740 carb review also known as DFT DFTA weber

[sgq700]

Atta Boy Joe !!! :clapping:

 

[Dusterdude]

Good info joe

 

[joedrum]

ok ive got a 32-32 dft carb and after the work on jyd it is in line to be modded ...rather cold here ..this will be inside work and situation fits this thread i will take pics and post along the way ... :thanks:

 

[joedrum]

ok ...got some pics now ...this is a very old carb ... needs cleaning but has actually been on hooch and did quite well ...except it was before i figured out how to mod the carb to the oldwing motor ...

this pic shows where i block the vacuum ports...put a plug in the idle circuit shut off solenoid hole. the plug is wrap with black tape like teflon tape as the threads dont really match .... and a pic of the epa mix screw hole that still had the block in it ...i just hack it off with hack saw..epa been screwing up carbs for a long time ...the vacuum fitting come out rather easy ..piece of vac hose pliers and some smart hand to grip just right and twist back and forth and they come out and can be reused ...to the left and above springs in the idle speed control screw that actually moves the carb throttle linkage...

cant remember much on how i defeated the power valve ...but i can tell now ...the screws are meaningless ...i tried to take it off so i could look and see ....seems to be welded together now ..and no look see at all ... must be cram full of epoxy and then screw together ...hmmmm id say with no guts in it ...seems to have worked really good :hihihi: above that you can see where i block the epa venting system from hell and solenoid ....on the jyd i just pulled the solenoid off and the brass hose fitting and left the holes open ...the device on the right above linkage is the accelerator punp it is left intact

 

[joedrum]

this basically shows the weber progressive linkage and some carb info ... i actually use the stock weber linkage highly beaten into to what i want ..for throttle cable look up ... may do that later and show it

this shows the primary throttle plate mod ...it is basically 9/64" hole ..on the 32-34 dfta car hooch has i slowly worked up to this hole ...it seems to have really good on the 32-32 carb also as that is what jyd has and runs well ...the idle circuits are about the same if not exactly the same ..the the cutouts out in the barrels that lead to circle and a hole are vacuum ports one for sure is auto choke and the other is power valve ..they are blocked in other places ....

this is not a 32-32 carb top....it is a 32-34 top ive never used this yet as the fuel hook up wasnt in a conveinent spot and i use the 32-32 top on hooch instead ...but there close to the same ..need to rig up a fuel feed for this one ....the hole on the far left is where i blocked jyd fuel vapor venting system on that 32-32 carb ...just below that is an open slot that leads into the bwl area in the carb and is open in the right end of it ...it is above the gasket that looks like it blocks it off from the bowl area but the bowl vants around the float seat opening and also right in front of the float towers there is and open place also ...

this shows the opening in the bowl venting tube ...just to the left is where the float seat thread in ....

ok this is the top along the edge ..just above the gas vapor venting from hell is 2 brass pluge ...one of the in the bowl vent ... a plillip screwdriver and a nice little punch makes a super strait through bowl vent .. you can see the table through the hole in the pic ... believe me this vent the bowl good and that is job number one in a full out assault on the throttle secondary and all :whip:

as far as mods go this is about it ... ididnt really cover the dismantle of the electric choke and linkage and choke plates as i cant recall that well ,,,but thers is total take out of that system and vacuum bloctk also ...also for altitude compensation holes in top also ... but with thes mods done you should be able to dial in your dft without hitting snags where carb and motor dont match up good ...jetting simply dosnt work when there is mismatch going on ...in my opinion this these things done here makes clear path for jetting :thanks:

 

[joedrum]

needed a gasket so i am making one out of cereal box...pic not great ...need to make hole for float seat is all that left on the inside part ...

 

[dan filipi]

Looks good Joe.
Screw holes too.

 

[joedrum]

a better pic with float seat put in ...from here i will coat the gasket in something to toughen it up ..so it reusable

you can see the slot with open air just in front of the float tower ...this is where the bowls on either side of carb vent from ....just to right of float seat round closed plug i need to make into fuel feed ...so this top witch is for 32-34 carb on hooch will work in the frame space....right now hooch has the top from a 32-32 carb that has a feed in this spot ....ive been needing to mod this top for a long time :thanks:

 

[joedrum]

today it is rather cold ... i will try and put in a fuel feed on the carb top in the picture above ...in the round plug sticking through the gasket on the right top

 

[Omega Man]

Is this paper gasket meant to be a permanent solution or only for testing? And I'm just asking, but will those uneven holes affect the air flow?

 

[joedrum]

no it will be permanent gasket randy it is as good a gasket or actually be much better that the gaskets that come with rebuild kits when i am done with it ... the uneven air flow you see ...is just like the weber castings they made ...only the outside adges have not been cut right...and probably wont be cut like the rebuild gaskets ...and will hang over some as this adds strength and the paper gasket...the custom gasket will be soaked to absorb a toughener to make it many times better than it is ... i have also made others from the perfect gasket custom cut i made ....so now i have a supply of gaskets ..and they also covers up some holes that are not needed on the oldwing set up as i have my carbs modded to ... :thanks:

 

[joedrum]

gas feed is in now ...used a press in vac fitting the same size as gas line as it is something i had...i seemed to have drilled a nice hole that require some rather good hammering to to get in ....if it dosnt work i have options i can do that will cost bit of money for the right fitting .....i am going to cut off electric choke mount as its not needed and in the way some in access to adjusting screws .. :thanks:

 

[joedrum]

this pic shows the electric choke mount gone that i cut off ...that stuck down several inches below the carb top and is just in the way ...it hung down just to the left of the weber carb choke fast idle screw.....this weber linkage piece will be modded to work on bike ...seems most have very elaborate linkage hook up deals....i mod the weber piece to have very long pull in the throttle grip ...also i modify the progressive linhage to come in much earlier on the secondary ..this shorten the long twist to an acceptable twist and still leaves nice long pull in primary to make it much safer and nice in general riding.... smooths out the quick response to where i like ....but then have it when i want to get into it ...and with secondary coming way quicker it makes for a very mean performance carb over the stock weber set up for a car

this pic shows how slender the carb is now with all the stuff off of it and it is now a joedrum strait carb deal...you can see all the adjusting screws are rather easy to get to now ...big plus when dialing as in setting the screws to go with strait carb only ....when a strait carb is dialed in good it is more responsive than any other set up ...even EFI cant beat the response time ...i know most dont believe this ...but in my opinion there is only one thing that can beat this kind of set up and is a super charger added to a strait carb ....

this pic shows the difference between this top witch is 32-34 carb over the 32-32 carb ...if you look closely you will see screens that open up to the air filter ...along with the bowl venting .....the 32-32 seems to be bowl vent only ...i have never had this on so when this goes on hooch it will new territory ...i am curios what this is going to do i am hoping its a boost..... from the info i read it is and is the preferd race set up top ...that be nice i am always looking for more :thanks:

 

[joedrum]

ok this top is ready to try on the hooch bike ....

i kind of get the impression most think the mod ive done are like to hard to do or feel it the carb dosnt need to go here to work on the oldwing motor or that removing electric choke and even the choke plates will make very hard to deal with on a cold start up ....or that putting a hole in throttle plate is just not needed and if this stuff was done to a carb and it didnt work ...it would be worthless for resale ....

all i can say here the whole adventure on single carb is a gamble from the get go ...there is also plenty of naysayers ...and there is plenty of people who think its all about the manifold not the carb .....well putting a carb on a oldwing that is jetted for the ford fiesta anemic 1.6 liter motor on a high reving oldwing motor and think its right seems crazy to me .... when i do something and put on the table all i have or can with ability ...i am in it to win not just be close .... i got rid of the stock rack cause i thought it was sub par and totally not good enough for me on the best day it could have the ability to be ever ...so i wasnt going to settle for less in the replacing stock system ...i was out to best it big time ...cause i felt the motor just to good to be hampered by an anemic and lacking cv carb system...

to my great surprise over all expectations in the end ..the weber prove to really be the deal for me .....and unlike a lot of people who hoard there success and never give it out or others who feel they own the success and can only be given at a price but still think they own the info ...

i decided i would try and give everything i accomplished to all ...who can make something out of my sub par typing ... as i want all that want to go here everything i got to offer them .....it dosnt mean anything more than ...this is the joedrum way of doing it from A to Z ..i may add to this thread as i didnt really go over much on defeating power valve as it was done already as was electric choke removal and choke plate removal

:thanks:

 

[slabghost]

Well said! Regardless if others choose to go this extreme in modding or simply add heat and call it good. Each bike and each build is up to the owner and his wants and needs.

 

[joedrum]

ok got the hooch carb tower off

pic of 32-34 dft carb ....with the top put on ..other top is what was on there ...a 32-32 top

this pic shows the modded weber stock throttle linkage i cut the E choke arm off and beat the rest of in into a flat submission ...then flip it over so ball end faces out ...cant see the linkage mod but it is done so secondary comes in sooner ....

this is ready to mount back on hooch ...it will be interesting to see if the top makes some difference ... :thanks:

 

[slabghost]

Looks good from here!

 

[joedrum]

I got the new top and all back on hooch ... To review I have never used this top before. It has aggressive inside the airbox venting over the 32-32 top i have been using ...

I learned something today that was huge to me ... If you want to dial in the idle circuit on my modded carb ... do it on a cold day when icing is more likely ...like it is here today ....if you can get the idle and off idle working good on a day of the worst conditions you have got it dialed in ...I spent a good bit of time dealing with it and slowly going from a too rich deal to dialed in just right with good off idle response ....

I just came back in from a second run ... my thought was that after the first run ..the bike will cool down again ...I gave it an hr I'd say ...it should start up and with a bit of throttle lock on it at about 1500 rpm for a minute or 2 it should go on its own ....to my surprise it did this very well ....seems to me the richer the charge the worse the icing is ....on a weber idle and just off idle is all handled by the idle gas jet and also what the accelerator pump contributes to maybe in off idle twists....

with the fixed air in idle circuit as in idle gas jet ..it is in the secondary barrel hole above choke plates if you had them in and also on mine in the hole i put in the throttle plate pretty much sets idle speed at 1000-1100 rpm ... with throttle plate completely closed .....so I don't use the idle speed control screw on the linkage in this dial in like weber does ....but do use the mix screw ..like an adjustable jet to get the perfect charge setting ....

I am very pleased how it went today on the hooch bike idle dial in :thanks:

 

[Ansimp]

:good: :clapping: :moped: :yes:

 

[joedrum]

a video on a very cloudy day about 47 degrees out ... this run is somewhat deceiving ..the throttle has very long pull and this is all primary barrel testing and no where near secondary kicking in ....more like idle... off idle and midway throttle plate opening on primary....this is with the new top on hooch ...my tach also drags behind it seems also .. but it gives good indication of how well it is doing down low in carb circuits....get up hooch :whip:
[video]https://www.youtube.com/watch?v=Kw_atsClGqM&list=UU4n-jRpq9fmvvCw15KDERGg[/video]