Jet's Hawk 250

[Weldangrind]

Originally Posted by jet321

What kind of top speeds do you guys get on the hawk?

I get to 55 and she starts sputtering like it's hitting a rev limiter, I thought it was a main jet issue but I tried a 105 and it ran worse. Am I doing something wrong?

I can top out somewhere near 65 if I'm on level grade and not fighting wind, and that's with a 200 Lifan. There is more in your Hawk, you just have to unleash it.

[jet321]

I figured it out, it wasn't a jetting issue. I was running a air filter straight off the carb and it wasn't running right at the top end. I ran the filter into the filter box and the bike runs great now and will top out at the 65 mph everyone has claimed, this change seems to have fixed the issue. The popping and gurgling coming off of throttle has disappeared as well, the bike sounds and runs better. Does anyone think the bike runs better with a slightly restrictive intake?

Has anyone else experienced this? I figure I'm running the bike more rich now. It really surprised me how much a difference it made. I've been messing with the jetting for the past couple weeks when I get a chance, and I couldn't get the mix right.

Also, does anyone know where I could get a good replacement throttle assembly? Mine has play in it, figure I should replace it, RPS wants $40, that's a bit steep.

[2LZ]

Originally Posted by jet321

I figured it out, it wasn't a jetting issue. I was running a air filter straight off the carb and it wasn't running right at the top end. I ran the filter into the filter box and the bike runs great now and will top out at the 65 mph everyone has claimed, this change seems to have fixed the issue. The popping and gurgling coming off of throttle has disappeared as well, the bike sounds and runs better. Does anyone think the bike runs better with a slightly restrictive intake?

Has anyone else experienced this? I figure I'm running the bike more rich now. It really surprised me how much a difference it made. I've been messing with the jetting for the past couple weeks when I get a chance, and I couldn't get the mix right.

Also, does anyone know where I could get a good replacement throttle assembly? Mine has play in it, figure I should replace it, RPS wants $40, that's a bit steep.

Strange. I've never had an issue with a pod right off the carb (other than fire). Mrs 2LZ TT has the little pod and it runs incredibly well. Whatever works best for you, stick with it!

Is it just slop in the cable? Have you adjusted it?

[jet321]

Originally Posted by 2LZ

Strange. I've never had an issue with a pod right off the carb (other than fire). Mrs 2LZ TT has the little pod and it runs incredibly well. Whatever works best for you, stick with it!

Is it just slop in the cable? Have you adjusted it?

I thought it was strange too but now she revs out past 6k now, which is where she was choking.

Yeah there's slop for sure, at least an inch or two of travel before lifting the slide at all. I adjusted it as best I could but it didn't fix it.

[Azhule]

Originally Posted by jet321

Also, does anyone know where I could get a good replacement throttle assembly? Mine has play in it, figure I should replace it, RPS wants $40, that's a bit steep.

Might be time to give CSC a call and see if they have a part from the TT250 that will fit your HAWK... there prices are extremely reasonable even after shipping

http://www.cscmotorcycles.com/TT250-OEM-PARTS-s/306.htm

I found a few parts but I'm not sure if it's just the rubber grips or the throttle assembly too... but everything I was able to find was under $10 each part

[jet321]

Originally Posted by Azhule

Might be time to give CSC a call and see if they have a part from the TT250 that will fit your HAWK... there prices are extremely reasonable even after shipping

http://www.cscmotorcycles.com/TT250-OEM-PARTS-s/306.htm

I found a few parts but I'm not sure if it's just the rubber grips or the throttle assembly too... but everything I was able to find was under $10 each part

I saw that, but it seems that the TT250 has a choke lever on the throttle assembly?

[Weldangrind]

Originally Posted by jet321

I figured it out, it wasn't a jetting issue. I was running a air filter straight off the carb and it wasn't running right at the top end. I ran the filter into the filter box and the bike runs great now and will top out at the 65 mph everyone has claimed, this change seems to have fixed the issue. The popping and gurgling coming off of throttle has disappeared as well, the bike sounds and runs better. Does anyone think the bike runs better with a slightly restrictive intake?

Has anyone else experienced this? I figure I'm running the bike more rich now. It really surprised me how much a difference it made. I've been messing with the jetting for the past couple weeks when I get a chance, and I couldn't get the mix right.

To me, it seems like it was a jetting issue. My guess is that the jetting was too lean, and placing the filter inside the box slowed the airflow enough to work with the main jet. If you go back to an exposed filter and a fatter main jet, you might find even more power.

[jet321]

Originally Posted by Weldangrind

To me, it seems like it was a jetting issue. My guess is that the jetting was too lean, and placing the filter inside the box slowed the airflow enough to work with the main jet. If you go back to an exposed filter and a fatter main jet, you might find even more power.

I tried that, the mikuni I got had a 100 main in it, and I tried 105/110/115 and it would not run right. What's crazy is there's guys on here at half my elevation and they're running 115's.

I'll look at it again this weekend, there has to be something I'm not doing right.

That's the same conclusion I assumed too.

[Ariel Red Hunter]

Originally Posted by jet321

I tried that, the mikuni I got had a 100 main in it, and I tried 105/110/115 and it would not run right. What's crazy is there's guys on here at half my elevation and they're running 115's.

I'll look at it again this weekend, there has to be something I'm not doing right.

That's the same conclusion I assumed too.

I would try running without the air cleaner hose hooked up to the carburetor. That should tell you where the problem is. If the engine pulls fine without the air cleaner, the problems in the aircleaner and/or the hose. If the engine running quality doesn't improve, try squirting oil around where the carb. bolts to the head, with the engine running. If it runs better, there is an air leak where the carb. mounts to the head. This is often caused by over tightening the mounting nuts, warping the carb/head mounting surfaces. If none of this makes any difference, something is not right in the carburetor.

[jet321]

So I got the 115/30 jets in my carb and did 1.5 turns out on the mixture screw, and the bike is still bogging at WOT and high RPMs 6k+. Do you guys think it's running to lean still? I tried turning the mixture screw out to 2 then 2.5 turns out and then setting it back to original (0 turns) with no luck. I know there are a bunch of threads on this but I haven't seen anything for the bogging. I also checked to see if the carb is clean and it seems as such. I'm at 3,500ft. Thanks again.

Update: I got my shinkos on and put some new levers on the bike and it looks sweet. I'll post some pictures later.

Also, with ARH's post below, I didn't have the 30 pilot jet in it, I'll have to investigate the carb leak. I hadn't seen my thread in ages lol

[pistolclass]

Originally Posted by jet321

So I got the 115/30 jets in my carb and did 1.5 turns out on the mixture screw, and the bike is still bogging at WOT and high RPMs 6k+. Do you guys think it's running to lean still? I tried turning the mixture screw out to 2 then 2.5 turns out and then setting it back to original (0 turns) with no luck. I know there are a bunch of threads on this but I haven't seen anything for the bogging. I also checked to see if the carb is clean and it seems as such. I'm at 3,500ft. Thanks again.

Update: I got my shinkos on and put some new levers on the bike and it looks sweet. I'll post some pictures later.

Also, with ARH's post below, I didn't have the 30 pilot jet in it, I'll have to investigate the carb leak. I hadn't seen my thread in ages lol

Sounds a little fat for 3500 ft. Stock exhaust I assume? drop to 110 and 22.5 or 25, middle needle. then try the screw.

[jet321]

Originally Posted by pistolclass

Sounds a little fat for 3500 ft. Stock exhaust I assume? drop to 110 and 22.5 or 25, middle needle. then try the screw.

aftermarket exhaust w/ gasket