Choke flap stuck in engine

Hey guys, so I was riding today, had the choke on and all of a sudden my rpms started to rise by itself. Pulled over and noticed a ticking sound coming from the engine. Got it home, took the cam cover off..didn’t find anything strange...and I remembered something about the choke flaps getting sucked into the head. Sure enough, took choke out of cylinder 1 and it was missing...took choke out of the other ones, they were intact, however starting to fail/ get loose.Where do I go from here? Obviously take the head off but is there anything else I should look for? Is the noise a symptom of a flap getting stuck in the head? And what should I do about the missing flaps? Thanks!

If the RPMs went up, I would expect the choke flap was stuck in the carburetor. That would be the best case scenario...just pull it out of the carbs and the motor will not be affected.

Quite often, if the flap goes into the engine, it somehow also just blows out of the exhaust somehow. If you think it's stuck in the engine, I would just remove the spark plug and see if you can see it. Also remove the carbs and exhaust to see if it's stuck in a valve. In any scenario where it was stuck in a valve, I would expect the idle to be slower and the engine might even stall. Cylinder 1 wouldn't really be running if the flap stuck a valve open.

Since you removed the valve cover, make sure to release the cam chain tensioner before reinstalling the cover. (Details are in my signature.)

Most people make a new flap or get one on ebay. The Tk22 site has a few tips on what to check for on the flap shafts etc.
s3.amazonaws.com/gpzweb/TK22mainPage/TK2...chokePlateFlaps.html

Okay I’ll take the exhaust off and see if I can take a look in. I’d also like to add that after this happened, it was hard to start and the idle did drop. Also would like to add that when turning the engine over by hand with spark plugs removed...there is a hard spot where it gets hard to turn over...also symptoms of a flap stuck?

Ant_5445 wrote: Also would like to add that when turning the engine over by hand with spark plugs removed...there is a hard spot where it gets hard to turn over...also symptoms of a flap stuck?

Id say that is the point were your compressing the flap that’s in the cylinder.

A leakdown test will let you know if a valve is stuck open, and you would be able to hear which one is open without removing the exhaust or carbs.

A leakdown test uses a fitting in place of the sparkplug and you connect an air compressor to pump air into the cylinder while it is in a position where both valves should be closed.

So I didn’t see anything when looking into the exhaust ports, however I did do valve clearance Measurements with a feeler gauge... all exhaust valves are .20mm...intake valves on 1 and 4 are .13mm however 2 and 3 are .06 and .08. Would this be the issue instead....?

Update: took the head off and surprise, damage to cylinder 1 combustion chamber and bent valves. Now to locate news valves and sent the head to my local mechanic to have him fix the damage. Great.

Aw, that sucks. Sorry to hear that. I think the valve part number is the same as standard Kz's so there should be some easily available. I'd look at any valve from Kz550 A2 to A3, C2 to C4, and D's. I think the 1980 model, (first year in the U.S.) had different part numbers for the valves than the D model, but may still be swappable. It hasn't been confirmed that I'm aware of.

So while i'm waiting on parts my next question is, should i go farther into it and get brand new pistons, cam chain guids ect? or just clean it up a little bit and throw the head back on? Little bit worried as i have never fully torn apart an engine before or at least getting down to the pistons lol also, can the front chain guide be removed with the cylinder head on? I know the rear guide needs it off to be removed...

I'd pull the cylinder and measure the pistons and bores against the specs in the factory manual. If all measures okay I'd bottle brush hone the bores and install new OEM rings. New gaskets all around of course, and new valve stem seals. OEM gaskets are the best; aftermarket kits range in quality from passable to downright criminally crappy. It's not worth it.

If you have the right measuring tools you can get an "idea" of what condition your cylinders are without pulling the block. If you don't have the right tools perhaps you know someone that does and they can measure things up for you. The one important point to remember is that many times when you take the head off you almost automatically break the seal of the cylinder block to engine block. This happens a lot when guys try to muscle off the head. Food for thought.
Rick H.

So more updating: decided to clean the carbon buildup on the top of pistons and noticed these gouges + what looks to be scratches..might have to hone it..? What do you guys think? 615 kit if it’s that bad?? This is getting worse and worse by the second!