backfire in carbs????

[BigDaddyDano]

76 bay was fuel inj. now has dual solex carbs it has been sitting for about a year i ran premium fuel 2 tanks now with fuel injector and carb cleaner in tanks i sprayed both carbs with 1 can each of carb cleaner . i have put new plugs wires K& N AIR FILTERS fuel filter and cap on it no points yet had to order them not in yet but they are gapped at .42 and look good book says anywhere between .40 and .50 ? not sure where the timing mark is on the front? it has the degree gauge and indicator but i don't see any marks on the wheel itself. this is my first vw and i can't seem to make the search work right yet any ideas timing ?? thanx in advance i love this forum lots of info

[fusername]

there is a tiny notch on the pully, right by the belt, kinda hard to see, I always paint em white. thats your timing notch.

backfire thru carb usualy means lean. also did you oil your air filters?

[BigDaddyDano]

yes they came pre oiled pretty cool they used to never come that way. LEAN??? ok it smells rich out the exhaust? is there some kinda cheat sheet for elevation what size jets and where to set timing?we are at 7000 ft i run big trucks so if it don't have a computer and burn diesel i'm lost . gonna be a fun project though have to get a carb sync tool and try to get the timing set .

[david58]

76 bay was fuel inj. now has dual solex carbs it has been sitting for about a year i ran premium fuel 2 tanks now with fuel injector and carb cleaner in tanks i sprayed both carbs with 1 can each of carb cleaner . i have put new plugs wires K& N AIR FILTERS fuel filter and cap on it no points yet had to order them not in yet but they are gapped at .42 and look good book says anywhere between .40 and .50 ? not sure where the timing mark is on the front? it has the degree gauge and indicator but i don't see any marks on the wheel itself. this is my first vw and i can't seem to make the search work right yet any ideas timing ?? thanx in advance i love this forum lots of info

That is the dwell the point gap is .016. If any of the intake valves are too tight it will backfire thru the carbs also.

[BigDaddyDano]

THAT MIGHT MAKE A HUGE DIFFERENCE UHHHH... i was going thru the PO paperwork and best i can tell it has 120 main jets and 52 idle's they started at 140's then 135,132,125 ending at 120's tryin to get it to meet utah emissions and the idle jets went from 65 , 55 , 52's wondering what would happen if i go back up to 140's with 65 idle's . this thing is a real dog absolutely refuses to pull any kind of hill at all runs out good up to 65 -70 on flat or down grade but as soon as it hits any incline it's back down to 45 or less depending on the hill . there must be some kind of formula to figure how much fuel to air you need at 7000 ft elevation? OR DO YOU JUST GUESS with carb sync tool and timing till you get a good combo that works that keeps your CHT IN RANGE and has pretty good power

[fusername]

pretty much right. 65 70 is all that bay will do on the highway, so expect that. I thought that was your dwell. do you have a dwell meter? it is more accurate and easier to use than setting the points with the gap. I just ball park it with the gap to get it running ,then work backwards from there.
What is the timing set at? and what dizzy do you have? If it is the proper dizzy, my timing setup is this:
pull off the vacuum line, get the thing idling, check the timing, it should be 7.5 btdc, 850 rpm. now rev it untill it stops advancing, which I think is around 3600 rpm, just keep going till the line stops moving. this should be between 28-32, dial it in untill it feel right up there, don't tlet the timing go past 32 though. Timing can be adjusted for altitude, but I don't know what direction or at what altitude. with the vacuum line hoooked up the timing will go past 45 or something crazy, cause it only advances the vac when you are under partload, the extra advance helps emmisions and gas mileage, and since it's only during part throttle it doesn't bake the engine.
as for mixture, you have me beat. this is a good question for the typ4urm. Its a forum more about our big ole type 4 engines, thats what kind of engine you have, vs a type 1 or bug engine. It's not a forum about type 4 the car model.

oh and welcome to STF!

[BigDaddyDano]

hey thanx. i'll get a meter tomorrow and give it a shot its all stock except the carbs it was F.I. but PO changed to dual carbs i don't mind the speed but it should pull better than it is . i found a guy in rock springs that works on VW's so i'm gonna pick his brain tomorrow as well.Maybe i'll just swap drivetrains and put one of those monster 2387's in. hehehehe

[fusername]

thats 45mph in third top speed? deffinatly a tired engine or just out of tune. if your gap really is .050 that would mess with it. Get her dialed up and see what you think. since this is your first VW I am gonna mention a few obvious things, not cause I think your dumb but I just have no idea who you are and like to cover the bases.

this thing is aircooled, it depends on RPMs to spin the fan to cool it. you want to keep the rpms up when you are pushing it hard
if you just climbed abig hill, you worked up a lot of heat, let the engine sweat it off by comeing down the otherside still in gear so the fan can spin, throwing it in neutral just lets it get hotter and hotter
type 4 engines, especially pushing a big ole loaf of bread, like to spin high, shift at 4k, it sounds a bit louder and meaner than a water or modern engine, but its what she likes. when I am merging with traffic I don't shift till 4.5 or higher in a pinch
don't go up a hill under 2400 rpm, you'll melt those heads, and 4th gear is not for city driving, you won't get enough cooling air

uhhh, live fast, enjoy the slow lane? my brain is too taosted to come up with a good ole list of tips right now, so I'll stop while I am ahead.

oh did you adjust the valves, and are you running rottellla T oil? cause you should. oil is a mucho debated topic for these old engines, and 90% of oil is not good enough for them. two reasons, they run hot oil temps, and they have flat tappet cams.

[BigDaddyDano]

hey thanx yea i'm gonna get it setup right and yea thats about right 45 in 3rd gonna get a tach and a dwell meter and order a CHT GAUGE !!!

[fusername]

make sure you get a Dakota digital gage, thee VDO one is useless.

[BigDaddyDano]

yea thats the one i'm lookin at.

[wildthings]

0.42 is the point gab in millimeters, that works out to .016 in the English system. Set new points at .018-.020. The .016 spec assumes there has been a little pitting.

[BigDaddyDano]

i have also heard that you can set carbs up with a vacuum gauge on each carb then adjust for max vacuum at idle anyone ever hear of this ??

[fusername]

that is how you sync the carbs if you don't have a uni-syn or a snail style guage. basicly you adjust the throttle stop plate untill both carbs pull the same vac, which means they are pulling the same air. hopefully. a nice system if you have a board w/ 4 guages to sync 4 carbs on the fly much faster. for us mere mortals, I prefer the snail.

also, I am not sure it works with your solexs. I don't know those carbs from a hole in the wall.