GS 500 and Dynojet jet kits

[oklahoma_mike]

I have owned a GS 500 for a while now and it is becoming a great workhorse. I ride it to and from work. It has around 10K on it and is holding up nicely. The only issue is the ingorant PO put a dynojet jet kit in it and that runied the carbs what ever you do do not waste your money and A LOT OF YOUR TIME buying and installing a dynojet kit. It will never run right and you can just replace the jets and get the same effect for $16 bucks. I have had a few bikes that I bought cheap because the owner bought a dynojet kit and was never able to get the bike to run right. I just pulled out and trash the kit. Then bought a few carb parts to replace the ones the kit trashes and be on my way.

So GS500 good
DynoJet BAD!!!

[Matt]

Thanks for the input Mike. I was considering buying one of those awhile back. I will make sure to stay away!

[oklahoma_mike]

The main issue in my experance is the dyna jet needle and the slide mod you have to do. You drill out the slide so you can never go back to stock. I never could get it right I put in about 25hrs total changing setting and riding. I could pull the carbs change anything and put them back in and be riding in 10mins or less. I must have done it 1000 times

[Intruder1400]

Any jet kit that comes with a drill bit should be thrown into the nearest trash can... both dynojet and k&n sell these type kits and sometimes they even file the numbers off the jets and stamp their own numbering systems on them so it's always a mystery to what you're really putting in. Some of them give super thin needles along with smaller than stock mains (K&N did that to me in a kit for my 87 gsxr 750) or super fat needles along with huge mains (Dynojunk did that to my friend for his gsxr 1100) to keep you or the installer thrown off to what size combos are giving the "improved" mixture. in both cases the bikes were faster but just wouldnt behave themselves good enough for normal riding.

if you know your stock jet sizes you can easily tune your bike without a kit and it'll run good at all speeds.. not just full throttle. you can change the needle settings on non adjustable needles by using 4mm washers under the clips, the 4mm washers are 1/2mm thick so 2 washers = 1 groove setting... this also means you can make 1/2 adjustments for further fine tuning on adjustable needles as well...

Rules of thumb are go up 1 size for a k&n filter in the stock air box, 2 to 3 sizes for pod filters... go up 1 size for aftermarket exhaust, 2 sizes for drag pipes
If you have drag pipes with a k&n go up 3 sizes and for drag pipes with pods go up 4... that covers the mains... for the most part... the pilots (idle mix circuit) in most cases only need to go up 1 size, sometimes 2.
that covers full throttle and idle mixture. remember, those are rules of thumb and you most likely wont get it perfect on the first try.

For part throttle acceleration you adjust the needle height... if it feels sluggish, raise the needle... if it hesitates then the needle needs to be lowered. there are different needle sizes that can be put in as well if more fine tuning is necessary.

If you really insist on rejetting and want a kit with all the right parts in it go with Factory Pro.. I did my Suzi with the Factory Pro kit and it behaves as good as stock when it needs to and has tons of power at the same time.
Why did I pay for a kit for this bike? ... I did it cuz the kit came with everything I needed plus a few sizes up and down from their recommendations so the bike could be tuned perfectly according to the other mods it has. not to mention the price of the kit was only a few bucks higher than buying all the stuff on my own.

[oklahoma_mike]

Yea I got mine sorted out and it runs great now up two on main, new diaphrams and alum needles w/ one washer and up one on pilot. I spent about $60 total to fix the Dyno-crap!

[oklahoma_mike]

Originally Posted by Intruder1400

you can change the needle settings on non adjustable needles by using 4mm washers under the clips, the 4mm washers are 1/2mm thick so 2 washers = 1 groove setting... this also means you can make 1/2 adjustments for further fine tuning on adjustable needles as well.

GREAT info, the only thing to keep in mind with doing this is that the washers are adding weight to the slide and will slow it's reaction down a little bit now this is a very VERY VERY tiny amount, but for a split second your bike will be lean as the slide reacts slower. For 98% of the bikes out there that is not a big deal as no matter how they are tuned they will be lean for a split second in certain situations, But for the other 2% you need to remember to roll a little slower on the throttle on those 100 degree days or run a slightly higher octane.

My GS had an occasionally ping on very hot days after I fix the Dynojunk I keep thinking it was the aftermarked slides I had to buy because the dynojunk kit ruined the stock ones. So I keep going up and up on the needle only to have it ping worse. I was already at the lowest setting on the clip so that meant adding washers. It took me some time to realize that the weight was the problem so I took the washers out and sanded the needle slightly and tada she was perfect

Now a bit of detail about the GS I had an advance on the ignition to bump the timing and the head had been milled so the compression was up slightly, couple that with the slower slides, 105 degree days and a rider that likes to abruptly change throttle position and you have ping. So like I said 98% of the bikes out there the weight of washers will NEVER be a problem. Sorry for the long write up for something that will probably not affect anyone on here, but I spent many a HOT day in the garage in the middle of summer in Oklahoma to learn this lesson.

[peterjems]

DynoJet jet kits with each of our systems. We then recommend whichever brand works best with a particular pipe application. In cases where there is no difference, we offer both and leave the choice to the tuner's preference. In cases where neither is satisfactory to us, we will try to have a specific kit assembled to our specifications by DynoJet and this kit will be referred to as a factory jet kit.