High idle, help!

[LIV2RIDENMI]

Hi there venture riders, I am posting a thread for the first time ever and here! I have enjoyed this forum since I bought my 83' venture 1200 and now have a reason to find some help. My bike ran good but lacked full power, I took off air box and noticed left rear diaphram slide not opening. I took outside cap off and found the metal sleeve seperated from the plastic slide. I took a little epoxy and reassembled properly, diaphram looked great. I started the bike and checked operation ( all 4 working properly) it now when warm idles at 3000 rpm. Checked choke and throttle cables lubed them and saw they were operating properly. I feel this is a vacuum related issue and can't find the fix Thanks in advance for any help, this bike is my only transportation right now.

[Yammer Dan]

Have you tried to adjust idle? Big thumb screw between two left side carbs.

[LIV2RIDENMI]

Thanks for reply. No I haven't, don't understand how the idle screw would need adjusting now, idle was good before. I thought about that......... If I hold all four slides back ( not one or two) the idle goes down to 1000 rpm.

[LIV2RIDENMI]

I bought the bike last year (20k) miles and got running this year. First thing I did was take carbs off and cleaned and inspected (looks great). The carb boots look good leak tested good as well. Hold all four slides back and idle goes down to 1000 rpm, release them and they close, idle climbs to 3000 rpm. What did I change by fixing the slide issue it had???????

[Snaggletooth]

Any change.... to all the the carbs or one alone can change the idle. A fix to a diaphragm, a change to an idle circuit, a bump on the sync screws or a minor leak on the intakes can be the difference in a 1,000 RPMS.

 

There may be other issues big or small but checking the idle screw adjustment would be your best bet from the start. On the left side of the carb rack. Easy to see and adjust from below the rack body.

 

Mike

[GeorgeS]

Most likley you are going to have to get the tool, to do the Carb Sync Proceedure.

 

First thing to check is, #2 throttle plate, make sure its going from " full closed " to " full open "

Check the pull cable, make sure it has some Slack ( about 1/16 to 1/8 inch ) before the plate starts to open.

 

(( see service manual page 2 - 14, " Throttle Cable Adjustment " proceedure steps 1 thru 8 " ))

 

Now check the other three plates. Make sure they are all in the same position, ( full closed )

Check the Service Manual, for above adjust ment proceedure, its all called out there.

 

Then go on to the Carb Syncing proceedure. ( also in the manual )

(( see service manual page 2-12 to 2 - 14 ))

 

Be sure to get the Cables, adjusted properly first, with the slack adjustment, to #2 carb, ( the master ) THEN, go onto doing

the Sync proceedure of the other three.

Most likly, sombody has been " Messing With "" the three SYNC Screw, and one or more of them is " Way Out of Wack " As they say.

This is very common on these bikes,

 

Manual is avialable on this web site, if you do not have one, ( See VR Tech, left side menu from Home page )

Edited April 23, 2012 by GeorgeS

[Condor]

Most likley you are going to have to get the tool, to do the Carb Sync Proceedure.

Manual is avialable on this web site, if you do not have one, ( See VR Tech, left side menu from Home page )

 

I tend to agree with George. I sync is in order.

BTW which carb diaphragm did you repair??

[Yammer Dan]

Sync them.

[LIV2RIDENMI]

Thanks for ideas. I will try the idle screw even though i doubt it will help. I also would like to sync the carbs which i have never done and any info is much appreciated. I will try idle screw now and let you guys know how it goes!

[LIV2RIDENMI]

Thanks guys ! I don't understand it but backing off on the idle screw and some cable adjustments got me idling again at a 1000rpm. Now i have to sync this puppy. Any suggestions would be great!

[Coffeepot]

You could try searching for one of the numerous threads on the subject of carb synchronization on this site. There are many different tools and methods available but I'm sure someone with the "correct" procedure will chime in soon.

[KIC]

PM me an email addy and I will send you a word document from one of the threads here.

 

Also, start a thread asking if anybody near you has a CarbTune. I just ordered one from the manufacturer.

[skydoc_17]

Hey Wayne,

Congrats on posting your first thread! The $12.00 you spend to join us will be the best money you have spent in a long time, I assure you.

Check out this thread on Syncing the Carbs. on your "new to you" VR. It is from the Tech Section of this forum:

http://www.venturerider.org/forum/showthread.php?t=56723

 

The reason your idle jumped up after you fixed your Carb. Slider is because before the fix, your bike was basically running on 3 cylinders! The previous owner cranked the idle up to 1000 RPM's after the slider failed, and now you have returned it to the proper position when ALL 4 cylinders are operating properly. Here is a link to the company that makes a Manometer that is Mercury Free, and functions pretty well, plus you can connect all 4 Carbs. to it at the same time for the sync.

http://www.carbtune.com/

 

Now, a good set of Mercury Sticks will set the Sync. a bit closer, but these Mercury Sticks DO NOT travel well, and if you use them much above idle, you run the risk of sucking the Mercury into the intake manifolds. The Morgan Carb. Tune is easy to work, travels well, and is close enough to get the job done, without all of the risks related to the Mercury Sticks.

Keep asking questions, and keep us posted on how your bike is running. By the way, you may want to throw a new plug in that cylinder you just repaired. (if you are feeling frisky, replace all 4) The NGK DPR8EA-9 is the plug Yamaha uses on these V4 motors.

Earl