Carb Issue

[FalldownPhil]

"Or perhaps they just need syncing and fuel mixture adjusting?"
That is the high rpm problem.
Best,
Phil

[daves79x]

If your chokes are working properly, as Phil said, then your high idle is likely carbs out-of-sync. Do everything else you need to do, then sync the carbs last. Oh, and get your pilot screws at least 2 turns open.

Dave

[cross]

I don't think that choke is working properly as there isn't any fast idle but now when I give it choke, and rev it a bit, it stays a bit above 2k until I switch choke off.
I'll definitely remove carbs when I tilt the engine an d try to adjust choke.
Wouldn't turning fuel mixture screws out more give richer mixture?
What benefit will I have with needle shimming? I found some shims which are .018
Would I use those it the ones from fuel mixture screws?

Thanks Dave

[daves79x]

There is no 'choke adjustment' other than the cable at the carbs. They are assembled properly on the bike or they aren't. I'm meaning that the cable has to be adjusted so that it is not holding the choke plates even slightly when in the full 'off' position. If you get the carbs sync'd I wouldn't fool with the fast idle adjustment. But if you think you are running too rich now, with the pilots at 1 1/4 and everything else stock, then your chokes may not be opening all the way. You'll need to check all that when you take the carbs off. Open and close the chokes several times to see what's happening. If they all work correctly, then you have the choke cable adjusted too tight. Make sure your choke cable is not installed backwards. Make sure the ferrule is at the handlebar end.

If your carbs are perfectly clean and you are running the stock air filter, accelerator pump working properly, pilot screws set at 2 turns, you really don't need to shim the needles. The bike will warm up quicker and possible respond better, marginally, but you will lose 2-3 mpg.

Dave

[cross]

What i meant was to check and adjust 2 fast idle parts that you mentioned in your previous reply.
I followed your tips for all checks before installing carbs, choke was opening and closing fully, i checked this few times. Ferule on the handlebar side is at the pinch and this side was easy to install, its the carb side that is more difficult to set properly. I'm rechecking it tomorrow.
I do not know how rich bike is running, i just left mixture screws out by the book as a starting point and plan on adjusting them as any other carb, one by one and follow rpm drop and rise but i have a feeling that this is going to be harder with 6 carbs as there is so little difference turning mixture in and out.
I put 120 miles on the bike today and it ran just fine with exception of the idling to 2000 rpm for few seconds before returning to idle.
I had no fuel starvation issues but something came across my mind as i was riding.
When i got the carbs on the bike post cleaning and once warmed up, i turned down idle to as low as it would run with out hesitation and according to the gauge, it was about 800 rpm but it could be lower. Now, is it possible, that at this low rpm, engine does not provide enough vacuum for the auto valve to open fully?
This would explain not having these symptoms when hwy riding but when accelerating with high revs as if racing with someone from light to light, fuel bowls would empty quickly. Then once stopped, engine would idle too low and not provide enough vacuum for fuel valve to open fully and fill bowls quickly enough therefore once trying to take off 30 sec or so later, bike would stall.
I mean, if i did not stop after racing it but slowed down and kept on riding, bike would not experience fuel starvation.

Thanks Dave

[cross]

I realigned the choke cable at the carbs and it idles great now!
I have to pay better attention next time.

Thank you guys

[cross]

Hi guys,
Just a quick update,
My bike runs awesome! I think it runs better more I ride it.
This weekend I went with my buddies for a ride and we did little over 200 miles and the only complain is the my bottom is numb!
Seriously, bike is great, few things I need to sort out like carb sync and I keeping missing shifts for some reason. It doesn't seem precise. I'm going to have to see the manual if there is an adjustment that can be made.
Thanks once again for all your help, I appreciate that very much!

Regards
Sasha

[daves79x]

Take your shifter off it's pivot and clean and grease it - I'll bet it's dry. Same goes for the lever pivots at the bars. The 4th to 5th shift has to be deliberate - that's the one guys usually miss. It's a long way around the horn on the shift drum to 5th.

Dave

[cross]

So once it happens and it end up in between 4&5th, what is best to do to minimize grinding?

[daves79x]

I just pull in the clutch and shift up or down again - never had any 'grinding'. Make sure you clutch is adjusted 'by the book', starting under the little cap on the clutch cover.

Dave

[cross]

Well, when this happens to me and I do the same, it grinds.
Also when shifting with higher revs, it feels like an automatic transmission or almost as if there is slight clutch slip.
I have to adjust things again as I'm having more slack now at the lever and I know that I adjusted the hand lever by the book only I could not figure out how to adjust the other end.
Second question I had is that it also feels that shifter has longer travel then I'm used to on other bikes.
Is this normal for cbx? I mean I sometimes miss 2nd as well. I feel like I'm beginner rider!
For shifter lever, did you mean to lube the ball ends?
Thanks

[NobleHops]

Well, when this happens to me and I do the same, it grinds.
Also when shifting with higher revs, it feels like an automatic transmission or almost as if there is slight clutch slip.
I have to adjust things again as I'm having more slack now at the lever and I know that I adjusted the hand lever by the book only I could not figure out how to adjust the other end.
Second question I had is that it also feels that shifter has longer travel then I'm used to on other bikes.
Is this normal for cbx? I mean I sometimes miss 2nd as well. I feel like I'm beginner rider!
For shifter lever, did you mean to lube the ball ends?
Thanks

Sasha, those two heim joints can wear and that tiny amount of play will make the throw longer and sloppier-feeling. Get down there and work the action and watch how much throw there is before the lever on the shifter shaft moves. Clean it all out as Dave suggests and get as much grease in there as you can and that might help.

[daves79x]

I'm referring to the actual pivot the lever attaches to on the footplate. There should be 2 different styles of cup washers (one each), 2 felt washers and a plain washer holding it on. The bushings get dry and dirty and don't allow the lever to move freely, resulting in missed shifts. Yes, there will be some play in the joints and the pivot bushings. You can buy replacement bushings.

Sounds like your clutch needs adjusted as well. It's for sure slipping. Find an instrument that exactly fits the slot in the small cover (on the clutch cover) and remove it. Let all the slack out in the cable adjusters (at the bars and the clutch cover). Loosen the lock nut and lightly seat the set screw. Back out one full turn, then tighten the lock nut, being careful not to move the adjuster. Then adjust at the cover for most of the slack, then the lever adjustment for the final free play. If the clutch isn't shot, that'll fix it.

I use the square end of a large file to take the little cover off. Be careful or you'll bugger up the slot and it'll look like most other ones out there - all chewed up.

Dave

[cross]

I checked clutch cable adjustment today and it was too tight, there was no slack.
I re adjusted it and it does not slip anymore. Now, i know that every bike has a bit of clunk when shifting into 1st from neutral, how much clunk is normal for these bikes? I tried adjusting it with different amounts of slack and i would get from mild to moderate clunk and sometimes, bike moves a tiny bit forward too.
Shifter, there is a lot of slop at the pivot point.
I looked up parts for repair and nothing seems to be available, any known sources that you can recommend?
Thanks

[NobleHops]

I checked clutch cable adjustment today and it was too tight, there was no slack.
I re adjusted it and it does not slip anymore. Now, i know that every bike has a bit of clunk when shifting into 1st from neutral, how much clunk is normal for these bikes? I tried adjusting it with different amounts of slack and i would get from mild to moderate clunk and sometimes, bike moves a tiny bit forward too.
Shifter, there is a lot of slop at the pivot point.
I looked up parts for repair and nothing seems to be available, any known sources that you can recommend?
Thanks

I recommend adjusting your chain How much travel does it have now?