TOPIC:

Will take 'em off yet again - getting pretty good at this now!
Should have some pics of the carb undersides and jets for you tomorrow to help with this "mystery."
(Sorry about the attachments in the previous post - grabbed the wrong pics, duh-oh!)
These were of me on my Mach IV at a street circuit in NZ back in '74.

Here's a pic of the underside of the carbs (I hope - having some issues with Microsoft Picture Manager!)


I'll post a couple more of the pilot jets shortly

Looks like that on worked - a pic of the jets which are marked Mikuni 17.5.

And another close-up of the pilot and main jets installed.

and one of the carb body where the pilot jet screws in.

Hoping that someone can help me with this problem!
Open to any suggestions at all - I just want to get this fella running nicely.


Cheers,
Bill.

Has clear-tube testing been done to determine whether fuel levels are within spec (and in this case not too high)?

Good Fortune!

Clear tube test has been done - all in spec.
Thought it might have been a weak spark which causes rich running due to buildup of
incompletely combusted fuel. Coils, plugs, leads, caps and all wiring to loom is all new with 12volts at coils;
have done static checks on the coils - Rp is 4.1 Ohms and Rs is 23.5K Ohms, with no leakage/breakdown
between primary/secondary windings.(have also got a good earth for the coils.)
Still think it's the pilot system but not sure where to look next.
(Hoping that Steve may have something to offer after looking at the pics below!)
Now that the carbs are off (again!) will give the carbs a good soak in carb cleaner and another blow-out this weekend.

No pics?
Steve

Sorry about that - pics were too big I think.
Try again :

What's with #3 jet? Pics of plugs?
Steve
Steve

Not sure what you mean Steve?

"What's with #3 jet? Pics of plugs?"

1st attachment is of underside of carbs
2nd attachment is of the main jet fitted to the bleed pipe and the adjacent pilot jet (#17.5)
3rd attachment is a (blurry) pic showing where the pilot jet screws into the carb body
4th attachment is of the 4 pilot jets (#17.5)