New guy, another single carb conversion.

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Hyde

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I was recommended to this site by another site for the wealth of single carb knowledge here. Unfortunately Im pretty far into the process already and reading some things here that worry me a bit.

So long story short early this year I bought a single carb manifold and carb locally, the manifold is the one I will be attempting to use and the carb was a new EMPI that had dismal results. I shelved the project, got it rideable with the stock carbs and put quite a few thousand miles on this summer. My carbs have seen better days like most, and are part JB weld and a lot of RTV at this point, combined with some runability issues I decided to revisit the single carb.

After much (but apparently not enough) research I pulled the trigger on the 32dft from Langdon, he stressed the idea of heating the intake which I have started the modifications for, now seeing the ideas on here Im not sure if mine will work sufficiently. So could I get some feedback on my plans I have going?

Adapter for the Solex manifold

Heating "grid" which is JB welded to the bottom of the manifold which I sanded to bare metal

Heat wrapped, will be sprayed with black VHT

Coolant coming from the crossovers, not sure if I thought this through but the elbows are cheap if it doesnt work out
 
If the carb is dialed in correctly heat is NOT needed. For best power you want atomized fuel. The mist carbs are supposed to provide. Not vaporized fuel. Heat vaporizes the fuel. Read through this thread. viewtopic.php?f=107&t=10513#p160665 Long read but worth it for your plan.
 
I watched a vid on youtube the other day said the key was soldering the hole in the butterfly closed and turning the squirt nozzle close to the edge so it squirts between the butterfly and carb body.
said to have cleared up the poor performance, hesitation and needing to rev to launch. this was on an aftermarket 34 pict by the way..may be similar with other carbs.
great vid and very detailed, I`ll link if I can find it, Jersey accent,living in Georgia ,aspencade 1200
[video]https://youtu.be/q-tAuASdByQ[/video]
 
I've thought of many things to say in my reply but for now I'd say just try running it without heat hooked up then go from there. We've explored the dft extensively and can help with getting it dialed in.
 
ok the dft carb ...my bike uses the dft carb ..its not the tom carb ...32-32...but is the slightly bigger dft 32-34 carb ...they are are very close to the same ..basically air flow increase is the only difference...

there are two things i disagree with on the info tom puts out ...not saying it's wrong for car application ..just talking oldwing motor here ....

carb comes with a fuel shut off device on the idle circuit...tom says this can come off and it can ...but it seems to me when the motor is turn off the idle circuit can siphon idle circuit gas into motor down to the bowl level where idle is drawn from ....so to me the fuel shut off needs to stay on carb and wired up to work

second is there is no need to use heat on the manifold ....in fact it is best to stop the heat right at the head if possible .....

past that the dft needs mods done to it in my opinion and was necessary on my bike ....car carbs have big idle circuits cause of air conditioning and power steering and oldwing motor is small in comparison to car motors....

the dft carb also has a combined idle and off idle circuit ..this had to be separated on my carb to get to get idle circuit small enough ...

there is an epa power valve on dft carbs that's not adjustable and has to be deactivated ...

if these things are done ...past that the dft carb set up is second to nothing out there ...

my bike has instant power ..being a 2 stage progressive carb ...the carbs air flow cfm grows as rpm demands ....this also brings in the point of rpm ..on my carb the jetting passed the idle circuit is huge ..compared to stock car jets that's because the rpm capability is three times higher than car motor ..that makes for big flow even though the motor is smaller ....

so if you want to go this route ...which I'm glad i did ...you will come up with a superbike like ride that is totally reliable ..ive been on some long trips with mine ..with flawless running .....
 
As a counterpoint to the above comments; it seems like the DFT carbs work fine without heat but need to be modified from their original design to do so, the carb can be made to run well, without modification, by the use of a heated manifold as Tom recommends.

I chose the second way by running coolant through a chamber in the manifold and my bike runs great in hot or cold weather with the carb as it came out of the box (with electric choke removed). I confess I have not tried the mods that Joe has done and I don't think Joe has tried a stock carb with a properly heated manifold.

Brian
 
Hyde, you seem to be part way down the heated manifold path already. If you look at my build at "Canuckxxxx's single carb manifold build" it describes where I took the coolant supply and return from/to the engine.

Good luck
Brian
 
yes there are many ways to go after a dft carb ....brian for sure has done well with his and has been running his a long time also ....lots of good reading on classic with dft carbs ...his carb is also a tom carb ...as ,mentioned mines the bigger one ...and the air flow difference in carbs is the biggest factor on carb operation .....
 
Thanks for the replies guys, currently reading through your thread canukxxxx. My riding condition can be from 20F too over 100F depending on the time of year so icing could be a real concern. Glad I found this site though its been very helpful so far. I have noticed that most on here use the VW intake with homemade runners of some sort, has anyone used the sort of intake I am with an adapter? I think the 1bbl to 2bbl adapter should help keep the intake charge moving fast.
 
[url=https://classicgoldwings.com/forum/viewtopic.php?p=185485#p185485:qroivq71 said:
Hyde » Sat Dec 31, 2016 10:54 am[/url]":qroivq71]
Thanks for the replies guys, currently reading through your thread canukxxxx. My riding condition can be from 20F too over 100F depending on the time of year so icing could be a real concern. Glad I found this site though its been very helpful so far. I have noticed that most on here use the VW intake with homemade runners of some sort, has anyone used the sort of intake I am with an adapter? I think the 1bbl to 2bbl adapter should help keep the intake charge moving fast.
I was running the 2 to 1 adapter for awhile but had a problem with the engine dying when rolling to a stop. Seemed like the heat I was applying was not enough to keep the bottom of the carb warm. With the carb mounted directly onto the manifold the manifold and bottom of carb would get warm.

An advantage of using the adapter is that you can mount the carb sideways and keep the electric choke.

Brian
 
Well as it stands Ill have to use it with this manifold, if I cant get it to work I may try and source the "correct" VW intake. A little over halfway through your thread, very informative so far!
 
Now that I think about it dying coming to a stop would even be liveable compared to my stock carb rack! Even after synching and trying to hunt down air leaks I always had a hanging idle, I mastered the art of reaching down and pushing down on the linkage while rolling up to a stop to settle the idle if I wanted to go to nuetral. What a pain!
 
[url=https://classicgoldwings.com/forum/viewtopic.php?p=185489#p185489:1mwkerkz said:
canuckxxxx » Sat Dec 31, 2016 3:36 pm[/url]":1mwkerkz]
[url=https://classicgoldwings.com/forum/viewtopic.php?p=185485#p185485:1mwkerkz said:
Hyde » Sat Dec 31, 2016 10:54 am[/url]":1mwkerkz]
Thanks for the replies guys, currently reading through your thread canukxxxx. My riding condition can be from 20F too over 100F depending on the time of year so icing could be a real concern. Glad I found this site though its been very helpful so far. I have noticed that most on here use the VW intake with homemade runners of some sort, has anyone used the sort of intake I am with an adapter? I think the 1bbl to 2bbl adapter should help keep the intake charge moving fast.
I was running the 2 to 1 adapter for awhile but had a problem with the engine dying when rolling to a stop. Seemed like the heat I was applying was not enough to keep the bottom of the carb warm. With the carb mounted directly onto the manifold the manifold and bottom of carb would get warm.

An advantage of using the adapter is that you can mount the carb sideways and keep the electric choke.

Brian

im not sure ...but i think rolling to a stop and die out is gas slushing in the bowl of carb ....seems the leaner i got the idle the less a problem this was ...till now i dont have problem with that unless i really stop fast ...mostly just an opinion here ...also i have my float lower that recommended..

i must also say my bike is not honda stock set up ...its a 1200 motor set up with early 1000 cams 1100 heads and knotched pistons ...it really sucks the air in .....
 
Many varieties of intake builds in use. No reason why yours will not serve just fine as long as it seals up.
 
Cant stress enough how helpful this site has been. I need to get some propane for the shop heater before I can make anymore progress, awful chilly here.
 
[url=https://classicgoldwings.com/forum/viewtopic.php?p=185494#p185494:2pqny825 said:
joedrum » Sat Dec 31, 2016 3:57 pm[/url]":2pqny825]
the other brian has one just like yours ...the manifold there fine if they dont leak air at the stock horns ...

My manifold isn't the same (center tube is round and not square) but I am running a 34 pict 3.

This morning it was 29 degrees out. The electric choke on my carb is disconnected and the mechanical conversion kit I installed isn't doing what I want it to do, so I don't have any choke at all right now. Anyway, I just twist the throttle two or three times to give a few squirts of raw fuel down into the manifold and it fires right off... that is as long as the starter clutch engages correctly.

When I have it running, I just lock the throttle open at about 2,000 rpm for a few minutes and then I am ready to ride. No heat, no choke, AND no icing problems even in 29 degree temps. I know there are those that claim that heat is a must if you want to go the single carb route, but as Vince mentioned, that myth has been busted.

I did NOT solder the hole in the butterfly closed or mess with the tube to direct where the fuel dumps into the carb. What I did do is adjust the jets, and then adjusted the acelleration pump until I have the smoothest take-off possible. I have no stumble that I notice so far.
 
My 74 Kombi with a Subaru EA81 in it doesn't have th choke hooked up and I use the same technique to start it. Luckily we don't get too cold here in Queensland. :yes: :whistling:
 
i have learned thaty the closer you get to getting dial in good ...icing becomes less and less a problem ...my dft has no choke at all not even choke plates on the carb ...i wanted maxium flow for the air and i was dealing with a to rich condition to begin with ...method mention above with throttle lock and squirt of gas is all i need to start the bike ...as brian said ..it more like ..is thstarter clutch going to work to turn the motor over is the no go deal ...choke was not needed ....

i rode down from conneticut to fla ..it was cold and bike run flawless ...no icing issues at all
 
[url=https://classicgoldwings.com/forum/viewtopic.php?p=185501#p185501:3ugspk7u said:
brianinpa » Sat Dec 31, 2016 4:39 pm[/url]":3ugspk7u]
[url=https://classicgoldwings.com/forum/viewtopic.php?p=185494#p185494:3ugspk7u said:
joedrum » Sat Dec 31, 2016 3:57 pm[/url]":3ugspk7u]
the other brian has one just like yours ...the manifold there fine if they dont leak air at the stock horns ...

My manifold isn't the same (center tube is round and not square) but I am running a 34 pict 3.

This morning it was 29 degrees out. The electric choke on my carb is disconnected and the mechanical conversion kit I installed isn't doing what I want it to do, so I don't have any choke at all right now. Anyway, I just twist the throttle two or three times to give a few squirts of raw fuel down into the manifold and it fires right off... that is as long as the starter clutch engages correctly.

When I have it running, I just lock the throttle open at about 2,000 rpm for a few minutes and then I am ready to ride. No heat, no choke, AND no icing problems even in 29 degree temps. I know there are those that claim that heat is a must if you want to go the single carb route, but as Vince mentioned, that myth has been busted.

I did NOT solder the hole in the butterfly closed or mess with the tube to direct where the fuel dumps into the carb. What I did do is adjust the jets, and then adjusted the acelleration pump until I have the smoothest take-off possible. I have no stumble that I notice so far.
That's interesting Brian because it sounds like you didn't modify the carb but did some careful tuning to get it to work right without heat. Before I read this post I would have said that to make the stock carb to work is with heat and I still think that's true with the carb as delivered. But if tuning alone can do it then please give details. Sounds like a game changer.

When I first tried my DFT (without heat) it seemed like a lot of gas was being sprayed in by the accel pump...did you reduce that somehow? Did you go up or down with jets?

Brian
 
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