X475 Kawasaki Carburator Adjustment

Dillier23 · May 16, 2016

One of my X475's is having a rough time idling and backfires through the carb. I've took it apart, cleaned it well and reinstalled. While I had the fuel in and return lines off I blew them out to clear any obstructions. The valves are also adjusted correctly, new fuel filter, and plugs.

There are two plastic caps on top of what I believe to be the fuel adjustment screws on top of the carb, see the picture for reference.

My question is: Are these two capped screws in fact the adjustment screws? If so, do I need to pop the caps off the get the adjustment correct? They only turn 1/2 way with the black caps.

Billrog · May 16, 2016

Could the timing be off since it's back firing through the carb?

Dillier23 · May 16, 2016

I suppose it's possible, how would I check to see if it's correct?

Billrog · May 16, 2016

I'm sorry to say I know nothing about that engine Diller23 I mentioned timing because of experience with other engines. You could possible google the info. If it has a timing chain maybe it's stretched.

oldnslo · May 16, 2016

Will it run better with the choke slightly on? If yes then it is running lean. If no then possibly not a fuel issue.

Yes I believe the plastic caps do cover the adjustment screws. Not sure if these are for idle mix or main mix though. If your kawasaki is like my 2013 they have two different size idle and main jets for the two cylinders. If you removed these for cleaning i hope you were careful and didn't mix them up during assembly.

Dillier23 · May 31, 2016

Update:
The plastic caps are a limit on the adjustment screws. I used an oscillating tool and trimmed the metal tabs off the carb which allows full adjustment. Mower runs much better with the correct carb adjustments.

blue9249 · Jun 16, 2016

To check timing pull the flywheel cover off , remove spark plug (s) and stick a rod or stick in the spark plug hole. When the magnet on the flywheel hits the coil the piston should be at or close to top dead center. Also check coil air gap, after checking what the spec for that engine is.

I know you said you cleaned it well but these newer carbs ate hard to clean. Work at a deere dealer and we can't warranty carbs without documenting that we cleaned it in a sonic parts cleaner at 135 degrees or higher for more than 30 minutes.

BTW if the timing is off the only thing it could be is a broken flywheel key, will need a flywheel puller to do it.