starting problems -revs and cuts out

[davj]

hi
i'm trying to fix my t25 2ltr Aircooled, bought non running, when trying to start engine revs hard and then cuts out will not idle at all. AA guy told me carb was knackered, spent £300 on new single carb weber kit, exactly the same problem as before- not happy. as you've guessed i'm new to t25's, just found this forum any advice welcome,thanx dave

[kevtherev]

Ah
does the weber [spit] have an idle cut off valve ?

did you buy this weber [spit] from Just Kampers?

welcome to the forum... all be it a bit late eh?

[davj]

hi kev,bought weber from vw heritage, webers don't seem very popular reading the forum' as for cut off valve i don't know,this is new to me i'd better get a manuel soon. fitting instructions with kit not that clear. there was the same weber on the van i just swapped them over,it is a bit late £300 late

[kevtherev]

So this is a single carb weber on a 2.0L air cooled?
did you get a name or number to recognise the carb?

[kevtherev]

if you have a cut off valve it will look something like this..(this pic is just an example, )



see the red wire attached to the electronic valve?

[davj]

34/36 progressive carb kit -weber dfev. the only electrical connection i can see is for the electric choke

[kevtherev]

...and this electric choke checks out ok?

[davj]

because engine does't doesn't idle it's difficult to check or adjust, when it starts it just screams into life then dies, i'm wondering if air leak on manifold could cause this, or is it much more serious, because symptoms the same with old and new carb,is problem with carb adjustment or elswhere,does new carb need adjustment? i can hear fuel pump ticking sending fuel so i don't think thats a problem, by the way thanx for your replies any help much appreciated

[kevtherev]

because engine does't doesn't idle it's difficult to check or adjust, when it starts it just screams into life then dies, i'm wondering if air leak on manifold could cause this, or is it much more serious, because symptoms the same with old and new carb,is problem with carb adjustment or elswhere,does new carb need adjustment? i can hear fuel pump ticking sending fuel so i don't think thats a problem, by the way thanx for your replies any help much appreciated

I think that's why folks slate the weber replacement, you really need a rolling road/gas anyliser to set them up on t25's as they don't work straight from the box I'm told.

High revs from start up is a symptom of an air leak for sure, together with backfiring on the overrun
pull that fuel delivery pipe from the carb and point it it into a container , just to make sure it IS delivering fuel

[davj]

couldn,t reply we had 8inches of snow and lost internet conn , took apart -sealed manifold gaskets with a little instant gasket (don't know if this is recommened) checked fuel supply replaced the old carb started 1st time, ahhhhhh!.happy days. quite a bit of oil dripping from o/s rocker cover is this normal. what mpg i can i expect from one of these. thanx for all advice and help much appreiciated

[big red bus]

18 -20 mpg

[jason k]

get it to the rollers sharpish

that carb is realy not very good for the cu as the choke sizes are too small.

its strangling the motor.

jetting will help as its way off from the box

if its lean u could be killing the motor

lean = hot

hot = dead Aircooled