Camchain 1 tooth off?

[Jeepert88]

What would be symptoms of a camchain that skipped a tooth on the camshaft?

 

[fredintoon]

What would be symptoms of a camchain that skipped a tooth on the camshaft?

Hi Jeepert,
my best guess would be that the bike would be a swine to start and would run like shit. (and not like shit off a red-hot shovel, either.)
Although the only way the camshaft could have skipped a tooth (as opposed to being assembled one tooth wrong) is if the cam-chain was running so loose that the engine was about to frag itself.

 

[Jeepert88]

The thing is, I recently changed the camchain guide. New gaskets, cleaned carbs 3x, cleaned k&n pods, exhaust is air tight and valves are set a bit more loose than spec.

Running bs34's on a 82 heritage with kn pods and straight pipes, powerdynamo pma, 45 pilot n 145 main, no battery.

It ran just fine before I took apart the top end....

 

[5twins]

You can check it by just removing a couple covers ......

http://www.650motorcycles.com/CamTiming2.html

 

[Jeepert88]

Will do this when I have time. Is "carb popping" always timing related?

 

[5twins]

By "carb popping", if you mean the carbs popping out of their holders, yes, that usually is timing related. If you mean popping out the backs of the carbs, like mini backfires, I suppose that could be timing related but it's usually a lean indicator. Your jetting seems rich enough, maybe you've developed an air leak?

 

[Jeepert88]

Yeah I mean little backfire and puffs of smoke out the pods. I know the outside of the carbs boots are old and cracked but I can't see any cracks on the inside. Maybe I should order some new ones before tearing open the engine

 

[Jeepert88]

But if I would have a lean mixture, how is it that my plugs are coated in black "dust" ?(looks carbon fouled to me) that would only be possible with rich conditions right?

 

[5twins]

Usually, yes. But, if you did that plug check shortly after starting with the choke, that could be causing the black plug reading. Using the choke blackens the plugs right up and it can take a good ride, like 10 or 15 miles, to burn them clean again.

 

[Jeepert88]

It ran like shite without choke, idle would go way up so I ran it with choke only. So that explains the black plugs. It's only 5-10 minutes to work so I figured that wouldn't kill me bike. Guess I'll order some boots then, cause on this island nothing is in stock....

I thank you for your help

 

[5twins]

Idle speed staying high like that is another lean indicator. Yes, I think you need new intake manifolds, sounds like yours are sucking air.

 

[Jeepert88]

Just blocked off 1/3 of the pods with duct tape, didn't make a difference. But finding those ratios with duct tape would be a Harvard study on its own.. Imma call the only parts shop on the island to see if I'm lucky. Thnx a lot for the help

 

[5twins]

Something else you should know is that the pleated K&N style pod doesn't work well or right on these CV carbs. The pleated element design causes turbulence in the air flow and that messes with the slide lift. If you want to use pods, the straight foam UNI version is the best choice.

 

[Paul Sutton]

If you are still concerned about the cam chain being out by one tooth then do the following. Set the engine at TDC and remove the chromed cover where the timing advance would be on older XS models. There is a hole drilled in the end of the cam shaft which held a metal pin for the timing advance mechanism. This hole will either point vertically up or vertically down if the cam chain is correct. You can fit a 2.5mm, or was it 3mm, drill bit in the hole as an indicator/pointer.

 

[5twins]

That's what that link I posted explains.

 

[Jeepert88]

I'll try this until new parts arrive...