Technical Hello needed with a chevy 235 engine

Hello
I have a 235 engine in my car .
If I Start the engine it runs if i eccelerate it wants to cut off .
I have a New coburator Kit on a New pertronix in the Distributor .
If it Idlles high it runs but Black smoke .
Wath can it be .
I board this engine i never had it Running bevore

 

If it is smoking at idle it is running fat, flooding, too much gas. Maybe check your float level first thing or make sure that you have not got a piece of dirt in your needle valve.

If I say something that confuses you ever just say it to me and I'll try something different to say it. OK?

 

I'm with beano on this one. Look down the carb with it running. If you see gas coming out the float is too high or the needle and seat is stuck. Next pull the distributor cap and make sure the advance mechanism isn't stuck. If that's fine, check your timing.
In tech school my ignition systems teacher told me check your basics, check you basics check your basics!

 

What Carburetor are you running? Is it a Rochester? Carter?

Please let me know if my question isn't clear. I work at Langdon's Stovebolt, and we specialize in these engines, so I am sure I can help you!

 

Doni, great website. It's pretty unusual to see a parts supplier with a tech tips section. I wish more company's would do that.

 

If the carburetor is a Rochester 'B' that is probably your problem, even if you re-built it - they are prone to problems.
Check the obvious; float level, needle and seat. Problem might be warped air horn casting which does not allow the vacuum to 'pull-off' the power valve so power valve is 'on' all the time. The power valve is 'pulled-off' by manifold vacuum which is supplied to the carb by a slot in the base gasket which aligns with a hole in the bottom of the carb base.

 

Here is the gasket slot and carb base. Your re-build kit may have had different base gaskets to match different carbs. The hole in the base was re-located (I don't remember what years) - make sure the slot and the hole lines up.

 

Its a rochester rp

 

99% of our customers end up updating their carbs due to them being prone to so many issue. Not to mention what today's gasoline does to any rubber parts... (at least in the USA). Have you considered updating?

 

So really, really love this! We have several clients who have simple issues like this and don't realize it. Combine this with the different variations of jets and venturis... it's simply a disaster. Thanks for sharing the visual! (And yes, that hole is important!)