No grunt..

OK, step son has inherited a ratty but not *too* shabby gpz750. Now, after
charging the battery and a quick squirt of easy start, the thing runs... it
ticks over and revs OK (ish!), but when the engine is actually put under
load, it has absolutely *no* bollocks to it, coughs and splutters and
threatens to stall.. You can actually get it to move, but at no great
pace...and it just wont rev out...

First port of call will be a strip down of the carbs, but any other
sugestions as to where to look?... are there any particular bits on these
that tend to fry themselves or otherwise cause the above problems?

Any prompts gratefully received...

 

Fuel starvation due to shit in the jets or blocked strainer in the tank/fuel
tap. Also check inlet rubbers for leaks.
I'd also check the plug caps/leads, and coils for 'tracking'. Easier in the
dark to see this. The plugs themselves may need replacement too.

JB

 

I'd suspect ripped diaphragms.

Bikes with damaged diaphragms will run, often quite sweetly low down,
but lack all power.

 

Don emerged from their own little world to say

Animal nest in airbox?

 

Same on one of the wet dreams. No diaphragms, just 2 dashpots and the
carbs and jets have been thoroughly submerged in thinners over a few
days to clear the glaze out.

I'm going to swap a carb set off a "good" one to eliminate from my
enquiries ..

P.

 

Incidentally the same symptoms afflict carburetted Saab 900s with split
diaphragms.

It was a nerve racking few weeks.

 

Shit in the carbs.

 

How will that help?

 

I think what he's suggesting is confused by the use of the phrase "fuel
starvation".

If the main jets are blocked it would give exactly those symptoms
described. I agree with what you're saying in respect of fuel supply
from the tank to the carbs themselves

 

Piss in the tank.

 

Prime poetry opportunity wasted there.