Adjusting carb needles

[northwind]

Originally Posted by Fuzz

I couldn't find the jets on PDQ, only the full kits. I'm still a little unsure of what size I'm after. The DJ manual says to use part no DJ138 for an aftermarket exhaust, but as the standard size is 137.5, it doesn't quite seem enough.)

Like Ben said, just phone up for the jets, they usualyl have them in stock and they deliver super fast. Good shop.

For the jet sizes though, personally I'm of the opinion that the DJ suggested jetting is absolutely hopeless. their instructions are about 6 years old now and I'm pretty sure they were put together for the very first K&N- the one that was more restrictive than stock- and who knows what exhaust system. If you're buying a kit, buy Ivan's, JHS's or Factory Pro, and if you're not, just ignore the DJ nonsense.

IMO!

I had a race can fitted to mine without any other mod and it ran fine. I then added a K & N filter and the bike started to run seriously lean. I changed the main jets and all was well.

[TSM]

Would a good starting point for:

LeoVince slipon & K&N

DJ160 mains or should it be a bit larger like DJ170's?

It it a good idea to get slighly smaller ones for the rear carb than the front, if so by how much??

[21QUEST]

Originally Posted by TSM

Would a good starting point for:

LeoVince slipon & K&N

DJ160 mains or should it be a bit larger like DJ170's?

It it a good idea to get slighly smaller ones for the rear carb than the front, if so by how much??

DJ160 will be too large for a K+N filter.

I know Northy does not trust the dynojet kit instructions but IMO they are okay. Like he said their are two kits - Stage 1 and stage 1&3.The first is not available anymore AFAIK except someone has some old kit they are still selling. The second kit they brought out is the stage 1&3 and that is what you should be gettinmg if you decide to go for a Dynojet kit.


Cheers
Ben

Originally Posted by TSM

Convertion chart for Mikuni vs Dynojet jet sizes

http://www.ds650.net/mikunivsdynojet.htm

Acording to this sheet, 160 Mikuni are nearly the same as 170.07 dynojet

Thanks for the info, but now it makes even less sense

If a Mikuni 160 is roughly the same as a DJ170, then a DJ138 is going to be considerably smaller than a stock Mikuni jet on the SV.

I've also heard from another forum where I posted a similar message, that Mikuni measure the jets both with aperture size and flow rate, depending on which jet it is (hex headed or round headed.) I think I'll give up for a bit until I've done some more research. Thanks for all the help anyway

Yes, I'm running the racing filter, fully opened up at the top.

The difference between the Mikuni and Dynojet jet measurements are that Mikuni measure flow rate (cfm) and DJ use a linear measurement. You can still use your stock needles, it's just that they don't have the same degree of adjustment.

As has been said, just doing the pipe you don't need to mess with jetting but you might as well do the filter as well to have some fun.

The key with getting the individual parts, especially needles, is finding a place that imports all components and usually don't sell jet kits as a whole. Jets are a piece of **** to get and qite cheap too.

The variation between jet sizes, front and rear, should only be one size. Anything more makes the bike lumpy at low revs and less responsive as one cylinder is rich, the other lean.

[TSM]

Well i have ordered DJ140 to start off on, it will be better than what is in the carbs at the moment for when i put the filter on. Ile get it dyno'ed and see what it does.