11 replies to this topic

[Sam_Gpz600r]

Hi all,

 

Just rebuilt my HIF44 carb with service kit, and car runs better than before... But...

 

I Drove to work and back today and used around 1/3 of a tank of fuel where i would normnally use just over 1/8!!!

 

I set the float to 1mm as the rebuild kit stated,  changed all the seals etc. and set the jet exactly the same height as before. Can anyone help with suggestions as why i have used so much fuel yet the car dosent seem to be overfueling. (if it was overfueling this much it would run like a bag of spanners right?)

 

Any suggestions appreciated, even silly ones ;)

 

Cheers

Sam

[alex-95]

leak anywhere? faulty fuel guage?

[ACDodd]

You need to set the idle mix with a gas analyser.

Ac

[carbon]

Any sign of fuel coming out of the overflow pipe?

[Sam_Gpz600r]

Not a leak that i can dignose with carb cleaner squirts..

 

And the carb has always been a bit off hence the rebuild but it does like to deisel on switch off if im not careful which also causes it to overflow but i haven't noticed it whilst running or since trhe rebuild. The carb used to have a plastic breather cap on the overflow but i swapped it for a hose instead as the breather is directly above the exhaust.

 

I am planning on a rolling road soon but untill then I need to get it running okay as its my daily. My brother has a gas analyser but unfortunately he is about 90 miles away at the moment.

Edited by Sam_Gpz600r, 26 January 2015 - 08:02 PM.

[KernowCooper]

Then if your experienced use the lifting pin, engine revs up stays there = to rich- engines stalls or dies away = to weak

engine revs slightly and resettles = ok

 

Remember though if the engines breather is connected it can make the engine appear rich when its not

[Sam_Gpz600r]

When I slowly lift the pin the engine revs stay the same untill the last bit then the engine revs drop.

Today the car seems to be developing a misfire im not sure if its related but i pulled the plugs to have a look.

and the look like this..

 

 DSC_0693.jpg   62.47K   16 downloads

 

 DSC_0694.JPG   40.11K   2 downloads

 

so looks like the car is a little rich exept for cylinder 4? although im confused how 3 cylinders can be rich and the misfire on the leasn one? anny suggestions?

 

ps should I start a new thread about the misfire?

[carbon]

Little rich? That's a bit of an understatement for plugs 1 & 2.

 

With that much soot on the centre electrode I would not be surprised if you had severe misfiring.

 

Not sure why plug 4 is looking relatively lean, but the heavy fuel consumption looks like choke is being left on... You probably have at least a couple of different issues here - at least one with the carb set-up and possibly also an air leak.

[Sam_Gpz600r]

So after a bit of playing i think I have an air leak on the inlet manifold for cylinder 3 and 4. I am woried this will cause cylinder 4 to be too lean and so cause more damage if I lean out the mixture for 1 and 2?

 

I have another inlet manifold to try but will I need a new manifold gasket?

 

cheers for the help.

Sam

[Dusky]

You probably need a new gasket. Also check of the plugs are the correct heat grade for your engine

[carbon]

I would suggest the soot on the plugs is because of a very rich mixture, not down to grade of plug used...

 

Are you sure the choke mechanism on the HIF is working as it should? Check there is not a sticky cable or other related choke issue.

[Ethel]

The soot on the plugs isn't OTT if it's only been idling or on short, cold, runs while you've been investigating. It could be the seal on the choke spindle has perished, does it need full choke to start from cold?