Fórum Kzrider

J is jetted differently as it has hotter cams than a “K”

Well... it's been a Summer. Mom fell down and broke her neck so most of my weekends have been spent helping her out. I'm finally getting some time to work on the bike again. Here's what I've found. First off, the air filter hasn't been touched in a decade (whoops!) and is packed full of oil and dirt. That alone could have been the whole issue. OK, I decided to order one of those foam styles since they're worked well on my truck and I have the oil for them. Seller shipped the wrong part so I'm waiting for the next shipment. Meanwhile I got the carbs off the bike and finally cracked them open yesterday. And oh boy. The bottom of the bowls (the depression where the drain screw sits) was completely full of rust. I feel like that could have accounted for the wild bowl level measurements I took in the Spring? OK fine, obviously I need a better quality fuel filter. Cleaned out the bowls and was shooting water through the jets, and wouldn't you know it, I dropped the last one in the yard and couldn't find it. OK I'll grab a new set. Except everything I find says they should be 127.5 and these are 122.5. The bike was rebuilt with parts from a J and a K, and something bad got stripped out when trying to reassemble the J carbs so I ended up rebuilding with the K's. Now this has me wondering if the size difference accounts for the weak throttle? I still have all the J carbs and their parts, so I want to take the main and needle jets, and the jet needles from J carbs and fit them into the

So is the move to replace the spark plugs and see how a fresh set of plugs ages? Also, the flash is kinda deceiving but the rest of the spark plug besides the electrode is completely coated in carbon. I have included a photo without flash and I think you can see a bit better. I did do a bit of googling on spark plug colors but I didn’t find anything that I thought was a solid match to what I have.

That is running lean if I've ever seen lean spark plugs. The whiteness indicates that it is running lean. You should be looking for a tan color. That is probably from when the engine was still running lean as it can take a while for the plugs to be read after changes depending on how you rode it. There are charts online that can help you with spark plug color, just look up spark plug color meaning or something of the llikes.Thr spark plugs won't tell you the full story unfortunately because its telling you the average of all of the rev range you used compared to if you rode the bike at 5k rpm for 10 minutes then kill-switched the bike and read the plugs which would tell you the mixture in the midrange, for example.

Welcome from the extreme west end of long island.

It is the cylinder block. I was thinking along the lines of your suggestions. I wasn't sure if I could double up on the base gasket. I dont think I need to take to much off so a double base gasket could be the answer if I need addition height. Thanks!

Welcome from IL! Bike already looks nice, can’t wait to see the progress you make. Good luck!

No more riding this until my exhaust comes anyways—took it out today and I feel terrible riding it anywhere, especially whenever I pull up next to cars at lights. Got a lot of nasty looks and I was wishing I had some way to let them know that it wasn’t by choice.. anyways, I was able to acquire a spark plug socket so I yanked the #4 plug today and took a look at it. I’ll attach a picture. It looks pretty covered in carbon, except that the electrodes are a different, lighter color. Is the carbon fouling from the old running condition since the pipes have only been off for a few miles total, or would it have changed the plug completely in that time to indicate how it’s truly running now? The texture also looks a bit messed up, could that be damage from running hot before rejetting? If anyone is more experienced with reading plugs, could you take a crack at the image I attached and let me know what you think? Should I replace these guys once I get the exhaust as well or can I just clean them? Thanks!

On a different note. Found out z250 pistons come in std, +0.50mm and +1.00mm. Bikes done 57,000ks. If i look after it might get around 100,000ks before it need a re bore. With two re bores up my sleeve, might get another 80 years out of the bike. Lol

Not sure. If the image is correct, it's both. bth, with everything I've gone through, i just want it fixed. Getting an aluminum one is worth the $ for peace of mind. As for the listing, i posted the models this Tee fits according to the workshop manual i have. I cant confirm that it fits any other bikes. I assume he did some research to see if it fits others. but thats an assumption. At the end of the day, do your due diligence.

Yea I remember reading about the external diameter issue, however the mod I am referring to happens inside the fork and allows the fork to extend further giving you around 32mm extra without moving the forks in the yolks