Tbr7 update, more carb "fun"

[Captcj68chris@aol.]

Hi all, been messing around with my carb a little more. This is what I have today. 105 jet ( I don't think there sized properly) 1 shim under needle and 2 turns out on the air/fuel screw. Also put in the dr8ea plug. that they gave me
Bike started with no choke, and when warm ran a little bit stronger, Still seems to lose (pulling power) at higher rpm without any hiccups,burping,farting bogging, sneezing,puking, and what everyone describes. If I switched it to half choke, then it would "act up". Before carb tuning I would run on half choke.
This tells me I headed in the right direction correct? Also higher speed in gears I pushing a little over 40 mph now in third with only a 17 tooth front sprocket
My 42 rear should be here soon, I hope.
Safe riding!
Christopher

[Kenstogie]

I would guess that you probably would need to free up your exhaust IE put a new one on or gut the cat. you might find that you will then need an even bigger main jet. jm2cw...

[kingofqueenz]

Chris,

I personally think you are closer than you think, if you mess with the exhaust you will need to retune the carb.

I'm very curious how the 42 tooth rear works.

May I ask where you purchased it from ( a link etc. )?

[Megadan]

Originally Posted by kingofqueenz

I'm very curious how the 42 tooth rear works.

The 42 rear on your bikes with the 17 inch wheels will behave exactly like a 45 rear does on the Hawk. Aka, he will have the same overall gearing that I and many Hawk guys run.

[Megadan]

Originally Posted by Captcj68chris@aol.

Hi all, been messing around with my carb a little more. This is what I have today. 105 jet ( I don't think there sized properly) 1 shim under needle and 2 turns out on the air/fuel screw. Also put in the dr8ea plug. that they gave me
Bike started with no choke, and when warm ran a little bit stronger, Still seems to lose (pulling power) at higher rpm without any hiccups,burping,farting bogging, sneezing,puking, and what everyone describes. If I switched it to half choke, then it would "act up". Before carb tuning I would run on half choke.
This tells me I headed in the right direction correct? Also higher speed in gears I pushing a little over 40 mph now in third with only a 17 tooth front sprocket
My 42 rear should be here soon, I hope.
Safe riding!
Christopher

First. How many miles on the bike now? I ask, because if it is still breaking in, then you can chase your tail in circles trying to hunt down a problem that might not exist.

If it has more than 500 miles on it, preferably 1000, then the easiest way to find the right main jet is to keep increasing in sizes (half steps, or 2 points at a time) until you start to experience a rich bog. You will know it when you hit it because once you open that throttle, the bike will almost stall, and then sputter and stutter. If you let off the throttle it will come back almost immediately.

Keep track of how each jet pulled to redline in a higher gear (at least 3rd or 4th). Once you hit that bog point, you will find that a full jet size back - or 5 points - is usually just about right.

For an anecdote, when I was tuning my first Hawk with a Mikuni clone. I had full upgrades, but the jetting references at the time weren't that great, so I tossed in a 25 pilot and a 110 main. Found the pilot to be a tad lean at light throttle, so I ran a 27.5, and then got the idle mixture sorted.

After all that I took it for a ride and found that wide open seemed a bit "flat" feeling, almost a dry feel to it. So I progressively went up, 112, 115, 117.5, then a 120. The 112 pulled stronger but still had a hesitation and then the 120 was my bog point, rolled on wide open and the engine just came to a dead stop lol. Let off the throttle and it came back to life. Dropped back to a 115 main, and voila, perfection.

Just remember 2 things. 1, The engine needs to be hot for any jetting work, otherwise you are just wasting your time. 2, Don't push super hard with those wide open pulls, Just have the revs up and Roll into the throttle for a few seconds to get a feel for how it behaves. If it feels a bit off at all, lay off the throttle, go back, do the next jet.

[Captcj68chris@aol.]

Hi guys, thanks for the replies. The bike now has 230km. On it. I don't have tachometer so I don't know rpms, bike feels the best it is yet. I'm gonna leave it like that now.ill do more miles and than check the plug. I'm used to 2strokes and the "way" they rev, but on this bike, just feels like it goes flat, and still revs some more. I'm gonna keep it this way some more, let's see how it feels when it's summer. I bought the sprocket on Amazon
It's a JT.Sprockets MOTOCHEEZE link. Amazon seems to have faster shipping than
USPS.
Safe riding
Christopher

[kingofqueenz]

Thanks for the sprocket mention.