Picked up my Dynojet Kit today

[3L4NS1R]

$108 at Amps.

Now that I'm going away for the weekend, it has to sit on the desk until Monday, and even then, won't have a chance to install it till tuesday.

So until then, I'm just going to be researching as much as I can about installing it, just to make sure there's no unforeseen complications.

Anyone got any advice?

[camchain]

I put a Dynojet kit in my KLX300 and was happy with the result. Quite a bit more bottom end pep. Check yours but I'd be fairly sure your 250 will have a similar type CV carb. The CV carb is the real problem and it can't be fixed with a kit. The slide isn't connected to the throttle cable, it's operated by a diaphram (top of carb) that lifts the slide with engine suck - so you get a delayed throttle response. Good for fuel efficiency and emissions, bad for horsepower.

The instructions in my kit were a bit vague on some points but I had no problem fitting. Does your kit come with a drill? My kit required enlargement of the slide lift hole under the diapram. This gives quicker throttle response. Just drill carefully for a nice neat hole. The main jet in kit was same size number as stock but longer. You'll want to experiment with the needle height a bit to get best result. Just be aware that if you drill the lift hole you probably can't go back to stock needles/jets (Not that you'd really want to).

To get the best results you'll need likely need to get the bike breathing better all round. eg. I removed airbox lid, fitted larger header & pro circuit muffler. Although I had more power, jetting still wasn't perfect off the bottom but never got around to sorting it fully.

Pic for comparison KLX 300 Dynojet needle/main jet. The shape of the Dynojet needle says it all - more fuel off the bottom and plenty of it:

[laserracer]

My son had a dynojet kit on his klx300 made a big difference as well as a big header and muffler after riding a stock bike then his it did make a difference also got rid of that throttle lag that those cv carbs have
have alook at the kawasaki forum on thumper heaps of info on there

[3L4NS1R]

Cheers for the replies! I got the klx300 kit, so yup, will be needing to do some drilling...

Are there any other expendables I need to do the job? (ie. greases, ties, etc)

[camchain]

For a proper before and after comparison, go for a quick ride first, paying attention to how it feels rolling throttle on from lower revs in first few gears.

No need for any extra stuff. Make sure no dirt on frame above where you're working. Although I took my carb off to clean it, I don't think you'll need to remove carb to fit the kit. Just loosen the hose clamps and rotate carb body to get float bowl off for access to main jet. Don't overtighten jet, just nip it up. Would pay to check your fuel screw adjustment as well. Count number of turns out from seated (gently seated - not tight).

When removing diaphram/needle from carb top, just take careful note of how everything comes apart. Eg. I seem to remember a little washer that sits above (or maybe even below?) the needle clip. Lay parts out in a line in the order and position/orientation you remove them. I think there was a plastic needle keeper with 4 legs, make sure it's properly located before putting spring back on.

Having trouble remembering and visualising but if you remove carb I think the only fiddly bit is getting the throttle cable ends (1 'push' cable and 1 pull cable) off and on. I think I undid the cable mount bracket so cable ends can then come out easier. Rotate the throttle mechanism and use needle nose pliers gently on cable end, don't kink the cable. Measure the lock nut position/exposed thread length positions before you remove anything so you can easily get back to the right amount of play for cables. As mentioned the cables don't work the slide, they rotate a butterfly valve in carb throat in front of slide. No guarantee of accuracy of above and I'm sure likely missed some stuff out, but hope it helps. Did it a couple of years ago so memory faded.

[3L4NS1R]

Cheers for the help everyone! operation went well, and almost without a hitch (there were a few moments there where I thought I had fucked it).

Removed the whole carb, mainly because I have large hands that don't cope well in small spaces. Turns out the hardest bit is getting the airbox hose reconnected with the carb... very hard to tell if its completely on!

Took it for a test run last night, seemed to run fine and dandy! More power low down, about the same higher up.

Next step: Get a custom exhaust. I'm thinking cycleworks? Looking for more upper end power now, just to make cruising a bit easier.

[scott411]

a exhaust would be the next logical step, you will want to do the header as well, custom chambers have a goold klx300 pipe which is a copy of a stroker racing one who were the guru's on KLX300's in teh late 90's,

[warewolf]

The main jet in kit was same size number as stock but longer.

Beware apples & oranges. DJ numbers are not the same measure as most carb manufacturers. A DJ jet and say Mikuni jet with the same number will be about 25% different size.

[warewolf]

As a sheer wild-ass-guess, if you are fitting a DJ 300 kit to a 250, any money your lack of gain up top will be because it is way too rich. DJ kits are known to tend to be rich in lightly-modded engines, plus you are fitting one designed for a bigger engine. A restrictive stock exhaust may exacerbate the problem.

Don't know, it's just a thought. Others may well know for sure, or be able to direct you in how to test it.