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chinkamon

1500 precrossflow Gt carb flat spot

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Get rid of the choke flaps and rip out the choke mechanism  altogether....free

Buy the kit that changes from dgv to dgas.£40

Knife edge the butterflies with a nice file. Free if you got a good file

Makes a difference

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The chokes will be a lot bigger then the 28/36 ones. So, jetting will be very different.

Did you not find the carb spindle opens the opposite way to the 28/36?

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Did a bit of digging re the choke sizes on another forum not knowing the ins and outs of this carb it would appear the 32/36 has the same choke sizes as the 28/36 quote

 

you look a bit deeper you will see that the 32/36 has 26/27mm chokes 

how true this is I don't  know without physically looking at the carb. If this is so then you should be able to use jet sizes suited to the 32/36 as fitted to a 28/36

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I've seen this before, all the comments are spot on and worth checking out/following up.

But don't get the tunnel vision... these set ups are renowned for getting a breakdown on the electrical HT side (Coil, Dizzy Cap, HT Leads & Spark Plugs) when under load only.

If you've got access these spares, I'd try swapping them out one at a time.

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9 hours ago, notenoughtime said:

 

 

Choke sizes will be different hence 28/36 versus 32/36 

 

 A 32/32 has 23/24 chokes, a 32/36 has 26/27. A  A proper 1500gt 28/36 DCD has 26/27 chokes from the factory. That means the 28/36 DCD and the DGV 32/36 have the same size chokes. 

Where they are different is the size in the barrel size at the manifold end - ie 28/36 DCD has a 28mm primary and a 36mm secondary, whereas a 32/32 has 32mm opening on both primary and secondary on the barrel opening, a 32/36 has a 32mm on the primary and a 36mm on the secondary. 

In reference to changing choke sizes made elsewhere in the thread it is not possible to change the chokes in a 32/32 or 32/36 DGV as they are "cast-in". Because of this the DGV has the choke size written on the barrel exterior. Partly because of this I much prefer the DCD to a DGV as it is a much more tunable carburetor and reminds me slightly of an upright DCOE in the way it works when compared with a DGV.  

The only part you can remove/change in the barrel of the 32/32 and 32/36 are the auxiliary venturis. 

In terms of the O/P's issue the DGV and the DCD should have the fuel pump jet squirting fuel down the primary barrel, which is easy to check when looking down the carb (from the top if carb is in your hand as the other way may give your eyes a wash-out with petrol!!) and opening the throttle.

I find a good check is to have the engine running with the air filter off. Then using a good torch check what fuel is being delivered in which barrel at different openings. You will see fuel being sprayed from the fuel pump nozzle but you should also see if both auxiliary venturis (one for each barrel) are delivering fuel of similar quantites. If they are dripping fuel under running that is no good - it should be more of a mist, or even a "curtain" of fuel.

 Beyond that you will need some jets etc and a bit of patience, 

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Wow thanks all for your comments, I'll have a look if I get time today, I've seen fuel squirts in the primary when the accelerator is pushed but haven't seen any go in the secondary if it's pushed hard or gently, which is why I was thinking a blocked jet

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So. 

At the hot rod shop earlier having a play about and our new gas emissions tester turned up today so had a 'tuning  session' turns out she was running approx 3 times richer than needed ?

Adjusted mixture, idle speed and that combined with blowing the carb through and swearing at it seems to of sorted it! 

Quick blap up the road and she's faultless!! Thanks all for your expertise and help it's really appreciated as always ?

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