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Offline coolhand

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Re: Resetting cam chain tension - enough space btw frame and tensioner?
« Reply #10 on: December 04, 2018, 12:09:41 PM »
Darn....

anyone need a brand new torque limiter for setting the cam chain tensioner correctly?    :005:

Well, one can never have enough tools....  :152:

Thanx for good help, I will post again if the motorcycle god fails med. CHeers!!!! 

Offline eps

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Re: Resetting cam chain tension - enough space btw frame and tensioner?
« Reply #11 on: December 04, 2018, 09:28:41 PM »
best of luck - Marks service book is good and there is a good you-tube video showing the adjustment on a 800 Tiger - very very similar - just a little less clearance.  Take your time and loads of pictures for cable routing and wiring.  :002:

Offline SOHUTAA

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Re: Resetting cam chain tension - enough space btw frame and tensioner?
« Reply #12 on: January 12, 2019, 09:50:05 PM »
*Originally Posted by eps [+]
best of luck - Marks service book is good and there is a good you-tube video showing the adjustment on a 800 Tiger - very very similar - just a little less clearance.  Take your time and loads of pictures for cable routing and wiring.  :002:


Regarding the video on youtube, is it a 800 after 2015 having a setting of the camshaft gears? If this is the case, I want to enjoy the shortcut of this video.

The only video found on the subject, is a tiger 800 before 2015, having only 2 single holes in the pinion, so no adjustment possible

Offline unsubtle

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Re: Resetting cam chain tension - enough space btw frame and tensioner?
« Reply #13 on: January 12, 2019, 10:44:53 PM »
I've done the job both ways: Mark's way at 20k miles onwards, and retiming the factory way at 50k (although actually I used a torque screwdriver set to 0.6Nm as it was cheaper and more versatile than the factory tool). With Mark's way, I didn't find that the alignment grooves on the camshaft ends were in line unless I physically twisted them in to line against the pressure of the cam-chain tensioner (putting some slack in to the length of chain between the camchain sprockets. Doing the job as per the factory manual with the factory tool did get them in line without any problems, implying that there was a real change in cam timing. Hence I would definitely advise using the factory tool.

Having said that, I rode the bike for ?40k miles with the cam timing out, and the valves did not hit the pistons nor was there any shortage of stomp.

To answer one of OP's questions: the tool is ball-ended so that it clears the frame.

Offline SOHUTAA

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Re: Resetting cam chain tension - enough space btw frame and tensioner?
« Reply #14 on: January 12, 2019, 11:38:26 PM »
Exactly the same opinion as you, as already expressed in the previous page.

Offline Rfsci

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Re: Resetting cam chain tension - enough space btw frame and tensioner?
« Reply #15 on: January 13, 2019, 08:08:09 AM »
The tension applied to the cam chain with the jig is equivalent to when the engin is running with oil pressure!


The cam tension when running is a combination of the force of a spring and the Oil pressure.

When the engine is not running the tension on the chain (without additional added tension like the tensioning jig) Is not enough to preform cam adjustments, as there is a possibility of the cam lifting a bit when the valves nearest the chain open.

Or to put it another way. Without the cam chain being at the correct tension the cam clearances you measure near the chain will be bigger than they will be if the tensioner jig was fitted! This means that larger shims will be fitted than required..
 :019:

Offline CaptainTrips

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Re: Resetting cam chain tension - enough space btw frame and tensioner?
« Reply #16 on: January 13, 2019, 04:28:21 PM »
*Originally Posted by Rfsci [+]
When the engine is not running the tension on the chain (without additional added tension like the tensioning jig) Is not enough to preform cam adjustments, as there is a possibility of the cam lifting a bit when the valves nearest the chain open.

Or to put it another way. Without the cam chain being at the correct tension the cam clearances you measure near the chain will be bigger than they will be if the tensioner jig was fitted! This means that larger shims will be fitted than required..
The cam chain tensioner has a ratchet system that prevents it from backing off. Are you suggesting that valve clearances cannot be checked correctly without using the OEM cam chain tensioning preload tool? That would be news to me.
"The test of the machine is the satisfaction it gives you. There isn't any other test."   --   Robert M. Pirsig

Offline Rfsci

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Re: Resetting cam chain tension - enough space btw frame and tensioner?
« Reply #17 on: January 13, 2019, 05:03:14 PM »
The chain is only at full tension when the oil pressure has built up.

The ratchet in conjunction with the spring provides enough tension for the engine to start and not to jump over the sprockets(without the ratchet a badly worn chain would almost certainly jump)

How much would the errors be in the valve clearances, depends on the cam bearing sloppiness, the bending force on the cam for the middle valves, to be honest I wouldn't expect much but would play safe.

(The valves will try to push the cam upwards, the cam tensioner pulls it down.)

Comments on hear have indicated the chain tension affects timing, no it doesn't timing is only effected by worn chains. Ie the chain under tension being pulled by the crank, in turn turning the cam, this part of the chain that does this is the opposite side to to the tensioner.

Offline unsubtle

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Re: Resetting cam chain tension - enough space btw frame and tensioner?
« Reply #18 on: January 13, 2019, 05:15:31 PM »
*Originally Posted by Rfsci [+]
Comments on hear have indicated the chain tension affects timing, no it doesn't timing is only effected by worn chains. Ie the chain under tension being pulled by the crank, in turn turning the cam, this part of the chain that does this is the opposite side to to the tensioner.

The point of using the factory tools is to set the chain tension so that you can re-install the cams with the right timing. The unofficial method assumes that timing will not change. In fact it does change - I would estimate that the by about half a tooth, which is a significant variation. This is not speculation, it is observation from actually doing the job. Using the unofficial method, I found that with the crank pinned, the alignment bar could not be fitted in to the cams without forcing them against the tensioner, inducing slack in the run between the cams. This is clearly incorrect timing, and was fixed by doing the job the official way.

I can't parse your second sentence.

Offline CaptainTrips

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Re: Resetting cam chain tension - enough space btw frame and tensioner?
« Reply #19 on: January 13, 2019, 09:51:49 PM »
All that I can tell you is that I used Mark Barrett's method to set my valve timing at 20k and I ended up with a smoother engine and was satisfied with the result. I did find that I had to twist the bar slightly to get it into place on the second camshaft, but I don't think that it made any appreciable difference. And now that it is set, I am not going to worry about it.

Thinking back, I did fiddle with it a bit. What I found was that the cam sprocket adjustment screws were right at the end of their slot on one cam. What I did was, with the 7mm bar in place holding the cams, I pulled the crankshaft lock pin and then worked the crank back and forth a bit to center the adjustment screws and even out the tension. Then I reinserted the crank lock pin and torqued up the adjustment screws.
« Last Edit: January 13, 2019, 10:30:23 PM by CaptainTrips »
"The test of the machine is the satisfaction it gives you. There isn't any other test."   --   Robert M. Pirsig

 


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