[B40dash8]

Hello all, My bike has developed a knocking. I have adjusted the valves. All the valves open and close and the clearances were checked. I also don’t have any vacuum leaks in the carb boots. I was told it could be from non balanced carbs and I plan to sync them soon. I doubt that is the problem though. It’s really hard to judge where the knocking is coming from. It seems to be coming from lower case and transferring up to the valve cover. I really can’t figure out if it’s at the valve cover or the lower end. Does anyone have an idea on what could be causing this? I’ll post a YouTube video below. Thank you!

 

[B40dash8]

well it started knocking before I adjusted the valves I was told to check the valves to make sure they weren’t sticking or out of wack. I adjusted them but I set them mistakenly to the inches but used mm. So they chattered when I put it back together. I did them again and now they are quiet. But no there wasn’t a big change in adjustment from when I first checked. Although I didn’t measure it before adjusting. I’m just going by how little they moved while loose in the compression stroke at tdc

 

[B40dash8]

could that happen from oil being to thin? I changed the oil today and it smelt like gas. It was a brownish color No metal shavings or anything in the oil though but it did indeed smell like gasoline

 

[B40dash8]

I just did a compression test on the engine cold and warm.
Left cylinder= 145
Right cylinder=165 Left is lower by 20psi. I would say that’s not good

There is no knocking when just using the starter to move the pistons up and down.

 

[B40dash8]

I will try that when I get home. Thanks

 

[B40dash8]

I tried that and the engine will only stay running on either side of I keep it running with the throttle. The knocking sound is there when removing either side. I synced the carbs today but still have the knocking. The knocking does dissapear above idle speed though. You can hear it in the video. Just as a experiment… I do not have a leak down tester yet but I filled the left side cylinder with 100 psi of air on the compression Stroke at top dead center and the air escapes out of both of the exhaust pipes. In theory shouldn’t the exhaust valve be closed On the compression stroke at top dead center? Here is a video of the sinking and knocking sound that I still have. At this point about a week into it I’m going nuts trying to find out what is causing this knocking.

 

[B40dash8]

I didn’t even think of the crossover!!! Thank you for suggesting that! My next thing to do was to take the exhaust off and just go with that’s coming out of the head. Hmm I will look into the oil pressure switch. I will have to consult the manual for that. Off the top of my head I don’t even know where it is. It’s tough working on these bikes because there’s very limited info on YouTube being it’s such a rare bike. Thank you brother for the crossover info. I never even thought about that!

 

[B40dash8]

Thanks. But I don’t think I’m down for all that lol.

 

[B40dash8]

panic pete. Are any of those adjustable without digging into the engine?

 

[B40dash8]

View attachment 115708

timing chain has spring loaded mechanical tensioner that sticks up under rocker cover.. tap down on it to assure wedges are loose enough to self adjust..
View attachment 115709

That large wedge is supposed to spring down? The larger one doesn’t budge but the smaller one springs down. I noticed that when I was trying to remove the cover

 

[B40dash8]

Okay….So let’s just say I have the cover off and I go to push down on wedge A and it doesn’t move at all but wedge B springs down. Is that a problem. Or does the cam have to be in a certain position and or have to have the cylinder head off ?

 

[B40dash8]

Okay….So let’s just say I have the cover off and I go to push down on wedge A and it doesn’t move at all but wedge B springs down. Is that a problem. Or does the cam have to be in a certain position and or have to have the cylinder head off ?

I’m wondering if mine is jammed also. Hmm

 

[B40dash8]

Tab should move down.. whack down on it with screwdriver handle
I used a small ball peen hammer

I will try that if I can get the cover off. That larger wedge doesn’t move so I can’t spring it down to get the cover off or on. Have no clue how it came off the first time but it took me damn near 3 hours to get it back on. I had to lower the engine. It kept getting stuck on that wedge that doesn’t spring down while trying not to destroy the gasket that no one can get anymore

 

[B40dash8]

I was just reading the manual and

it says knocking could be caused by excessive carbon build up. When I rejetteed the carbs for the exhaust I went for a ride and came home, took the plugs out and they were black and sooty. Then the knocking started right after that ride. Is there a way to remove the possible carbon with a oil additive? Seafoam / marvel mystery oil? A fuel additive? It’s a shot in the dark but I have no idea anymore. Lol. Ever since it knocked I returned everything back to stock

 

[B40dash8]

Thanks. I tried spraying sea foam top end cleaner onto the valves and into the spark plug holes. And ran the engine alittle but it didn’t do anything. I also found this video I made when I was trying to get the valve cover back on. It shows what cam adjuster moved and what one didn’t spring down. Just a piece of video that shows it. I was having a lot of trouble getting the cover back on.

 

[B40dash8]

I adjusted the balancer chain and the self adjuster adjusted itself. It moved up alittle. It was at the bottom. But knock is still there. I was Just wondering if it’s normal to see the exhaust valve when it’s opened through the spark plug hole?

 

[B40dash8]

So I bought a mechanic’s stethoscope and the noise seems to be coming from either the bottom end or the valve cover. Not sure if the noise is just traveling or what. But still hard to pin point where it’s coming from. I did notice when I attached the shifter back on the bike without the cover that the shift rod that goes into the trans has play in it. Please See video below. I’m not sure if that’s normal or not or if it’s just because the cover isn’t on Because the bike did fall into the dirt and then the knocking appeared. So I was checking the bottom end and what could maybe cause the knock. Just not sure if that rod flexing is normal or not.

 

[B40dash8]

Thanks for the response. Man I thought I was on to something here with the noise. This is one crazy hamster wheel that’s driving me insane!

 

[B40dash8]

oh okay. Thanks. I didn’t want to battle with the valve cover today. I will try and get it done Tommorow and hit it with the small hammer. If not I’ll try and see what Pete is talking about while looking at it. That bigger wedge is stuck up. I’ll put some wd40 on it and hit it with the hammer Thanks for the picture!
View attachment 115716
[/QUOTE]

 

[B40dash8]

ah okay Pete. I was going to try karmas technique with a small watch hammer. I will try and do your adjustment with the bolts behind the cylinder today.