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weber carb guys DCOE/DCOM jets and misc. Q's?


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 I have dual DCOM 40's  , pretty much DCOEs with upgraded pump system..



Right now I have 138 mains with an F64 emulsion tube, 160 air corrector and 160 holder, 35 pump jets and 32mm venturi/choke im going to be ordering 50/ F8 's idle's i believe .


so my question is:  I cant find any info on the F64 tube now from what i have read,  i  think it would be really rich  and and only really for high speed WOT??

has anybody heard of these numbers on the E-tube? and what are your ideas about the numbers


also the choke was eliminated and it appears that im missing starter jets( which i shouldnt need unless i have a choke correct?) 


am i right or wrong .. should i look into the more common E-tubes?


im just trying to get the right jets to get them started and running then fine tune after



 Weaker                              Normal                         Rich

F3 , F1 , F7 , F5 ,F2-F4 ,F13 ,F8-F11-F14,F9 , F12 , F6


and do you think the above numbers are adequate to get initial start up?  


now before anyone post links to the threads about jetting-tuning dont bother ive read them.  :geek: 














missing starte jets?




choke/ cold start canceled 




the main diffarence between DCOE/DCOM






and unknown screw/ valve deep in there


the other carb has caps over that area it seems 




and test fitting for my DIY backing plate and air horn sizes



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Stock jetting for DCOE is a sticky here !  Just get it to whatever is baseline spec for your motor.


tip;There is a shop in hayward called the buggy house, they carry weber jets if you need em locally.  Lots of VW shops should carry em if you don't want to order online.


 What head are you running? Does it have water ports for the manifold? You may need to block these off/ freeze plug them to run the side draft mani. 

I have that line plugged on the water inlet on my motor and have no issues.


Slight port deviation should not be a big problem, it won't be ideal but it should run fine.

Somone correct me if I'm wrong...

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well i was told by  the PO that troy ermish rebuilt it, so i checked too see how big the cam is and it has a .280/.480  10* LC  so abit bigger than stock i believe but not by alot,


that shouldn't cause any issues with the balance tubes on the intake mani?


and is it still a good idea to run the crankcase breather to the intake? if it will still be ok to run it im going to tie it in with my brake booster

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okay so i think i know why it was putting out bluish smoke  i had nowhere to put the crank case breather so i let it hang i noticed that it was dripping oil/vapor while running 


then i made a T connector for my crank case breather and brake booster hooked it up  im thinking that there is oil still being pulled into the intake from the hose from when it was hanging and dripping, there is no one way valve inline or any thing so could this be why im getting bluish smoke ?


also the motor has less than 40-50k from complete rebuild and the hardest ive driven it was to canby last year so i dont think its anything major  :confused:


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Mine idles at 12.2 AFR ... thats correct for a cammed carb motor from what I've read.


Blue smoke = oil.



What does the afr show when it backfires out the carb?  Usually a lean condition.

when i punch it its goes to about 14-15 but when i let off it jumps to about 17-19  


now i have not balanced the carbs yet since i dont have a carb balance tool .  



also im not losing oil infact its at about the H on the dip stick would the oil being to high cause some burning issues? 

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usually covering any carb air intake and motor climbs is a vacuum leak 

sputtering and backfiring is most likely the carbs not being tuned 

they have to flow the same or they fight each other 

each side of each carb feeds one cylinder so if they are not matched it will run shitty and do nasty things like hiss and sputter

also make sure your throttle cable doesn't rub on your brake lines it will take time but it will wear through it and you will have no brakes when you least expect it 

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another thing if i put a hand over one of the carb horns circled in red engine starts to climb


but if i cover one of the horns circled in blue engine dies....balance issue ?



also the one circled in red is the carb that has a pulse hiss 





your hand is acting as a choke.


Red ones too lean


Blue ones slightly rich or just right.  Revvs should dip slightly when choking the carbs. 


synch the air, then tune the mixture.  change the screw until you can head the idle go up/down set it to 'lean best' on each barrel of the carbs.  It will take a while if you're new to sidedrafts but you can at least get it set well enough to drive.


Balance the airflow with a sync tool ... there is no way around it this NEEDS to be done. 

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  • 2 weeks later...

ok guys so road tested her today


so start up and warmed up: after running temp is achieved, it idles kind of rich 11. ish  


accel. almost perfect maybe a little rich 12-14 thru all gears WOT 


de-cell. really lean 19-20 in any gear... aslo after de-cell. to stop idle is really lean 17-19 


cruising/ light throttle   is lean 17-19 


any ideas?

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