CSC TT250 slightly-missing

[jerhomey]

Originally Posted by Megadan

If it were me, I would go this route over the cheap ebay/Amazon jets

https://www.jetsrus.com/a_jets_by_ca...und_28-xxx.htm

those are the correct jets for the Keihin clones like the one found on the TT250. At the very least, order the OEM equivalents if you don't want to shell out for the real deal. They will still be more accurate than the cheap kits from ebay and amazon.

Obviously the jet kit that CSC sells has a pilot jet and a better idle mixture adjustment screw with a small knurled end (also great to have). However, it sounds like your main issue is at 3/4 throttle and above, which would be the main.

Most of the reading I have done for a Stock TT250 at lower altitude puts the main jet size at a 110, needle in the 4th slot, and 1 1/2-1 3/4 out on the idle mixture screw,

If it were me, I would just order a 108 and 110 from JetsRus and call it a day. They are really fast with their shipping, usually only takes 2 or 3 days to arrive.

Well I put in a new NGK spark plug and ordered a 110 and 108 main jet genuine from jets r us . Ill leave my order with csc for the mixture screw just for the hell of it! Ill give an update once one get the jets, although it does actually feel a little better with the spark plug change too.

Thanks guys !

[Choco]

Originally Posted by Megadan

If it were me, I would go this route over the cheap ebay/Amazon jets

https://www.jetsrus.com/a_jets_by_ca...und_28-xxx.htm

those are the correct jets for the Keihin clones like the one found on the TT250. At the very least, order the OEM equivalents if you don't want to shell out for the real deal. They will still be more accurate than the cheap kits from ebay and amazon.

Obviously the jet kit that CSC sells has a pilot jet and a better idle mixture adjustment screw with a small knurled end (also great to have). However, it sounds like your main issue is at 3/4 throttle and above, which would be the main.

Most of the reading I have done for a Stock TT250 at lower altitude puts the main jet size at a 110, needle in the 4th slot, and 1 1/2-1 3/4 out on the idle mixture screw,

If it were me, I would just order a 108 and 110 from JetsRus and call it a day. They are really fast with their shipping, usually only takes 2 or 3 days to arrive.

So you think if i get a 115 from that website it will be better(more acurate) im down to buy it if it will be better performance if not well i already have these lol

[Megadan]

Originally Posted by Choco

So you think if i get a 115 from that website it will be better(more acurate) im down to buy it if it will be better performance if not well i already have these lol

For starters, those are the wrong jet type for a Keihin. Those are clones of a Mikuni Jet.

More accurate? without a question. I have had that exact jet kit, and found mislabled jets, and just plain incorrectly sized jetting orifices. That doesn't mean they can't work, but trying to accurately dial in jetting doesn't work well with willy nilly sized jet holes.

[Goob]

This is the knobbed screw that Megadan mentions is in the CSC kit. It is very nice for adjusting this mixture because the screw is next to impossible to access with the carb installed. The order of the parts (which come loose) is o-ring, washer, spring, then screw. I left the stock o-ring & washer in place and used the stock spring because the one supplied was too long. These are anywhere from $6 to $10 (as this example) on Amazon. https://www.amazon.com/Motorcycle-Ho...396395&sr=8-14

A second on Megadan's jetsrus.com recommendation. I get the cheaper ones on their site. Really..just 2 days for the right jets. Plus you can get the correct bowl gaskets, drain o-ring, even stainless hex replacement screws for the bowl. Saving a few bucks on Ebay or Amazon junk is not worth it. If you have an odd-ball carb (like I have with a KOSO "PWK30"..which is actually a OLD Keihin PWK28 clone that has slotted main jets rather than hex), then Mike will work with you on finding the right parts.

[Choco]

Originally Posted by Megadan

For starters, those are the wrong jet type for a Keihin. Those are clones of a Mikuni Jet.

More accurate? without a question. I have had that exact jet kit, and found mislabled jets, and just plain incorrectly sized jetting orifices. That doesn't mean they can't work, but trying to accurately dial in jetting doesn't work well with willy nilly sized jet holes.

for the price il order me a 115 then. i gutted the cat from the exhaust and took off the vent off the snorkel so you think a 115 should be good? thats what i got now on the mikuni clone jet and honestly it is running pretty nice

[jerhomey]

Well guys , i have to say so far so good!! I changed out the 102 to 110 yesterday and between that and doing the vavles and changing the spark plug this bike is much much nicer to me. I didnt seem to sputter at all even up to 8k rpms and it seems like it has more power too! Appreciate all the help you have provided me so far. I want to do supermoto wheels next and then change the sprocket to the 45 and see how it goes ! Never changed one before so should be interesting. But so far im happy !!

Thanks again!!

[Choco]

Originally Posted by Megadan

For starters, those are the wrong jet type for a Keihin. Those are clones of a Mikuni Jet.

More accurate? without a question. I have had that exact jet kit, and found mislabled jets, and just plain incorrectly sized jetting orifices. That doesn't mean they can't work, but trying to accurately dial in jetting doesn't work well with willy nilly sized jet holes.

That was the wrong on for my case. It is longer that it doesnt make the under cover of the carb close see pic compare to the one i had. Maybe they sent me the wrong one?Im going to end up ordering the one from csc though the one i have now works really well