Idle Too Low, Out of Adjustment Range

[Phantom552]

Over the weekend I ran through Carbs 102, got everything fully cleaned and rebuilt, put it all back on the bike, fired it up and started balancing with a Morgan Carbtune.

During the synch process, the idle dropped, and after trying to correct it the idle adjustment screw is at full lock, unable to raise the idle past about 1000-1100 RPM. What did I miss here? lol

[Kreylyn]

Over the weekend I ran through Carbs 102, got everything fully cleaned and rebuilt, put it all back on the bike, fired it up and started balancing with a Morgan Carbtune.

During the synch process, the idle dropped, and after trying to correct it the idle adjustment screw is at full lock, unable to raise the idle past about 1000-1100 RPM. What did I miss here? lol

Well, I could go into a multi paragraph description of how all the stuff works, but I'll skip that unless you really need it.


Simply put... you adjusted things so that the butterflies on other carb bodies are holding #3 open some what. #3 is the one connected to point the idle adjuster pushes on.


Since they are all out of sync, this particular sync issue = very low idle. Most likely the other 3 are all closed, and only #3 is open... so your forcing it to be a low idle situation.


You may find that doing a non running "bench sync" will help to bring things back to a closer starting point that you can then do a better fine tuned running sync.


krey

[Phantom552]

Well, I could go into a multi paragraph description of how all the stuff works, but I'll skip that unless you really need it.


Simply put... you adjusted things so that the butterflies on other carb bodies are holding #3 open some what. #3 is the one connected to point the idle adjuster pushes on.


Since they are all out of sync, this particular sync issue = very low idle. Most likely the other 3 are all closed, and only #3 is open... so your forcing it to be a low idle situation.


You may find that doing a non running "bench sync" will help to bring things back to a closer starting point that you can then do a better fine tuned running sync.


krey

Thanks Krey, figured it would be something easy that I simply overlooked lol. Ill try the sync on the bench first next time I have an afternoon to kill.

[Pheasant]

Idle issues

Kreylyn, I am having the same issue with my bike could you give me a bigger breakdown of the problem?

Did you fix your idle Phantom?

[Phantom552]

Kreylyn, I am having the same issue with my bike could you give me a bigger breakdown of the problem?

Did you fix your idle Phantom?

Yeah, bench synching the carbs then putting them back on sorted it out fairly well. Here's the bit from Carbs 102 on it:

Visual Synch
* Reinstall the idle adjuster cable until it just barely touches the starter tab of the carbs.
Now look into the engine side of the carbs at the butterfly valves. (There are three small
holes – familiarize yourself with them.) Look at carb # 3 and adjust the idle cable until
the first small hole (towards the outside of the carbs) on the bottom of the carbs is HALF
VISIBLE. Then adjust carb # 4 using its idle adjustment screw, (located from the top
between the carbs – it’s on the arm that moves when you twist the throttle). Take this
carb to the same point by only adjusting the screw. DO NOT adjust the cable any more –
it is only for carb # 3 at this point. Next, adjust carb # 1 to WHATEVER carb # 2 is, so
they are equal. Then, adjust carb # 2 to the same point as 3 & 4 (first hole half open).
Once all four carbs are equal and at the same point, (HALF the first small hole showing
open) you have visually synchronized your carbs! You are now ready to reinstall
them in the bike and synchronize them exactly.
* Install the air box onto the carbs FIRST!! The clamps face down so that the screw
heads can be reached from the bottom and the outside, 2 each, IE: 1 & 2 face left, 3 & 4
face right. You can also remove the air filter to PUSH the rubber seats on over the carbs
by sticking your hand inside the air box to assist. Once you have the air box fully seated
with all fours clamps back on the carbs then reinstall the filter.
* Reinstall the throttle cable(s) while the carbs are still off the bike.
(MUCH easier!)
* Reinstall the carbs. Make darn sure that the clamps at the engine intakes are very
loose and are up top! PUSH (HARD) on only the carbs themselves to seat them back
into the engine. Crank down the clamps being careful to make sure the screws are at the
top


Unfortunately after this part of the process I went and filled up and got some bad gas, which 86'd my fuel petcock and flooded out the crankcase as it sat in the driveway overnight, so ill be pulling it all apart again and starting a new thread for advice on my latest issue lmao.