Has anyone rejetted there z250 yet? For any reason exhaust, air box mods etc.

 

i found a jet kit for my yoshimura exhaust. it need stage 1

 

I found a jet kit too, on Rocky Mountain. I was wondering how you do it though. There is nothing in the manual about jetting. Does it come factory with an adjustable jet? Do you have to take the whole carb off? Where are the jets located on the carb? Think I could just adjust the factory jet or air/fuel screw? This is why I'm asking. I took my s/a and baffle out, and it sounds pretty good. After I rode it for a little bit, my spark plug was white meaning I was running lean. I figured for the time being I could get the K&N jet kit and try different jets until it runs good w/o the baffle, and maybe the air box lid. I'd rather keep the air box lid but if it runs rich just going one jet size up I would have to make some air box adjustments. This is obviously until I get a new pipe. Any help would be appreciated, Thanks

 

WELL DOES IT RUN FINE WITHOUT THE BAFFLE AND S/A IN? bECAUSE i TOOK MINE OUT AND IT RUNS FREAKING FANTASTIC BUT i HAVE ONLY RODE IT LIKE THAT FOR ONE DAY SO i HAVENT GOTTEN A CHANCE TO TAKE THE SPARK PLUG OUT TO CHECK AND SEE IF IT IS RUNNING RICH OR NOT. DOES IT RUN LIKE CRAP FOR YOU OR IS THE PLUG WHITE EVEN IF IT IS RUNNING GOOD?

 

It runs great w/o the S/A and Baffle in, but like I said I checked the plug and it was white. I put the s/a and baffle back in and ran for a while and the plug was brown again like its supposed to be. I just don't want to melt my piston. Do you know if you can adjust the factory jet or the air/fuel screw. I'm planning on getting exhaust, jet kit etc., but after running w/o the baffle I don't want to put it back in.

 

K&N jet kits are just re-packaged DynoJet jet kits. Each kit comes with instructions for your altitude and pipe setup. You'll have to take the float bowl off to get to the main jet. You'll have to remove the slide cover to replace the needle and the slide spring. You might be able to do this by just loosening the carb clamps and pulling the carb out of the rubber airbox and intake boots. The Mikuni carb on the 250 is similar (if not the same) to the carbs on the late model King Quads and 250 Quadrunners. I have re-jetted both and it's not that difficult.

Hope this helps.

Mark

 

Thanks a lot for the help. Do you know if the kit comes w/ specific instructions for each machine?

 

What harm can taking the Spark Arrestor out cause?

 

I wouldn't think any except (ehhmm)....noise pollution?[img]i/expressions/face-icon-small-blush.gif[/img]

 

Yes, each kit comes with instructions for your machine. In fact if you go to dynojet's web site, they have the instructions posted so you can preview them before you buy.

Sooooooooo, I check out DynoJet's site so I can give you the URL and guess what, they don't make a jet kit for the Z250 yet. Check for yourself at www.dynojet.com and then click on jet kits and follow the instructions.

I go to the K&N site and can't find one there either.

I go to Rocky Mt. ATV and they have one listed but they are out of stock. When Rocky Mt. says they are out of stock on jet kits or K&N air filters, it usually means that they aren't being made yet. They did the same thing before Vinson aftermarket products became available. Rocky Mt. updated their web site with the new ATV models in anticipation that these parts will eventually be available so that when they do, they won't have to change their web site too drastically.

They did this with the Vinson too re: jet kits and K&N air filters. I know because every 3-4 months I sent e-mails to both DynoJet and K&N asking them to build aftermarket jet kits and air filters for the Vinson. During this time, Rocky Mt. had them listed as "Out of Stock" and they weren't even in production yet.

I think the same thing goes for the Z-250. I hope I'm wrong but I'll bet not.

Sorry for the bad news. You can e-mail both DynoJet and K&N and they will respond. I won't hurt to ask. Every few months send another e-mail to let them know there are Z-250 owners that want their products. They will eventually get around to your model. I'd bet right now they're making air filters and jet kits for the new Yamahammer.

Mark