idle screw versus throttle cable adjustment

[indyjoel]

Hi
dipped and cleaned the carbs, turned the air screw out around three times (to ease starting), would not idle

With the choke out it would idle.

I tried to adjust the idle screw (big screw under the carbs) but could not get to it properly due to fat hands.

I then adjusted the throttle cable adjustment nut until it idled correctly.

I am now adjusting the air screws.

Two questions:
1. I remember reading that adjusting the throttle cable was not a good idea, Is this ok to do?
2. The best way to determine if the bike is running rich or lean

Thanks

 

[indyjoel]

found the thread that talks about it

 

[almarconi]

Two questions:
1. I remember reading that adjusting the throttle cable was not a good idea, Is this ok to do?
2. The best way to determine if the bike is running rich or lean

1. I can't imagine where you would have read that. A mis adjusted cable could be downright dangerous. The throttle cable must be adjusted for the proper amount of play. The manual for your bike will specify the amount and the procedure. If the cable is not adjusted properly, getting the bike to idle will be difficult. Turning the bars side to side may cause your engine rpms to increase.

2. One method is to use plug chops, another is to use a morgan carbtune. With the proper setup you could also use a wide band air/fuel gauge.

tried to adjust the idle screw (big screw under the carbs) but could not get to it properly due to fat hands.

Thats what kids are for.

 

[Suzuki_Don]

found the thread that talks about it

How about sharing the thread with the rest of us Joe.

 

[Nessism]

The idle must be set with the idle stop adjuster, and when the throttle linkage is on the idle stop, the cable should have enough slack to allow the throttle grip to turn a few degrees without moving the linkage.

 

[trippivot]

does the idle go up and down when you turn the bars?

it will until you get those carbs adjusted right.

people do die on these murder cycles. I want to remind you of this fact.

get it right

 

[waterman]

does the idle go up and down when you turn the bars?

it will until you get those carbs adjusted right.

people do die on these murder cycles. I want to remind you of this fact.

get it right

I had thought that the fluctuating idle was caused by the throttle cable being incorrectly routed through the frame. It does make sense that if the cable is used to hold open the throttles that you could experience some unintended accelerations.

I agree with others, adjust the idle knob not the cable adjusters. If your hands are too large, try using a pair of pliers or even a screwdriver to turn adjustment knob. Turning knob in or clockwise will increase speed, most likely the direction you need.

Tuning involves several steps, usually you want to thoroughly clean carbs (as you have done), making sure to check float levels and / or fuel levels. Check and adjust valve clearances. Adjust air screws to obtain highest maximum idle on each cylinder, and then a carb sync to ensure that all carbs are feeding engine equally. I know this is a fairly large list, but for best reliable performance it is a must.

 

[indyjoel]

sorry been trying to fix the thing.

What I meant to say is that I could not start the bike after I cleaned,dipped and check the butterfly's, and adjusted the air screws.

I then tried to adjust the big idle screw between the carbs and could not turn it.

Then I adjusted the throttle cable adjuster connected to the top of carb 2.

The bike then started but revved around 2K. Managed to get that down to 1.5.

I went to tighten the nuts on the throttle cable adjuster but could not get them right.

The bike would not start again until I again adjusted the throttle cable adjuster. I can get it right on too around 1.1 to 1K but cannot manage to lock it down.

I dont think there is a leak (air of fuel) but I need to lock down the two screws correctly or else when I rev it the throttle cable will not come back effectively

PS I am looking for the other thread I mentioned

 

[almarconi]

The throttle cable adjuster usually has 2 nuts on it, mine are 10mm. Use two wrenches to hold one nut and tighten the other. When you open the throttle you want it to snap fully closed when you release it.

Why can't you adjust the idle knob? Will it not turn or you can't get your hand on it. I've got large hands and can turn it pretty easily.

You have to fill your fuel bowls the first time you try and start the bike. Leave the tank on prime a few minutes. A small shot of carb cleaner into the airbox will get it going.

Did you do a bench sync on the carbs after you put them together? When you turn the idle knob you should be able to see the butterflies open if you assembled it correctly.

 

[indyjoel]

Why can't you adjust the idle knob? Will it not turn or you can't get your hand on it. I've got large hands and can turn it pretty easily.
Big hands, will try again. Unfortunaltly I need to fix the two screws and then try the idle screw again. I do remember checking that the idle screw adjuster worked ok when I had the carbs on the bench.
You have to fill your fuel bowls the first time you try and start the bike. Leave the tank on prime a few minutes. A small shot of carb cleaner into the airbox will get it going.
The bowls are full and have gas in them. I checked by opening the bottom screws to make sure.
Did you do a bench sync on the carbs after you put them together? When you turn the idle knob you should be able to see the butterflies open if you assembled it correctly.
I think I will need to bench check them again. I checked when they were on the bench if the butterflies opened correctly. but cannot remember if the spacing was correct.