High idle at times?

[Irv]

Fired the sled again today (08 Vector, carbed) and I am curious about something?

When the sled is warmed for a few minutes and throttle is applied, why does it not always return to a normal idle?

I believe my normal idle is around 1500rpm but sometimes it stays around 2100-2300rpm when I let off the throttle.

It will sometimes return to the 1500 rpm on it's own but it may take a minute or 2 before it does and other times I have to tap the throttle a few times or give it some revs before it does?

I assume my carbs are out of sync and my idle needs adjustment?

Any info would be appreciated.

Thanks

 

[smalltownpower]

pilot jets are plugged. i had to rip my carbs off 3 times to get it to idle. i then had to remove my fuel screw and clean that passage way out. blow carb cleaner in every crevise and watch where it comes out. if it dont come out of somewhere somthins plugged. when cleaning pilot jets dont go over to your torch and get the tip cleaning rods, instead get a some #10 wiring and strip back 2 inches of it, and use 1 or 2 strandss of the copper to clean out the jet.

 

[RXMax]

I believe it more so to do with vacuum and this style carb. The slides hang open from a little too much pressure. You might try a set of holtzman CV springs to achieve a different pressure.

 

[03RX1-ER-LE]

pilot jets are plugged. i had to rip my carbs off 3 times to get it to idle. i then had to remove my fuel screw and clean that passage way out. blow carb cleaner in every crevise and watch where it comes out . if it dont come out of somewhere somthins plugged. when cleaning pilot jets dont go over to your torch and get the tip cleaning rods, instead get a some #10 wiring and strip back 2 inches of it, and use 1 or 2 strandss of the copper to clean out the jet.

X2

 

[Gone Blue]

I fine that even with clean pilot jets my idle still hangs a bit. G.B.

 

[canadianhunter]

On our sleds it depends on the idle speed setting. I have my idle at about 1450, an 1/8th turn more and they hang up. It seems that I am stuck with 1450.
Carbs are clean, this has been the case since new.

 

[grizztracks]

I've found that setting the idle to high will cause it to hang at higher rpm's after releasing the throttle. Lower the idle to around 1400 and I think you'll find it settles much faster. Also, many people neglect having the carbs re-sync'd. I've cleaned many carbs and always find them out of sync after reassembly so I recommend periodically checking them.

 

[Irv]

I've found that setting the idle to high will cause it to hang at higher rpm's after releasing the throttle. Lower the idle to around 1400 and I think you'll find it settles much faster. Also, many people neglect having the carbs re-sync'd. I've cleaned many carbs and always find them out of sync after reassembly so I recommend periodically checking them.

Basically what I was thinking, they need to be sync'd.

Is there any links/pics that show the step by step process? I have done my XLT before but the carb set up on my Vector looks a little more complicated?

I also only have 4800 km's (3000 miles) on it and run Sea Foam through it quite regularily so I have my doubts the jets are plugged, but I could be wrong?

Thanks for all your help

 

[grizztracks]

I made my own sync tool out of 12' of 5/16" vinyl tube filled with a little transmission fluid. I mounted the tube in a "U" shape on a 4' 1X4 pine board and filled it so I had around 20" of fluid in each side of the "U". You can only sync two carbs at a time but I've had good results with it. #3 carb (stator side) is preset so you sync 1 and 2 to it. There are only two screws to adjust which are located between 1-2 and 2-3. It's an easy adjustment that can make a big difference in performance. I'll be doing a Vector tomorrow and will get some pictures.

 

[Irv]

I made my own sync tool out of 12' of 5/16" vinyl tube filled with a little transmission fluid. I mounted the tube in a "U" shape on a 4' 1X4 pine board and filled it so I had around 20" of fluid in each side of the "U". You can only sync two carbs at a time but I've had good results with it. #3 carb (stator side) is preset so you sync 1 and 2 to it. There are only two screws to adjust which are located between 1-2 and 2-3. It's an easy adjustment that can make a big difference in performance. I'll be doing a Vector tomorrow and will get some pictures.

Thanks Grizztracks, that would be great!

Any thoughts on air-mixture screws? I recently read somwhere where a peep adjusted his and they were all out? He stated he set them all to 2 full turns out and it made a big difference.

What's your thoughts on doing this as well, are they that far out from the factory?

 

[grizztracks]

I've never had to go that far. They are preset by Yamaha and normally don't need adjusting, A good cleaning and resyncing the carbs has always corrected any problems I've ran into.

 

[grizztracks]

Irv, here are a few pictures of my Carb Sync Tool and it being used to sync the carbs on a Vector.
Note: never run the engine with only one side of the sync tool connected or you'll suck the oil out of the tube.

Carb sync (tool connected for #2 adjustment)

Carb #2 out of sync

Carb #1 slightly out of sync

Sync'd carb

 

[stomper]

Cool set up. I love home made tools. I have never synced cars before, what port on the carb are you hooking the tubing to?

 

[grizztracks]

carb #3 has a cap on the vacuum port and is preset (stator side). You sync the other carbs to #3 so one side of the sync tool remains connected to #3 vacuum port (capped port). The other two carbs have vacuum hoses that run to the fuel pump. You remove the hose at the carb being sync'd and hook the other side of the carb sync tool to the carb port. The pump vacuum hose is reconnected to the tee in the sync tool line as shown in the picture. After the carb is adjusted shut down the engine and move the lines to the next carb to be sync'd.

 

[VectorLTX2012]

This should be a "sticky".

Chester