air cutoff valve.

[millerdog]

I have a question for the carb gurus. If the air cutoff were leaking around the o rings, would this cause a WOT stumble. I think I have a leak somewhere, but can't find it. The bike will stumble, and then recover when cracked wide open from cruising speed. It then will stumble, and take a while to smooth out when you try to level out to cruising again. I have some new Honda float valves, and seats to put in, as the old ones were looking rough when I rebuilt them. Has a new Randakk kit in it a couple months ago.The air cutoff gave me a fit this time re installing. Don't know why they didn't cut the recesses a little deeper for them o rings! LOL!

[jdvorchak]

bumping this so you don't think no one was reading. Sounds like a tough one. High speed stumbles always perplex me. sometimes it's carburation and sometimes it's ignition. Air cutoff should only let air in when the throttle is returned to idle quickly. Your description sounds like maybe it's lean on acceleration and goes rich when you let off the throttle. Since I'm guessing I'd pull the carbs and recheck the float settings to make sure they are spot on and all 4 are set the same.

You didn't mention if you have stock air cleaner box and filter.

[millerdog]

I do have stock air box, and filter. I was running an open air cleaner with a K@N filter, with no problems at all. I did go with a Hondaman ignition, but I don't think that's the problem. I have to pull them this weekend to put new float valves, and seats in, so I guess I'll find out more after that. Synchronized with a carbtune tool, and its spot on. So is my timing. Had no problems with a DynaS. Of course, the float valves looked really bad on this last rebuild, so that may be it. Thanks for the feedback. I'll post results after the weekend. By the way, the carbtune synchronize r is THE tool to have. Excellent tool. Anyone on the fence about one of these, should just get one. You won't regret it!

[olchris]

If your unsure whether the air valve thingy is sealed properly on maybe sucking air you could easily check it by spraying "chain Lube" onto it several time while its cold... the chain spray will form a thick coating with several applications and prove the seal (Castrol chain Spray O-R is my fav!).... i dont think it the valve as you would have a constant problem... but you need to eliminate it as a cause...

[ericheath]

Air cutoff valves are dark and mysterious. I'm thinking...scary... that the missing oring, not the small one, wouldn't affect running. It's normally open to the plenum, now it's getting some outside- unfiltered air. Eventually it will allow too much dust and debris in and begin plugging the small hole and the idle air jets. Since it only controls air to the idle circuit, it should have a noticeable effect at cruise speeds.

Was your plenum wet or dry before you changed the float gaskets?

[Old Fogey]

I'm thinking more likely that you have a sticky piston(s). Make sure that the guide pins are so shiny you can see your face in them, and I use Solvol to polish the bores in the caps. Make sure that you remove all traces of polish before refitting.

The floats height would make a difference if you have them set too low so that the bowls don't fill properly, giving a weak mixture.

For the air valve, I use a TINY spot of superglue to hold the O rings in place. 'But John that will make them more difficult to remove!' Sure, but your next rebuild might be in another 30 years, so who cares!

[rcmatt007]

I am with OF, stumble at a steady speed (sort of feels like "missing") is a stuck CV slide. they are meant to micro adjust as you go down the road. Just a little but of sticking prevents this. But lay on the throttle (or shut it way down) the vacuum over comes the sticking and it works right

[millerdog]

All good points guys. I did polish the pistons very well when I did the last rebuild. I'm going back in this weekend. I'll look into all of this. Thanks for the advice OF, on the super glue. I'm gonna get to the bottom of this no matter what!

[millerdog]

I got the new float valves, and seats in. Reset floats, and it made a noticeable difference in the way the bike ran overall, but the hesitation is still there. Not as bad though. I'm still thinking!

[82aspy]

any info on the ignition system? how are the plugs? fuel filter? was the prob there before the randakk kit?

[millerdog]

I have a Hondaman ignition, iridium plugs. Randakk fuel filter. Seems like the problem started after the ignition swap. I'm running copper core wires with 5 ohm coils. Resistor plugs. Resistors taken out of the plug caps. The plugs have a good color, although they look a little on the rich side.

[gltriker]

If I've processed this thread correctly, you had removed a DynaS, and installed a Hondaman ignition in it's place.
Does that system require the reinstallation of a points' baseplate and reconnecting the OEM condenser?

[millerdog]

It does require the points as triggers for the ignition. The condensors are removed. I got conflicting info on the condensors. The instructions for the ignition say to disconnect them, but on his website, it says to leave them. Not sure it would matter either way with a transistor ignitor box.

[jdvorchak]

Even though it's transistorized the condensers would still offer spike protection, from any back EMF, while not affecting performance. I'd leave them.

[gltriker]

It does require the points as triggers for the ignition. The condensors are removed. I got conflicting info on the condensors. The instructions for the ignition say to disconnect them, but on his website, it says to leave them. Not sure it would matter either way with a transistor ignitor box.

It's been a while since I read about the Hondaman system installation instructions.
I believe the condensor can be left mounted on the battery frame, but no longer connected to the circuit.
Then, in the event the Hondaman system becomes problematic, the original points' system configuration can be restored by disabling the Hondaman unit, and plugging the hibernating condensor leads back into their original locations.
Maybe yes, maybe no?