Single Carb Conversion 2 Barrel Progressive Holley,Weber 740 carb

[westgl]

Dan, Yes of coarse,

We all know this is your prototype, you will work on it, and get it the way you want it.

You have proved to your self it works, now you can improve up on it, and make it better.

Did you shorten the Throttle cable?

I like that Cable stop you made.

I may look at that for mine.

 

[westgl]

Dan,

While on your test ride please provide a thought in regards to the throttle pull.

and the Throttle pull length, or the smoothness/harshness of the shorter throttle length of pull.

When riding normally is the throttle length of pull at all abrupt? or uncomfortably fast, if ridding normally, like cruising, and speeding up.

Your thoughts on this?

 

[dan filipi]

I used a spare cable I have.
It's a universal that was too short for the stock rack.

 

[westgl]

If nothing else a decent stock rebuild-able Carb rack is worth at least $125.00, local cycle salvage price and have seen them on Fleece bay for that price.

That is some money toward the new Single, to offset the cost of singles carb. conversion.

A $100. off the price of the Single conversion is better than a poke in the eye with a Sharpe stick

 

[dan filipi]

Ride report:

westgl » Fri Sep 20, 2013 12:19 pm[/url]":3336k1oq]
Dan,

While on your test ride please provide a thought in regards to the throttle pull and the Throttle pull length, or the smoothness/harshness of the shorter throttle length of pull.
Pull length is good. I like how it is. Very close to stock.


When riding normally is the throttle length of pull at all abrupt? or uncomfortably fast, if ridding normally, like cruising, and speeding up.
Not at all abrupt or too fast.

Your thoughts on this?
Throttle pull effort is easier than stock.
I expected pull would be abrupt and come on too soon but it feels good.
If throttle had come on too quick I had a plan to extend the attachment point (easy deal) at the carb for a longer arch to solve that but I like how it is.

Ok with those questions answered.....

I ran around city streets and had a chance to open it up to 60 mph or so but had to slow right down.
No freeway run yet.

It bogs real bad under load.
Starting from a stop I have to slip the clutch a lot and keep the revs up high to take off otherwise it will bog.
When moving, I have to accelerate slowly or it will bog.
If I'm say.... in 2nd gear lower rpm then give it 1/2 throttle, it will bog bad then engine power will "catch up" and take off.

Wide open throttle sounds cool.

Wide open:
One time it backfired up through the carbs at least 3 times.
One time it felt as if it was surging or miss firing, I'm not sure which.

Back in the garage:

Idle sped up a few hundred rpm's, slowed it down with a 1/4 turn.
Checked for vacuum leaks. 2 fittings are leaking on the hose going to #4 cylinder. Not bad and not more than they were. The others seem ok.


I expected the backfires to blow my hoses apart but they held :smilie_happy:
This is fun stuff. Reminds me of when my brother and I were trying out various vapor carburation builds 30 years ago.

When I got into the garage scratching my head thinking what to try next lol, I noticed there are 2 carb base gaskets came with this carb.
The one I have installed does not have these cutouts.

Could it be the bog is caused by a fuel channel being blocked off?
Will have to pull the carb and check this.

 

[westgl]

Well,

That is not as good of a ride report as i was hoping for.

I wanted to hear it runs perfectly, Just as Mine does.

I would start by getting rid of all Vacuum leaks as you cannot start doing any tuning until that is cured.

A few here & there they all add up.

you could be backfiring, from the running rich & vacuum leak

The Bog must be your over rich condition.

Slow to rev and slow fro RPM's to drop back down, & reduced power is a Vacuum leak.

I have talked to Tom, about jets he said, he had some jets, even if they were large then what you have, they can work, pull the ones you have compare them to the new jets, then solder the new larger jets closed, drill the new jet with a slightly smaller hole size.

Lets talk about Where your Bogging is, Think about that, and maybe ride it again, and be thinking where the bog occurs.

This carb has different circuits that work independently from each other, ie: idle circuit, off idle circuit, Main jet circuit/ high speed

also
Next time you have it running & checking for vacuum leaks also spray the throttle shaft
it also could be leaking as you are un sure of how much wear is on that carb.

The way to check for worn throttle shaft bushings is any side to side movement.

I assure you, my New Carb from Tom runs perfect right out of the box.

 

[westgl]

That gasket could be for some sort of venting?

I dont know?????

 

[dan filipi]

I assure you, my New Carb from Tom runs perfect right out of the box.

Yes well I had already received my carb before I knew about this Tom guy so moving forward........

 

[joedrum]

well I have to admit it took me a day or two to get things right as it was all new territory for me ...its a shame when others sponge through our topics to bash else where ...and attempt to discredit our topic and goal ...so for awhile we have close the circle down to keep the BSpeople away that just bring something down as oppose to help ...

yes im sure it will work as westgl did it is a different carb but not by much ...its nothing more than dialing in is all

sheesh most people die right here in there effort or never advance over it

to me the type 4 is perfect base piece to use that all can easy get ....it is almost part of the carb itself ..if tought of that way it can be tuned as a carb adjustment..

In all the yrs ive followed this I see nowhere this is brought up ....yes it is running to rich ..but more properly put it not atomizing the gas at a good enough clip for the motor not to bog ......

as stated before in threads over the yrs people say advancing timing curve helps ... some but not really....

I will tell you a fact if you increase the speed of the air right at the manifold the carb will start to react faster and keep up with motor ....the type 4 is such a perfect base to do this ....

if this is done just right you will get good flow through carb and still have right flow ...for secondary ...plain and simple ... ive been trying to get this point across ....

this manifold was made for a VW ...that dosent mean oldwing ....it is better suited to that ...to think that nothing needs to be done here is somewhat foolish ...and to say all oldwing motors are the same after 30 plus yrs of service is also foolish ... so lets get real here

this is a good starting base ... and anyone who starts here will get success is the best thing to say ...

its obvious the problem is at the carb and maybe vacume leaks .... but it has nothing to do with the runners make up as captian discount says ....

we are doing fine here in my opnion and we will cover all things and it will be running great soon :mrgreen:

 

[Ansimp]

westgl » Sat Sep 21, 2013 4:47 am[/url]":2mpvk50e]
Here is a Picture of my GL11-S,

It does look less complicated than with the 4 carb rack.

That windshield has a quick release on it, takes 15 seconds to remove the shield and go to Naked

Those are HD mufflers, it sounds really nice with the combination HD mufflers and the new Single carb. it is Not loud! I dont like loud and obnoxious, I like a nice deep throaty sound, that is comfortable sounding, the HD mufflers are Stock and are NOT modified.

That is my 58' Corvette in the back Ground,

and my 1967' Chevy pickup, w/ new 350ci V8 & new 4speed auto.



Both have been completely Gone through

Could someone please take their single carby modded bike for a strap through some twisties and some heavy braking etc. I am concerned that you may experience leaning/ enriching of the mixture etc. the main reason for using cv carbs are they are not as effected by attitude changes as a conventional down draft carby. :thanks:

 

[dan filipi]

Ok, where I'm off to next here is to have a good look at this carb and it's passages.
From what I reed there are a few variants of the 740 series so there may be some controls or passages flowing that shouldn't be or, some that should be.

Next I'll be sourcing new runners that can be made surely high vacuum tight.

 

[joedrum]

good point tony but I can say one thing for sure ... center mounted and low seems to have this effect as low as possible as oppose to ever expensive webers on the heads deal ... its noting but hills and curves around me and I had no trouble here at all till I went over the edge of road solo without bike thank god :shock: once pulled out it fired right up carted my butt home :mrgreen: but I don't think I ride as good as you tony so im sure I wasn't pushing like your talking

 

[westgl]

I did some fast twisties, with some heavy braking, with my bike,

My engine/bike runs flawless, No bogging, at all any where & throughout all throttle positions.

It revs really fast, and it just goes.

As far as my testing goes, the CV carb thing is a myth.

The 32DFT also has a provision for high altitude compensation.

Ansimp » Fri Sep 20, 2013 2:49 pm[/url]":3bi8ixxu]

westgl » Sat Sep 21, 2013 4:47 am[/url]":3bi8ixxu]
Here is a Picture of my GL11-S,

It does look less complicated than with the 4 carb rack.

That windshield has a quick release on it, takes 15 seconds to remove the shield and go to Naked

Those are HD mufflers, it sounds really nice with the combination HD mufflers and the new Single carb. it is Not loud! I dont like loud and obnoxious, I like a nice deep throaty sound, that is comfortable sounding, the HD mufflers are Stock and are NOT modified.

That is my 58' Corvette in the back Ground,

and my 1967' Chevy pickup, w/ new 350ci V8 & new 4speed auto.



Both have been completely Gone through

Could someone please take their single carby modded bike for a strap through some twisties and some heavy braking etc. I am concerned that you may experience leaning/ enriching of the mixture etc. the main reason for using cv carbs are they are not as effected by attitude changes as a conventional down draft carby. :thanks:

 

[westgl]

Dan

Once the vacuum leak is fixed, just fixing the vacuum leaks may cure a lot of problems.

If the engine bogs at just off idle, then we can assume, the off idle circuit is one of the culprits and do that jet first,

if there is No bogging in the Off idle circuit say up to 25-35 mph, then the off idle circuit is close to being good.

If The Bogging only occurs at higher speeds or when the secondary is opened then we can assume that the High speed main jet is at fault.

 

[82a]

The 32DFT also has a provision for high altitude compensation.

:shock: opcorn:

 

[dan filipi]

Had a good call with Joe, we went over a bunch of things.

Considering I'm running 1200 cams in this 1100 motor getting 200 lbs. compression on the right bank and 150 lbs compression on the left bank, my next move is to put the 1000 cams in.
Early 1000 cams because we already know these cams are a good bump in performance all around and the bore and stroke of the 1100 and 1000 are the same. 1200 is different.

One other thing I never mentioned in my stock carb thread is when I sync'd the carbs to within a 1/2" vacuum, it knocked just like when the 2 sides are out of sync.
When I'd moved the left bank OUT of sync by close to 4" the whole engine smoothed out and quiet down as it should be.

For me, everything is put on hold until I swap out the cams.
Hopefully this weekend then I'll continue on the single mod.

 

[westgl]

Yup!

There is a device that hooks up to one of the vacuum lines, it is in that 740 manual that i posted a link to
It is automatic, at a certain altitude, it senses the altitude change and leans the carb.

a Altitude compensator, it works at 3000ft and is off below that.

 

[Ansimp]

westgl » Sat Sep 21, 2013 10:41 am[/url]":ft71q25e]
Yup!

There is a device that hooks up to one of the vacuum lines, it is in that 740 manual that i posted a link to
It is automatic, at a certain altitude, it senses the altitude change and leans the carb.

Great to hear that the conversion is a success in the corners :good:

 

[westgl]

The corners here are hilly,

So I have the road pitching back & fourth, and up and down.

I live in deer country, I have to make sure my brakes are 100% deer are hearing animals, and travel together.

I had 6 of them run out in front of me and my Brother in Law, I was on a GL1800 B-I-Law was on my 88' GL1500, I grabbed a Heaping handful of brakes as 6 deer shot across the 2 lane Country road, up in the mountains, right in front of me from behind a bunch of trees, at least neither of us got hurt.

Problem is those deer never all go across the street side by side, and be all across at the same time, No they have to go across one after another, after another.

Ansimp » Fri Sep 20, 2013 4:49 pm[/url]":1f974jyc]

westgl » Sat Sep 21, 2013 10:41 am[/url]":1f974jyc]
Yup!

There is a device that hooks up to one of the vacuum lines, it is in that 740 manual that i posted a link to
It is automatic, at a certain altitude, it senses the altitude change and leans the carb.

Great to hear that the conversion is a success in the corners :good:

 

[westgl]

I Have said this before in this thread, I will say this again, My GL11-S,

Rivals most Fuel Infected bikes at how crisp the throttle is, and Smooth it is, in Power delivery.

It rivals Most FI bikes, It is better than some of the FI bikes I have owned and ridden, they were Brand New bikes, not 30 years olds like my GL11-S

I had a 09' Suzuki DL1000, Very Fasst Wheelie bike, easy to do a wheelie or a stoppie, that bike had a abrupt throttle, certain spots in the throttle were twitchy.

I had a Suzuki C109R 1800cc twin high power & torque, very abrupt throttle, I had to ride it all the time and take a week or two to get used to it very twitchy throttle
it was twitchy throttling up or down.

My GL1800 had a very nice FI system on it, not twitchy at all, very smooth and linear, in throttle transition.

Now I have a Honda NC700X it is by far the best throttle I have ever ridden, SMOOTH, engine SMOOTH, Trans SMOOTH, Brakes SMOOTH, handles great, Grip is great, and to date 76mpg average, with me riding spirited. Honda did this one right, it is awesome, they are saying that the NC700X is the next early Goldwing, as it is revolutionary, in design, like the first goldwings were