Clutching or idle issue

[rotorav8r]

My Argo Vanguard II used to idle and shift fine. After a month of sitting it was trying to engage and spin the belts while idling in neutral. This makes gears grind when shifting. It starts and runs well. Right now I have it idled down (via idle screw) to where it dies at idle because I’m trying to prevent the clutch from engaging. Currently I shift then re-start it wasting starter cycles. If I turn the screw until it idles up it really spins the clutches faster. It isn’t enough to move the machine but it is too much to allow smooth shifting. I’ve cleaned the carb and it is very clean. I have the manual but there isn’t much as far as troubleshooting.
I’m wondering if the clutch may be suddenly engaging too early after sitting for a month. Has anyone had this issue? Fix ideas? Does this sound like a clutch internals type of issue?

New fuel pump and air cleaner. This is the same belt the whole time. I’ve considered adding a welding rod spacer under the spring but should I have to do this when it used to work fine? Will more spring tension make the clutch engage at higher rpm? Mine is the front engine 16hp Vanguard II 6x6. Are you all removing your muffler to get the primary clutch off? It sucks it’s under the muffler barely visible.
Thanks for any help

[bigfootbob]

Sounds like a carb problem. Whats the idle rpm? Does the motor idle with the transmission in neutral. The b&s will not idle properly and tends to stall when the carb is dirty.

[rotorav8r]

I’m trying to determine the idle and a way to measure it. It seems fairly low. Do you ever see the primary engage too soon?

[bigfootbob]

Have you tried removing the belt and watching the primary clutch move in and out while you rev the engine. Maybe its stuck and not opening fully. The primary spins and squeezes the belt so if its not opening fully it would start to move the argo to early. You can use a teflon based lubricant but clean the clutch surface with brake fluid if you get any on it.

[rotorav8r]

OK, yesterday I cleaned the carb again. I have the vertical Nikki carb where you remove the top but the body is hard to remove without removing parts of the engine. I took the top off then removed the jet. I removed the plug on the bottom of the carb. I sprayed out every port with carb cleaner and compressed air. I can see light through the jet and pickup tube holes and cleaner flows out of them all. The needle’s seal and float seem good. The carb seems spotless. There is a very inaccessible screw on the side that I think may be an idle screw. It has a gray plastic tab on it preventing it from turning much. Does anyone know an adjustment method on it? Today I may remove the primary clutch. It seems to open more when the engine is off then when at idle.

[ARGOJIM]

Idle mixture screw, probably where your problem is if it hunts. Start at a 1-1/4 out and adjust from there.

[rotorav8r]

Is that plastic tab supposed to come off or anything? It prevents the screw from spinning it looks like.

[ARGOJIM]

Gently pry it off or try needle nose, count your turns of the screw on the way out to get close on reinstall.

[rotorav8r]

OK, well its all fixed. It was the idle mixture screw indeed. I couldn’t even really see it at first. Suddenly one day it wouldn’t low idle and was spooling up the primary clutch making shifting very hard. It is like butter now with NO grinding. Maybe a little bump once in a while but almost not even a thing really. Thank you for the input.

I pried that little limiter cap off then had a fun time turning it with needle nose and my fingers. I marked it with a sharpie to count the turns. For anyone reading this and going to do it...once the plastic cap is off there is no head really, no regular or Phillips head, just some knurling. I noticed the plastic arm could be snipped off with pointed wire cutters to allot it to turn past the stops then you could leave the plastic knob on and use a flat screwdriver to count the turns easily.

Procedure that worked for me: To start set the idle AIR SCREW at 1 1/2 turns out from gently seated. Have idle SPEED screw at a reasonably low speed (manual has RPM’s but I don’t have an RPM gauge). Warm engine up for 5 minutes at half throttle. Then turn the AIR screw in at an idle until the engine bogs a little keeping track of how far you turn it. Then turn the AIR screw out until the engine bogs a little. Set the AIR screw back to the middle between the two points. Readjust the idle SPEED screw. Once I did this it idled down even lower and the secondary barely rotated slowly.

Tips: You must set the idle air screw with the air cleaner on. There is a black brace that is in the way. If you remove the two Phillips screws the brace comes off then you can reinstall the air box. I have big hands and I could reach in under the air box and turn the air screw by hand. A short Phillips and flat head will be handy for this job. The airbox has 10mm bolts. I’m not sure I’m going to replace the brace. Does anyone think the little brace is required?? I can’t really see what it does unless it just supports the tin on each side. It effectively makes adjusting the idle air screw almost impossible that’s for sure.