1980 GS1100e Cam Timing

[GuyC]

Hi all, I installed Web adjustable cams, Arias pistons, cylinders bored 3 over, head milled. Did this about 15 years ago. Never ran well at high rpm. Been sitting in my basement ever since while I raced my gsxr’s. Retired now and restoring it. Added 36 smooth bores. Ready to go but having a difficult time degreeing the cams.
Using a piston stop to first find true TDC my degree wheel numbers are inconsistent. Could a bad chain tensioner cause this issue? Out of frustration I abandoned it and found TDC placing a dial indicator on the piston. It lined up with the T mark on the ignition so I went with that. After degreeing the cams I remove the degree wheel and see that TDC is no longer lined up with the T mark on the ignition. This is after countless times. I’m quite sure my degree wheel is not shifting. Any ideas what the problem might be? Thank you

 

[zed1015]

Using a dial indicator through the plug hole won't find true tdc because of the angular discrepancy.
To find true TDC you should fit the piston stop.
Rotate the engine clockwise slowly until it touches the piston and set the degree wheel at zero.
Then rotate the engine anticlockwise until the piston again touches the stop.
Note down the degree figure difference between the two ( say 20 degrees) and halve it ( 10 degrees )
Then rotate the crank clockwise again to the stop where the degree wheel should again read zero.
Now loosen the degree wheel rotate it anticlockwise and set it at your halved figure ( 10 degree example ) before TDC.
This will give you true TDC when you rotate the crank clockwise to the TDC mark on the disc.
You should note that the factory markings on the crank case and ATD are not forced to line up exactly and you may have to install you own marks.

 

[GuyC]

Thank you for the quick response, much appreciated. This procedure is a bit different than what’s provided on the Webcam site. I’ll try it and let you know.

 

[rphillips]

Was trying to figure how to explain what zed just said. with a dial indicator the piston will stay at TDC for appx. 15 to 20 degrees.

 

[GuyC]

Yes thanks I am aware the piston stays up there and tried to compensate for it by eye but wasn’t aware for that many degrees. I’m not sure I explained my situation clearly enough. I confirmed TDC initially using the piston stop via the webcam procedure. My issue is that the degree wheel figures varied each time I performed it to confirm. Even after using the T mark and completing the cam degreeing when I removed the degree wheel at TDC I noticed that the T mark was no longer lined up correctly. I would think that my degree wheel is moving out of position when degreeing the cams but I’m quite sure it is tight, stable and not moving. I’ll mark the bolt setup and confirm this time.
I’m about to use Zed’s advice to confirm TDC and I’ll report back.
You guys are awesome! Thanks much.
Guy

 

[zed1015]

Was trying to figure how to explain what zed just said. with a dial indicator the piston will stay at TDC for appx. 15 to 20 degrees.

Yes! The crank will rock through several degrees going over TDC ( and BDC ) and any vertical movement of the piston will be inperceptible to the dial gauge.
This will be the root cause of the degree reading inconsistancy ..
Reading crank rotation from the degree wheel in relation to a fixed point in the piston travel is the only way to determine true TDC.

Webcam do quote the same procedure to find TDC but their explanation makes it appear a little less straight forward...
They are zeroing the pointer before fitting the stop so you end up having a reading before and after the stop which you have to add together then split.
Either way gives the same result.

 

[GuyC]

Thanks gents. I have the cams degree completed and just need to confirm piston to valve clearance. Hopefully I’ll have my baby running this week. Can’t explain how comforting it is to retrieve such invaluable advice when needed. Thanks again.
Guy

 

[GuyC]

Hi gents. I found TDC using the piston stop tool, completed the degreeing the cams, confirmed piston to valve clearance, adjusted the valves, removed my degree wheel only to find once again that the T mark on the ignition plate is not even close to lining up with the TDC mark. I attached a picture. This time I marked the bolts and washers that I used to put mount the degree wheel, so I am certain that it didn't move out of alignment when turning the crank. Could TDC be correct with the T mark being that far off from the line above it?
Guy

 

[zed1015]

Is the alignment difference the same amount as when you first posted the problem ?
If it is then you are either your degreeing procedure is flawed or the marks don't align at true TDC.
If the latter is the case then there could be several reasons.
A few off the top of my head ...

1. The factory marks are incorrect ( friday aftenoon job).
2. The ADT is the wrong one or isn't located correctly on the crank.(worn or bent location pin etc)
3. The crank is twisted.

To check for crank twist use the piston stop to find TDC on the opposite cylinder to see if the result changes.
I presume you degreed on number 4 so check on number 1 as that should show the biggest difference .

 

[GuyC]

I believe I found the problem. The pic I provided in my last response shows a 17 millimeter washer has two slots in the back of it that sit on top of two pins that stick out of the timing advance assembly allowing it to mate to the assembly when the bolt is sent through it and tightened. This allows you to turn the crank with a 17 millimeter wrench on the washer. The slots in the washer are larger than they need to be and provide a loose sloppy fit over the pins allowing the washer to rock back and forth 4 to 5 degrees. When you tighten it down with the stock bolt that slips through the washer everything is fine turning the crank. However, when I extend the degree out about 3 inches using a spacer and longer bolt to make room for me to put the wrench comfortably behind the wheel to turn the crank regardless of how tight I make the bolt, the washer rocks loosely on the pins.
I decided to place the degree wheel flush without extending it and turn the crank using the counter shaft on the opposite side so as not to disturb the degree wheel washer Setup. I’m away for a few days. I’ll continue when I return and report back.
thanks again.
Guy

 

[salty_monk]

Pretty sure there is a very comprehensive post by Posplayr on this process somewhere for the 1100E. (His was an 83). Pictures may be missing these days though (damn you Photobucket....)

 

[rphillips]

If eng. is still in bike, just put the bike on center stand, trans in 5th, & gently bump the rear wheel forward, it in turn gently turns the crank & degree wheel forward. For me, when you get the feel of it, much easier than turning with wrench.