit will be a larger number than the number of your stock jet, but the stock jet is a bigger jet.
And if all that has been done is a factory exhaust mod or just the addition of pipes without increasing air flow, and just changing to a K&N filter does not count, then all that is needed is to adjust the A?F mixture out to a richer setting.
Adjust A/F, ride a hundred miles, check plugs, adjust again if fine tuning is needed and that is all.
Always turn A/F fully in, but not tight, and adjust out starting at two turns and you should not have to go more than 2 1/4 to 2 1/2 turns out total.
And I will add this... Even if you add big free breathing pipes and increase the air flow, you still do not need a jet kit. Do the SCAR mod to the stock jet and adjust the A/F. Youstill do not need a aftermarket jet kit.
But it is your money and time if you want to waste it on jet kits.
No, it isn't. I use to think that too, but I have measured them and the DJ 195 has a larger bore than the Keihin 195.If you buy the "standard" jet kit sold by Dyna Jet a...The number on the jet in the kit will be a larger number than the number of your stock jet, but the stock jet is a bigger jet.
My replies in red.Ok, for one, I am glad you found something that worked for you. I also said Dyna Jet and should have also added Cobra's jet kit. These are the two usual kits sold/ bought when told you need a jet kit. They have smaller jets than the factory main and you are going backward if you install one. I have heard good things about Factory Pro.
I can't remember for sure because it's been so long and I'd have to check, but my DJ kit cames with main jets up to 220.....way more than anyone would need. I ran the DJ195 on my bike when I rejetted for four years, and it's a bigger jet than the stock 195. I eventually went with the DJ200 after I decided to re-tune for a little better performance.
The original question was whether he needed to rejet after only doing a Clayton Mod. That answer is no.
Not all bikes are the same. Generally, I'd agree with you on the Clayton mod, but if someone puts on a new exhaust and does not change the airbox, you may or may not have to rejet. It depends on many factors including altitude and weather conditions in your area. There are many on here who did have to rejet. I was one of them. My bike ran too lean when I put on my Bigshots so I waited until I bought an open airbox before I rejetted.
I still stand behind what I say about jet kits in general and when you do not need one. And the SCAR mod, if done correctly, will cover most people who only add pipes and a free breathing air filter or modify the airbox.
The other thing I want to bring up is the "A/F" screw. It's really the pilot jet and adjusting it only affects fuel flow up to 1/8 throttle. It DOES NOT affect fuel flow across all throttle positions. Generally, if I remember correctly......
Pilot jet - up to 1/8 throttle
Needle velve - from 1/8 to 3/4 throttle
Main jet - from 3/4 to WOT
If you ride around for a hundred miles and figure out you're lean, you'd have to do plug chops at different throttle postiions to figure out whcih part(s) of the circuit is running lean. May be more than one.
All pretty much true.................Johnnycheese I think is the guy that had the shop.......& yes Poison is da man........These bikes mostly do run lean from the get go (EPA) Best thing is to ask about "like set ups" for a starting point & go from there...........I've got the old dynojet kit & still ended up getting a 210 jet as my kit only went up to a 200 & that was too small for a Thunder air box. The best thing you can do is to also get one of the over sized pilot screws as this makes adjustments a snap (like the Hick Screw) If I were to buy a kit today I would get the Factory Pro kit with a 195 200 210 set of mains.................................:mrgreen: RodI'd also like to point out that Poison knows more about these bikes than anyone on here, so I'll defer to him when it comes to stuff like this.
We also had a guy here who owned a dyno and knew this stuff inside and out. If you have access to a dyno and the guy tunes as well, then that would be the way to go. Then you won't have to remove your tank and try different things a thousand times like many of us did.
With just a pipe change and stock airbox, you don't need a jet kit...Bike will more than likely run like crap if you have one installed...Don't waste your money...I just bought a DG Hard Krome Strippers exhaust in black and was wondering what jet kit I should buy. What is the difference in stages?