strange clunk

1981 430XC. Bike runs good & starts easy. When you kill it in gear or out of gear it has a resounding one time clunk, like a rod knock? It's loud and abrupt. It happens almost every time. This can't be good, please advise.

If you want to check the rod without pulling the top end, this is how to do it.

If you have a plunger indicator you are off to a great start. Or if you do not have an indicator you can use a straw,pencil, or any thing else rod shaped to show any motion. You need the drop indicator in the spark plug hole to show if the piston is moving when you twist the flywheel CW and CCW. If you can rotate the flywheel both directions any amount whatsoever with no piston movement, that would indicate a bad or blown big end bearing. If there is no radial play then the issue will be under the clutch cover at best or within the centercases at the worst.

I came across this method when I was working on my 1982 Montesa 349 Cota. When I got it as a basket case I had to remove the ignition flywheel. I found considerable radial play in the mounted flywheel so when I removed the head it was confirmed. I saw the same pocked combustion dome that I saw in 2 of my Husqvarnas that came to me with blown rod bearings.

Drain the oil and inspect for chunks. If none then it pretty much has to be in the parts lubricated by pre mix.

Possibly a badly timed pawl on the kicker? Maybe?

kicker pawl is my guess, I put the 400 back together 1 spline too far and that's exactly what happens. hurry up and get it out as the pawl is being eaten alive in there

I love you guys. Followed the suggestions and I'm certain it's the pawl. All kinds of shavings in here. Searching posts now for the proper procedure of the splines. Thank you!

check the roller bearings in the kicker shaft and also in the idler gear (behind the clutch) as well..they can break up and also make weird noises as well as serious damage. I would replace them if you can while its all apart for piece of mind ( I have some in the drawer for the next "sidecover off")

first pic shows the brass bushing instead of a roller bearing. Second picture is what I believe to be the correct pre-load on the spring but the pawl had late engagement and it did not allow for a full top to bottom kick. Im going to pull the cover again and possibly grind away the plate for quicker engagement.
Also need to verify that the washers are behind the plate and that the spring isn't all clapped out as huskydogg referenced in this helpful video

https://www.youtube.com/watch?feature=player_detailpage&v=_Va1ZUZF6jk

Rule (1) never take your kickstarter off unless you have to.

no...husqcommandment 1...thou shalt only take the kicker off once.....

Hey, we all learned the hard way before this place started. I know I am glad this forum is here

i think every person here has wondered "what the heck"....taking that kicker off and the feeling that shaft unwind!

ohhhyeeaaahh and the sweat and swearing and pinched fingers ....did I mention the swearing??

I suppose the stop on the outside of the case should give us an idea what is going to happen.

Got a new clutch cover, pawl & spring and scored a kicker on eBay. Used 5200 to adhere a piece of conveyor belt for the stop. Everything seems ok on the test fit and the kicker looks properly indexed. Fingers crossed. I probably won't paint the new cover? thanks for your help cafe dudes.

I didn't paint mine and its survived fine

I got the new HVA aluminum cover, pawl & spring installed and the kicker indexed correctly. No binding and it felt good with turning it over by hand. Started it, took it for a short loop and was excited to take it for a good ride the next day. Went out in the morning to hear it run before I loaded it up to go riding and when I kicked it over the kicker went limp and so did my hope. I now have a rebuilt motor with a cracked left case. Let's just say I'm learning everything the hard way on this bike and being a noob is draining my wallet and my confidence. My theory is that the PO indexed the kicker incorrectly when he received the rebuilt motor back from Britt Davis. I didn't figure it out until it was too late with the gear slamming. I think the HVA clutch cover exposed the weakness in the case, I don't think it caused it. A couple of my buddies think it was an uneven surface of the new cover that caused the stress. Either way it sucks. Anybody have a pair of 430 cases? Any suggestions on repairing the case? Any advice on which explosives I should strap to it prior to rolling it off a cliff?

Damn that sucks. Wish I had suggestions how to correct the problem but I'm not that familiar with the 80's stuff other than riding them. I'm sure others will be offering up suggestions soon.

left you a message on instagram bud..