Some of these things have already been covered, but I'll give you a checklist to check anyway so nothing gets missed...
Sounds like the float level to me, or just fuel supply.
If you accelerate, the motor asks for a lot of fuel (which might not be there)
If you rev it up on your driveway there might be enough fuel in the bowl for it to do that.
So I would be looking at where the fuel comes from. Check these things in this order...
- Start with the fuel pump, check it is putting out decent pressure.
- If that is fine move to the carb, check the float level (do you have a workshop manual?),
- If that is fine take the needle and seat out and check the brass screen/ filter for blockages.
- If all these are fine check your fuel filter and lines.
Important questions:
- Was it all running fine before you changed the carb?
- Why did you change it?
- Do you have any foreign parts (or custom) to make it fit?
That makes the most sense to me, that's where I would be starting
camB wrote:?? So it's surging, then cutting out? Sounds like mixture. When you pump the pedal it dumps raw fuel into the carby (you should be able to see this with the engine off and the butterfly open). If it's dumping this into an already rich mixture it just won't go bang.
Mixture screws only effect the idle circuit in the carb. It has no relevance to any part of the rev range over that. That is what all the other jets do. Have a look at an exploded diagram of a carby. The Solex carbs on my wagon have mutiple jets per curcuit. The primaries have 2, the secondaries have 3. The idle circuit has a screw that adjust the air fuel mixture.
That is how it all works. Here's my carbs in exploded pics.
Note.
primary jets No.s 12 (main jet 1), and 16 (pilot jet 1)
secondary jets 13 (main jet 2), 17 (pilot jet 2), and 19 (enrichment jet)
Hope some of this helps?
Dave...