Idle issues

[philgresty]

your jetting is going to be way off (lean) if your running stock jetting. 40 pilot, 100 main and stock needle clip position (2nd from top) with those pod filters
I ran 42 pilot, 110 main and needle clip in the middle position (3rd from top or bottom) and it ran pretty damn good, for pods.
a bit of an erratic idle was always a problem I had, pod filters don't really lend themselves to a smooth idle, at least not on 550 carbs. My bro runs UNI foam air filters, oiled and that idles better than my k&ns ever did.
Going back to an airbox was the best choice I ever made, Honda really knew what they were doing.
Hope this helps
Phil

[matthewmosse]

Ah, k&n style filters. I tried these, gave up on them as the bike was tempremental as a tempremental thing with them fitted. It worked after a fasion but nowhere near as good as stock setup. I have one bike with a genuine K&n filter that sat under the seat and fitted the standard phlenem chamber so the bike looked stock and with that it was genuinely running very well indeed and had more power than my stock 550k3 which was good going for a cb500 that had been round the clockand some. I do think those filters can work, but you need to be quite skilled and patient to set them up right. I had some on my bmw twin, great on that setup, and my landrover, but the cb I never had the patience to mess  around re jetting to get it working right.

[Wenman]

That is not what I want to hear!! I knew this was going to be a challenging affair hence why I purchased these carbs. The guy came recommended with 35 years of experience in carb building. I told him what set up I had m, pod filters and 4-1 delkevic exhaust and he said he would jet accordingly!
It's strange as it feels so close.. picks up through the revs but won't idle😩
Don't really want to dismantle such beautiful carbs and start re jetting but I think that's where I'm going to end up??

Thanks for all your input I really appreciate it!

[florence]

I have filters like that but run a 110 main jet, runs really well, even ticks over properly.

[Wenman]

Florence is that with stock idle jets #38? Also what exhaust??

[florence]

i don't know which slow running jets but the exhaust is a 1980s Laser 4-1, very loud.

[Wenman]

After explaining my problems to the carb supplier this was the response..

I am at a loss from here to determine what your real problem is. I do know that those carbs should not be your problem. No one but the ill advised uses 110 mains on a motor with 4-1 pipes. Are the plugs still black? Have you moved the timing plate around a little to see if that changes anything. There are also idle mixture srews that will need to be adjusted but you can't do that until it will idle on its own.. Have you tried a power balance to see if all cylinders are actually firing?
Like I have said before the carbs were run and setup on a known good motor and they passed all tests on that motor.
I still want to help but I can't drive over to see what you have to work with.

Any other ideas on this guys??

Alan

[philgresty]

i use 110 main jets in my 550, and that has a stock airbox and 4 into 1 pipes, the hotter cam leans it out a bit though.
Theres no way itll run right with stock carb settings and pod filters, im sure everyone here will agree. Any change to the air supply of the bike will require a change to the fuel supply, more air (pods) = more fuel needed ( bigger jets/higher needle)

[Wenman]

My carbs came with #38 idles and #98 mains so I'm now running #40 idles and #100 which is what was supplied after informing the carb builder of my set up and what he is clearly standing by!

[Ashdowner]

You've got PD46 carbs. On a standard setup the idle screw should be 1.5 turns out +/- 1/3rd turn. Before you start buying things can you say what colour all your plugs are or give us a photo? From my experience the manifold rubbers either have to be in a pretty shocking state to leak or they're not fully pushed home onto the manifold, and for all of them to leak is pretty improbable. Funnily enough I vacuum synched my carbs today and (although I have no leaks) it was pretty amazing how smooth my tickover was with the standard number of turns. I assume you have the needles on the 2nd notch from the top?

[Wenman]

Ashdowner, the screws are 1 turn out and it is running lean according to the plugs! Also the engine is running very hot which I believe also indicates lean!
I think to Richen the mix you screw the screws in but to make up this leanness would prob have them screwed right in! I believe needles are on the second notch!!

[philgresty]

The carbs aren't the dreaded PD carbs, good news there! there is a picture of them on the first page, they are either 069a, 022a or 627b(cb500)
You should be okay with the 40 pilots at idle but 100 definitely isn't enough of an increase in the main jet, and without the needle clip moved to the 3rd it just won't cruise right, constant adjustments and increases in the throttle will be needed to maintain speed, ask me how I know.
Your right, in with the screw richens the mixture

[Wenman]

Phil they are the 627b carbs! Even though it's a pain to change the needle clip I can can do it! I do have 105, 110 and 115 main jets for the 069a's which came off the bike. If I changed the main jet would needle adjustment still be required?
It's not idleing that I'm having issues with and I thought the idle jet would be the one which needed changing not the mains?

[Wenman]

Sadly I have de tabbed the bike as part of the project so can no longer reserve and put stock air intake back on! I assume you can run these carbs on the 550?!

[philgresty]

the 500 carbs are fine on the 550, they were just jetted differently from the factory
If you dont have the airbox to put back on, your just going to have to work with what youve got, either way youll definiely need to drop the needle clip to the 3rd slot to richen up the mid range, if youve already got 110 and 115 main jets throw either of them in, 115 if your exhaust is particuarly open and see how it pulls with wide open throttle
I have seen aftermarket pilot jets that are alot shorter than the stock keihin jets, do your pilot jets have a logo on them? oem keihin is always better. That may be causing your idling issue.

These adjustments need to be made to run right with your set up anyway, regardless of the idle being the main concern right now.
what rpm are you idling the bike at?
Also what position is the choke lever in when your running it, it wouldnt be the first time the position of choke on and off was confused (the thump tab on the choke lever becoming horizontal is full choke)

Phil