Golf Carb Jetting

[M3THANOL]

Hi guys, I just thought it would be good to get a thread going, possibly even making it a sticky in which we can discuss the correct jetting for the standard carbs that VW's come with, we can also include the Goldwagen carbs as I am sure there are many cars out there running these as replacements.

I noticed that in the GW carb that was put on my Mk2, the primary jet is a 95 or 98 and according to the haynes manual it says that it should be a 102 jet. My question is where could I get the correct jet? The thread of the jet's that go into the GW carbs is more coarse than the thread on the jet's that go into the standard Keihin carbs. I have noticed that since I put in the A-cam and since the gymkhana day that my car has not been running well, it is clearly down on power and it stumbles if I try and pull off too quickly. Now I know that is isn't a blockage in the accelerator pump, that is working fine. My theory is that even though the jet has always been slightly too small, with the standard cam it wasn't too much of an issue and most likely provided just enough fuel but now with the A-cam in, the jet is too small. I know that the A-cam in my no stretch of the imagination a even a mild cam but the fact remains that is has a slightly longer duration and higher lift than the original L-cam. I am also wondering if there is some un-metered entering the engine but for the life of me I can't find it and neither could a so-called professional. I have checked the rubber carb base for cracks or tears but it seems to be 100's.

I am lead to believe that is is running on the lean side as it often struggles to idle on start-up. It will take and then die, I then need to play around with the choke, pulling it all the way out which makes sure the car starts my them results in the car over fueling and it starts to miss so I then need to push the choke all the way in in order to try and give it a but more air to match the excessive fuel that is now being pulled into the engine, once it is idling on all 4 cylinders I can then once again steadily pull the choke out until the engine is idling at +-900rpm - 1000rpm . Please note that this is only when cold.

Yes I know that I am going to be swapping to a 2.0 fuel injected setup soon but I think most of you will agree that you want to enjoy the car while driving it. This 1600 used to perform much better and for that fact I want to at least get it running as it used to.

[panic-mechanic]

You put it on adyno, then you look at fuelling under part load and full load. That will tell younif you need to change the jet sizes. If it is a competent dyno tuner he will have jet drills so he can solder closed and drill the right size your current jet. No need to stock 10million different jets. Sadly there are very very very few guys that a) have the tools, b) have the knowledge c) have the actual will to still do that.

[M3THANOL]

pretty sad, I too my car to a tuner that swears by carbs, he told me Fuel injection is rubbish and yet he couldn't set the freaking thing right. I guess I need to contact Viper and find out how much a jet will cost me

[panic-mechanic]

Alternatively you can come visit me. But apparently i'm too far and too expensive.

[M3THANOL]

hahaha, dankie oom , will come visit you when the new motor is in, fuel injection and all!!!