JakeT

Ok so after reading the instruction and a bunch of articles on the forum I took the bike apart. Took the carb off. The instructions said if you have a high flow exhaust and a k&n go two sizes up. So I took out the slides and springs, checked the diaphram everything looked good. Drilled the needle holder and the slide as instructed. Installed the needle, checked the c clip. From what I read since I have the K&N it was best to install the eclip on the 5th notch from the back of the needle. The front was jetted as 178 and the rear 175. Seemed odd but ok. So I went two sizes larger as per instructions 185 in the front 190 in the back. Turned the pilot screw all the way clockwise. Then back 2.5 turns. I determined this by marking the tool supplied in the kit so I had a reference point. Put it all back together, synced the carb with my motion pro. Took it apart to take off the brass fitting for the sync, installed the bolt back on. Put on my gear and went for a quick ride. At first everything seemed great. Throttle response was good low end was good. But as I got to more open road I went WOT and the bike started stumbling and shaking and would not accelerate or increase engine speed. Letting off on the throttle and slowly throttling up seems to fix the problem. My guess is that its running way rich which is why the problem is much more apparent at WOT. I'm not asking anyone to fix my problems. But some input would be nice. Should I back the eclip on the needle 1 notch or should i drop a jet size perhaps 180f/185r? Thanks

nath981

did you do anything with your slow jets. Try #50s and see if that improves WOT. may be running out of fuel instead of rich. Did you read the below thread?


https://www.superhawkforum.com/forum...ad.php?t=12878

8541Hawk

Well instead of just throwing more parts at it try this....

Pull the choke out slightly (actually the enrichment circuit) and see if it gets better or worse.

If the bike runs better, you're lean. If it gets worse you are running rich.

NHSH

That is as simple as it can get to check if the bike running rich or lean

JakeT

Thanks nath, I didn't touch the pilot jets. Before i rejetted I didn't have any noticeable problems at low 1/4 throttle so I had left the pilots alone.
8541 thanks for the suggestion I guess at 12am in the morning I might not be using the best thinking and didn't try to pull the choke to see if it solved the problem.

When I bought the bike it had the k&n filter installed already. My wife and son bought me a dan moto gp exhaust that I installed a few weeks ago and everything ran ok but I was losing on the top end which sugguested to me that I was running a little lean as I don't have the baffles in the dm exhaust.

I read this thread however
https://www.superhawkforum.com/forum...problem-18166/
and it suggests that 2 sizes up might be WAY too rich especially with the needle shimmed in the 5th notch.

I'm gonna go for a ride and see if the choke fixes it or makes the issue more pronounced. and from their either take the jets down from 185/190 to 180/185 and see if that helps at all. Then I can play with the needles. I don't want to do too many things at once cause then i'll never know wtf I did wrong.

JakeT

Ok just got back from a straight I have by my house. And 1st gear no problem. 2nd gear wot stumbling. Pull the choke out once again 1st gear no problem 2nd gear stumbling the whole way up. So that confirms what Im pretty sure I already knew it was rich. Dynojet troubleshoot says also that if you demand hp and it stumbles it more than likely too rich. I'm going to go down a jet size seeing as the needles are more for fine tuning and if I'm that rich one notch back on the needle probably won't solve it.

7moore7

Just pull the choke out a little bit when you do this... you can make a bike look rich when it's running lean if you pull it out too far. You just want to ride it, pull it out slightly (I like to while I'm riding to notice the change) and see if it gets better, not yank it all the way out then WOT...

Hope I'm making sense, maybe you already did it this way. You likely are rich, just trying to avoid mis-diagnosis.

JakeT

Thanks for the advice 7moore7, I did how ever pull the choke out in stages, 1/4 pull 1/2 etc etc. It was way way rich. So at 630 or so when I got up and posted the last post I tore down the bike again yanked the carbs. Rejetted to 180/185 and left the needles in the 5th notch. Set the idle, resynced the bike(as I was led to believe each time you rejet you need to resync.) Tore all the sync stuff out, put it all back together and went for a ride. Wow what a difference. No more chugging, no more flat spots at WOT. I played with the choke a bit to see if i should go richer and it ran worse if anything I think im going to move the needle one notch back and see how it runs. If you change the needle spacers do you also have to resync? I figured any changes to the carb a resync would be ok but maybe no necessary. Perhaps you carb gurus can shed some light on that. It pulls hard all the way up to 9k(I rarely go past 9k as I feel the valves start to flutter and its unnecessary, though I could be wrong. Let me know if you have any suggestions. Thank you everyone for the input you have all been very helpful even you Hawk

matt365

My setup is very close to yours.

I had a 185 and a 190 in it as dynojet suggests... The gas mileage wasn't great, and I could smell the unburnt fuel in the exhaust.

I went to #48 pilots, 175 front, 178 rear. 4th clip.

This setup worked well enough for me.
I went back to a stock filter instead of the K&N and it seemed to help as well.

HRCA#1

What do you know we're back to 8451Hawks set up!

7moore7

Lol, HRCA, weird, it's like he's using a similar bike or something...

JakeT

Hawk doesn't recommend drilling the slides I thought just shimming the pilots?

8541Hawk

Well you can't shim the pilots but.....

No I don't believe speeding up the slides is the answer for this bike, so no I don't recommend drilling the slides and using the lite springs.

Though I do like how the bike runs with stock main jets and one size up on the pilots.

JakeT

Oops sorry you shim the needle right?

8541Hawk

Yes that way you can use the stock needles which actually work very well.

zxbud