Z 750 Twin Working uneven! I think!

Hello am new here on the forum and has a twin Z 750 LTD

Do not know where to start now, so maybe there is someone out there who has some ideas!

The engine is not working properly! Taking time at cold start to go clean, close to clean .... goes uneven at 3500-4500 revolutions and does not sound really good, I think. Is tricky under load.

Has made clean the entire fuel system, the carburetors and the tank
Replacing all fuel and vacuum hoses (also blocked the second vacum pipe when vacum valve to the crankcase vetelationen was broken)

Changed the plugs

I have the original exhaust system installed, there've been around a few years now, how important is the resistance of the exhaust gases of this engine.

Thank you for existing!

Check for leaks between the head and carb holder and carb holder to carb body.
Jim

Rainman wrote: Check for leaks between the head and carb holder and carb holder to carb body.
Jim

Thanks Jim!
You want me to check the carburetor rubber! (This part of the picture), if it is tight against both the cylinder head and the carburetor? And to look for cracks and damage them?

If old, replace them.
Steve

You should be able to (carefully) pass a lit cigarette or something else that smokes in a place where there is no wind like inside a garage all around the joining parts and see if the cigarette smoke gets blown away or sucked in.

Yes.

Just don't forget to shut the bike down before you finish the cigarette. Smoking will kill you but carbon monoxide will kill you quicker.

LuckyBike´s wrote: goes uneven at 3500-4500 revolutions and does not sound really good!

Some ideas:

1) run cleaner in the fuel system like Seafoam or Gumout or similar.

2) Check the timing advancer. They can cause all kinds of problems.

3) Is coil original? Old coils cause a lot of rough running problems too.

bountyhunter wrote:

LuckyBike´s wrote: goes uneven at 3500-4500 revolutions and does not sound really good!

Some ideas:

1) run cleaner in the fuel system like Seafoam or Gumout or similar.

2) Check the timing advancer. They can cause all kinds of problems.

3) Is coil original? Old coils cause a lot of rough running problems too.

What kind of coil would you recommend bountyhunter for these old twins? I'm thinking mine might be a bit tired after 40 years.

Bowman wrote:

bountyhunter wrote:

LuckyBike´s wrote: goes uneven at 3500-4500 revolutions and does not sound really good!

Some ideas:

1) run cleaner in the fuel system like Seafoam or Gumout or similar.

2) Check the timing advancer. They can cause all kinds of problems.

3) Is coil original? Old coils cause a lot of rough running problems too.

What kind of coil would you recommend bountyhunter for these old twins? I'm thinking mine might be a bit tired after 40 years.

Any good coil with resistance of four to five Ohms will work fine.

I am running this one and it works great.

www.z1enterprises.com/product/EM24-72451

They are out of stock at Z1, but any similar coil should work.


Amazon has them.

www.amazon.com/Emgo-Ignition-Coil-Kawask..._product_top?ie=UTF8

Thanks for the help, you guys are the best !! Now she runs properly again!
Took off and made clean, has not changed the coil, to run a turn as soon as the ice is gone

[img size=1.9 ] iloapp.swedishline.com/data/_gallery/pub...dth=1920&height=1440 [/img]
How!!?? Do I add pictures here?