TOPIC:

78 kz 650 sr. Carbs were gone through and re jetted by the guy in texas a bunch of years ago. First start last summer, purred, put on maybe 150kms no issues. Drained all fuel. 

This season, she is grumpy to start, needs full choke and throttle blips, then starts, backfires through carbs sometimes, idle sucks and wont idle until its hot af and even then, not really. boggy etc. It also has electronic ignition and replaced coils with the relay mod. Brand new yuasa battery too. 

My thoughts are..... carbs got crap in them from the tank etc (i sealed it but had issues with petcock and chenged it out, sealed possibly sealer got into carb jets? ) ignition is out ? Maybe i didnt tighten enough? Any thoughts on best place to start? 

thank you

Did you drain the fuel tank and the float bowls? I know you said "drained all fuel" but there is "all" and there is "all".

yes all. at first it took a bit to fill them back up again, if thats where you are headed 

When was the last time you checked valve clearances?

havent. not sure how. thing is it ran very well when i put it to bed so I cant see them changing over one winter? 

it has an auto tensioner.... is there a way to see if its working? 

It's not gonna be a tensioner issue, if the cam chain was loose it'd be noisy nothing else.
As you've done nothing to it since it was working well just laid it up it'll be something simple. As it runs OK when warm and you drained all the fuel it'll likely not be carb related. 
Have you checked you've not got any critters nesting in the air box or a clogged up air filter? 
With the choke on you need a lot of air to get a combust able fuel/air mixture and any lack of air will affect the whole rev range and generally run like crap. 
 

hmmm interesting. I think the tensioner is making a bit of noise actually.... but was before too. No air box, it has pods, they are clear and free of debris. Its stored indoors always in a heated and dry garage. I was leaning toward debris from my many petcock debacles.... The odd bit of backfiring seems weird too. One thing i didnt mention is that it seems to be getting HOT on cylinder 1, hot ish on the others but really hot on 1, which is why i am going to verify the electronic ignition timing again as well. its all dyna with dyna coils (green) 

If it was a timing issue causing the hot cylinder no 4 cylinder timing would be equally hot.
Tell us everything you have done to it since it last ran well. 

You mentioned that you replaced the coils; are you sure everything is installed correctly? Do you have spark on all 4?

Backfiring through the carb (AFAIK) wouldn't be an issue caused by fuel starvation but could be caused by plugs firing when the intake valve is open.

A four-cylinder engine can run on two cylinders but it will sound like crap, make little power, and exhibit some of the characteristics you described.

If you have an IR thermometer you can get good temperature readings from the individual headers.

I would also suggest you check for air leaks, a weak mixture will make the cylinder run hot

yes I had one but it died and was hard to source another during covid.