88 venture carb sync question

[Yammer Dan]

If he would just listen to his old man.

RandyA

 

 

 

Do they ever??

[masterofyard]

I took all 4 carbs apart. Removed the jet block, took out rubber caps and cleaned them out. All diaphrams are in good condition with no pin holes. Like I said, the bike while idle with out the choke on, not like when I first got it, having to leave choke on full for it to run. Now when I try to open the throttle, the bike dies. I am pretty sure the original owner played with the sync screws.

[MiCarl]

Where are the idle mixture screws? I didnt see any ones on the carbs themselves, unless there is a plug that has to be removed to get to them.

 

If you don't know where they are you didn't take them out and your carburetors certainly are not clean.

 

Dingy's post tells you where they are.

 

You need to pull the carbs again and get the plugs out. I like to drill a small hole and run a screw in so I have something to grab to pull on them. Be careful you don't go charging through with a drill and damage the screws underneath.

 

I like to put a punch mark on the carb body lined up with the slot in it's screw. You can also scribe them. A marker is likely to get washed off when you clean.

 

Gently turn each screw in until it lightly bottoms, counting the turns and fractions relative to your mark. Record these so you can put the screws back where you got them. Do not force the screws tight as they have a needle tip that will bind and ruing the carb body.

 

Under each screw is a spring, flat washer and rubber o-ring. I use a bent piece of steel wire (wire brush bristle) to fish them out. When you reinstall you put the pieces on the mixture screw and the o-ring will hold it all together while you insert it in the carb body. Tighten down gently then back out to the number of turns you wrote down earlier.

 

It's important to completely disassemble the carburetors (except the throttle butterflies) and spray carburetor through every passage, making sure it is open. Then blow out with compressed air. Do not soak the carburetor bodies in a bath of cleaner. There are o-rings on the butterfly shafts that the cleaner will ruin.

 

You also need to remove the jets from the jet block and make sure they are clean and open by shining a light through them. Do not dig at them with any kind of wire because you can damage the orifices.

 

Do the carburetors one at a time so you don't interchange any parts.

[masterofyard]

The only thing I didnt do was to remove the brass plugs. All the rest was done. I will remove the carbs again and give it another try.

[Lil Venturous]

Brass plugs maybe the mixture screws they are talking about. I believe you can remove those without removing the carbs from the bike.

 

But if you are removing carbs hold them up to a light without the diaphrams in and sync your cars that way. Just set them where the same amount of light shines through. after that several of times I barely changed them after hooking up my sync tool.

 

Did your remove the jets from the block or clean them with them in. Believe me when I say you need to remove those jets to clean them. Very tiny orifice.

 

My carbs still had the plugs covering the air screws and found from the factory one of the screws were bottomed out. Anyone else ever had that happen?

 

Can someone post some pics of the plugs under the diaphram caover and maybe the small jet in the jet block?

[MiCarl]

 

My carbs still had the plugs covering the air screws and found from the factory one of the screws were bottomed out. Anyone else ever had that happen?

 

I've seen it. The bike I saw it on I believe was factory (not a Venture though). Many carb kits come with replacement plugs though, having plugs doesn't guarantee it wasn't messed with.

[twigg]

Brass plugs maybe the mixture screws they are talking about. I believe you can remove those without removing the carbs from the bike.

 

But if you are removing carbs hold them up to a light without the diaphrams in and sync your cars that way. Just set them where the same amount of light shines through. after that several of times I barely changed them after hooking up my sync tool.

 

Did your remove the jets from the block or clean them with them in. Believe me when I say you need to remove those jets to clean them. Very tiny orifice.

 

My carbs still had the plugs covering the air screws and found from the factory one of the screws were bottomed out. Anyone else ever had that happen?

 

Can someone post some pics of the plugs under the diaphram caover and maybe the small jet in the jet block?

 

lol ... I dream of the day when I will buy a bike that has the carbs undisturbed like that

 

You are correct, it is only necessary to remove the fairing lowers on the 1st Gen to access the mixture screws .... You can replace the diaphragms like that too. The carbs only need removing if you have done everything you can with them in place, and it still doesn't run right.

 

Having said that ... It's a tricky job first time, which gets easier with practise. The cables are the biggest pita. To make it easy you have to remove the left upper fairing ... not a long job, but a nuisance.

[dingy]

This picture is best I can do right now, PC issues on desktop.

 

The screw circled in red is the left side sync screw, opposite side has 2 screws in same vicinity.

 

The yellow circled hole on right lower side is one of four idle mixture screw holes. Brass plug has been removed.

 

The idle adj screw is below the bar at the bottom of this picture, but not seen.

 

2nd picture shows parts from inside the jet block, positioned below jet block, float and float needle valve & main tube also in picture.

 

You have mentioned several times that you think PO messed with sync screws. It doesn't matter. When you split carb rack apart they almost for sure needed reset.

 

The sync being out a little is almost for sure not going to make it die when throttle cranked, unless you didn't get them close on bench setup. But they would have to be wayyy out.

 

Gary

[bkuhr]

I might suggest that while carbs are out again the you preform a fuel float level check, while on the bench.

[Lil Venturous]

Thanks Dingy. that is what I was hoping for. That little jet on the left needs to come out and cleaned out. Don't drop it either. Tiny hole.

[MiCarl]

I might suggest that while carbs are out again the you preform a fuel float level check, while on the bench.

 

+1.

 

And since the mark you measure to is on the float bowl you might want to put a mark on the diaphragm cover so you can check them without removing the carbs next time.

[masterofyard]

I took the carbs back off, drilled out the caps...cleaned everything out again including the jet block. Everything is clear. I am going to put carbs back on tonight and see what happens. I will update tomorrow morning.

[masterofyard]

ok, put the carbs back on, now the bike starts, but bailey runs on choke. when i take it off of choke, stalls ut and I cant even give it throttle, stalls right out.

[bkuhr]

check fuel float level

[cimmer]

Not sure if it will help or if you have them already, here is a link to the post with a link to the service manual for the 1300 Venture.

http://www.venturerider.org/forum/showthread.php?t=3384

Hope that helps.

Rick F.

[MasterGuns]

Shawn,

 

Gee, I wish I were closer to ya; I'd just ride over and see if I could assist with your carb issue.

 

Maybe someone reading this post that lives nearby could do so.

 

Good luck with all the recommendations from other members.

 

In my opinion sounds like your problem is mostly caused by the carbs being way, way out of sync.

[masterofyard]

thanks for the offer, I am to the point of looking for a new set of carbs. This is very frustrating.

[goatman123]

Try to locate a carb sync tool and see where you are with them. I posted earlier in this thread because I had the same running issue, it would run on choke, run barely on no choke, and try and give it throttle and it would die. That sounds just like yours. All that was wrong with mine was the carbs were out of sync. I did a bench sync using the "eyeball it" method to get the amount of light showing to match at each butterfly, so I didn't think that was going to be my main problem, but it was. This may not be your issue, but I had the exact same problem you are having, and all it needed was the Carbtune. It's worth a try before tearing it apart again.

[Abbe]

With the airbox off, check visually that the butterflies open and close as they should. Use a very thinn piece of metall string to adjust the sync screws and butterflies to match. That's a good start to begin syncing if things been tampered with too much...Note that the "idle screw" must be used to adjust carb 2 butterflie. After above, when you start to truly sync with a sync tool, keep the idle up or down with the idle screw after every adjustment!

[Yammer Dan]

Sync them.

[mmaleney]

Thing is there is no new carbs only used carbs and the new ones you get may have been siting on shelf for a year or so I know because I have three sets sitting on my shelf all needing work and new parts , you may be better off working with what you have or finding someone who has can clean carbs with an ultra sonic system, the cost should be round $200

[masterofyard]

I am at the point where the bike wont start now. I have a friend who has carbs from a 1984. Will theses work on my bike or what has to be changed so the will work?

[dingy]

They will work, kinda of.

 

The 83-85 had 34mm carbs, 117.5 main jets, 42.5 pilot jet.

 

The 86-93 had 35mm carbs, 125 mains jets. 37.5 pilot jet.

 

Externally the 84 & 88 carbs are identical. If they are in usable shape, they will run the bike, though not to its full potential.

 

Putting another set of carbs on the bike may narrow down the cause of your problems, assuming bike runs well with the 84 set. It does not address why a set of carbs that have been rebuilt properly do not run the bike.

 

There are a number of things that have been suggested in the course of this thread that you have not responded to as far as your findings or corrective actions. Without this feedback, we are hampered with helping with a course of action. You are far from the first to have this happen, but there can be more than one contributing cause. Without each item being responded to, it is hard for us to help you. There have been two of the top mechanics on this site for the 1st gens (MiCarl & Skydoc_17) make suggestions to pursue.

 

Gary

[masterofyard]

I had the bike running after cleaning out the carbs, onky problem was that I couldnt give it any throttle, the bike would stall out. It was suggested to remove the brass plugs and set the mixture screws to 2 turns after being scewed all the way in. After that procedure, is when the bike wont start at all now. I dont know if it has anything to do with the playing with the mixture screws or what it is. I am at a dead stop trying to figure this out.

[frankd]

How many turns were the idle mixture adjustments open when the bike would start??