carb adjustments

[ltl]

I am working on an '87 Venture Royale and need advice on carb adjustments.

The bike has been in storage for a number of years and I am trying to resurrect it. The gas tank has had sealer treatment, installed new oil, antifreeze, plugs and battery. I removed the carbs from the bike and soaked them in carb cleaner.

The problem is that I can only make it start using the choke. Pushing the choke off stops it from running. Also turning the throttle stops it. Plugs are wet with gas but they do spark.

I have reinstalled the carb bank, pulled it, reinstalled it numerous time checking different things and still can't make them work.

 

I have searched a bit but can't find a procedure for any adjustments except for float height. I removed, cleaned and reinserted the jets in the jet block. Do they need to be adjusted? I've probably put something back together wrong but right now I have no clue.

Any advice would be greatly appreciated

 

ltl

[GolfVenture]

1) New fuel filter

2) Air Fuel mixture of 2 and ½ turns out.

3) Does your fuel pump click several times fast then slows down and stop clicking. Maybe your fuel pump needs replacing?

[ltl]

Thanks for the reply.

Yes, new fuel filter and yes fuel pump is working. Carb bowls get full.

The air fuel mixture screw is what I need to know how to do. Where is it!?

[GolfVenture]

On my 89 VR, the brass plug had to be drilled out. I do not know if all are that way, but I've read about others who had to drill that plug so a screw driver could get to them. I'll see if I can find a picture of it.

 

Maybe some else who knows more about it may already have a picture to post.

 

I'm at work now, but will look in my picture folder.

[van avery]

Have you sprayed starting fluid around the carbs and intakes and see if idle increases? You might have a bad vacuum leak. There are Orings under the intake boots that can go bad mine ran better after being replaced.

Make sure the carbs are all the way down in the intake boots.

Have you removed the YICS system and installed plugs and are the vacuum plugs in good shape ( all 4) ? The center two are hard to get to but if they are off it makes a big difference.

You said you soaked the carbs in cleaner. Did you blow thorough all the passages to make sure they are open?

Are the carb diaphrams in good shape and sliders moving smoothly.

If you can get it running without the air filter look down and see if the sliders are moving about the same.

Have you sync'ed the carbs? Should be seeing around 9 to 9 1/2 inches of vacuum.

Have you replace the plugs and maybe cut off about 1/4" of the spark plug cables at the coil ends they can get corroded.

Hope some of this helps. Good luck:thumbsup:

[ltl]

On my 89 VR, the brass plug had to be drilled out. I do not know if all are that way, but I've read about others who had to drill that plug so a screw driver could get to them. I'll see if I can find a picture of it.

 

Maybe some else who knows more about it may already have a picture to post.

 

I'm at work now, but will look in my picture folder.

 

As I look down at the carbs with the airbox off I see flat round silver things I think might be the screws caps. Right next to the fuel input port. I may take the drill to it just to see. Why would it need adjusting if it has never been changed? Does fuel or air go through it and can it get clogged?

Thanks!

[ltl]

Have you sprayed starting fluid around the carbs and intakes and see if idle increases? You might have a bad vacuum leak. There are Orings under the intake boots that can go bad mine ran better after being replaced.

Make sure the carbs are all the way down in the intake boots.

Have you removed the YICS system and installed plugs and are the vacuum plugs in good shape ( all 4) ? The center two are hard to get to but if they are off it makes a big difference.

You said you soaked the carbs in cleaner. Did you blow thorough all the passages to make sure they are open?

Are the carb diaphrams in good shape and sliders moving smoothly.

If you can get it running without the air filter look down and see if the sliders are moving about the same.

Have you sync'ed the carbs? Should be seeing around 9 to 9 1/2 inches of vacuum.

Have you replace the plugs and maybe cut off about 1/4" of the spark plug cables at the coil ends they can get corroded.

Hope some of this helps. Good luck:thumbsup:

 

Haven't tried the vacuum test. Vacuum plugs are in place and carbs are in boots with the bands tightened. I used canned air on the jets and passages. Diaphrams are in fair shape and do move. I haven't got to syncing yet and plugs are sparking (the two I tried). Shouldn't I be able to get it to start and idle regardless of diaphram and sync issues?

ltl

[Neil86]

You shouldn't have to worry about YICS system this was used on the 1200's (83-85).

 

You might verify you have spark on all 4 cylinders....some ignition component failures

take out 2 cylinders.

 

The brass caps are external facing out just above the drain hose bracket.

Approx vertical centerline of diaphragm cover and just below it. They are approx pencil eraser diameter with a small hole in center....yours might be gone.

Edited August 22, 2014 by Neil86

[GolfVenture]

Here is a picture of the location of the Fuel air mixture screw. Screw in until it just seats. Do not put extra pressure, just as it seats stop. Then turn OUT of 2.5 turns is recommended from the point of seat.

 

Of the 4 screws to the cover of the diaphram, locate the bottom 2. Pick a point about 1/2 the distance of the 2 screws. Then directly below that point about 1/2 inch you will see a hole and there is a screw inside.

 

If yours is solid like mine were, then you will want to carfully drill it out.

 

I believe there are some members that know the exact drill side and how much to drill in to uncover the opening. Maybe you are lucky and yours is already accessible.

[ltl]

Found 'em! Tomorrow morning I'll be drilling and screwing whether she likes it or not.

 

ltl

[Venturous Randy]

Found 'em! Tomorrow morning I'll be drilling and screwing whether she likes it or not.

 

ltl

 

Do not put a lot of pressure on the drill bit as you do not want the drill bit to hit the adjustment screw when it breaks through. I thought I had better say something as you seem pretty excited about the drilling and screwing part.

RandyA

[ltl]

I'll be just like your favorite dentist.

 

ltl

[Prairiehammer]

As I look down at the carbs with the airbox off I see flat round silver things I think might be the screws caps. Right next to the fuel input port. I may take the drill to it just to see.

NO! Don't drill and remove THOSE caps. Those are staked plugs to the float valve seats.

As Brian and Neil have stated, the pilot adjustment screws are in a deep well, cast into the carburetor body, located at 6 o'clock below the diaphragm covers.

 

Why would it need adjusting if it has never been changed? Does fuel or air go through it and can it get clogged?

The pilot screws (or as some call them the idle mixture screws) meter a fuel/air mixture for the idle to mid throttle range of engine operation. The passage(s) that this mixture passes through are tiny and convoluted and yes, this entire circuit can be plugged.

Since you did not remove the pilot screw anti-tamper plugs, you of course did not remove the pilot screws and thus, despite your soaking the carbs, you most probably did not get the pilot circuit clean.

 

[Venturous Randy]

Kevin, that's a great picture. I may try to save that for future reference on here.

ltl, try setting your idle up to see if that will help stabilize things. Also, these bikes are very sensitive to spark plugs and run good on cheap Autolites that are available at most auto parts stores. If you change your spark plugs, try to blow air around the plug first to blow out debris so you don't get stuff in the cylinder.

Also, with having the carbs apart and removed from the brackets, there is no telling how bad they are out of sync. This may be your biggest problem.

RandyA

[Condor]

When drilling the caps, remember they are very thin and it doesn't take much. After drilling a hole with an 1/8" bit, the best thing to use to remove them is a small wood screw. Screw it into the hole until it bites. Then take a pair of pliers and pull the cap off....

[videoarizona]

Kevin, great picture..thanks. I printed that sucker! Should be a sticky in the tech section, me thinks...

[Prairiehammer]

That great annotated picture of the carbs was first posted by Mike Brood (mbrood) here back in 2012.

Credit where credit is due:

http://www.venturerider.org/forum/showthread.php?t=69490