i need help locating a faq or some help on modifying a weber idf for blow through use. i currently have a weber on a motor with an old school cartech blowthrough setup on it. problem is i can not get it to idle out of the mains. i have attempted to contact rotary shack without any success. are there possibly any other venders that could help?
thanks!

 

go to rotaryengineering.com for turbo-carb help....

 

thanks!!

 

is it rich or lean ?
what is the idle jet size?

 

according to the wideband its pegged rich. but when i say it wont idle if you get it out of the mains it acts as though it is out of gas, not rich. it just bogs and dies.no black smoke or backfiring
as for the jet size i did not make a note of it as i took the carb apart in a motorhome at the sand dunes. but when the carb comes back out i will check it .


on a seperate note, do either rotary shack or rotary engineering exist any more ?
i have put in calls and emails to both and yet to recieve a response from either.

 

poster above, 680rwhp12a, is rotaryshack, aka robert. probably one of the most knowledgeable with a weber blow through.

 

thanks


now back to the blowthrough guy
since you were in the sand dunes i would have to say you have clogged idle jets, remove them and blow them out with compressed air, and reinstall. i get trouble calls every season from the sandrail guys complaining their cars stop idling. that super fine sand in the dunes finds its way into everything!

 

actually had the issue before the dunes. put the motor together 2 days before the trip. assumed the idle was break in compression. it never got better, so performed a compression test at the dunes and it was fine. i then took the carb off and cleaned it in the motor home and paid careful attention to the jets,as with my old dellortos a grain of sand was always the cause of idle misses and pops.
jets were clear and all passages were blown out with carb cleaner however it made zero difference on performance. the only thing out of the ordinary that i saw was the idle needles had rust on them. i was told the buggy would idle all day with the old engine which had been about 3 years ago in which the carb had been exposed to who knows what.
that is the story up to now.

 

i need to know the idle jet size?
what fuel pump are you running? what is the fuel pressure at idle? what fpr are you using?