2000 Response - engine running rough

[Nzresponse2000]

Hi folks, 

Have a 2000 response lx, carb. 
has a 5.7ltr monsoon motor. With Holley carb. 
Approx 450 engine hours. 

was running ok, then has developed a problem: 

- starting off quite Fumey, struggling to idle. 
- have replaced the floats in carb, and seats. 
- have removed spark plugs, found to be very fouled up. Replaced with new. 
- oil level had come up, smells like petrol. Have replaced with new oil. 
- pcv valve hose had a kink in, when removed hose, engine idle revs came up. Appeared to run better. Replaced hose. 
- pcv valve appears to be working ok. 
- distributor appears ok

- compression tested - ok

- remove fuel, replaced with new. 
 

after all that, still no good. 
running rough, very fumey, hard to start. 
 

absolute nightmare! Any ideas?? 

[Woodski]

Things to look at for overly rich carbureted running:  Have you verified the choke operates properly and not staying closed?  Float seal working and floats set correctly?  Jets didn’t come loose or fall out?  What type of fuel pump?  Correct pressure?  Clogged spark arrestor?  Bad coil, incorrect ignition timing.

[Rednucleus]

When was the last time you got a NEW cap, rotor and wires?

[Nzresponse2000]

Choke is definitely operating as it should. 
cap and leads less than 12 months old 

[justgary]

You didn't say you gave the carb a good bath, you just replaced the floats and seats.  I would pull it, disassemble it, and soak it in a can of carb cleaner (the gallon can of good stuff with a basket inside, not the spray cans).  After that, blow it out with compressed air, inspect it, and reassemble with new gaskets.  At least that way you can be fairly confident that you don't have a blocked air passage or a leaky gasket.

The list @Woodski mentioned is a good one, and it has some pretty low-hanging fruit to easily pick.

[formulaben]

On 1/13/2024 at 2:53 AM, Nzresponse2000 said:

Choke is definitely operating as it should. 
cap and leads less than 12 months old 

What about the rotor?

[GaleK]

And ignition control module

[justgary]

7 hours ago, GaleK said:

And ignition control module

I'm not sure the carb version has one, but in general that's a great place to look as well.

[GaleK]

I "think" the icm on the distributor is the same? (Totally could be wrong)

 

I can't get to our carbed boat for a week or so... I CAN confirm the efi does  😎