1980 GS1000 ET valve timing issue?

[cleiper]

Hi Folks,

I started working on the motor in my GS1000 2 years ago and have yet to get it to run right since the rebuild.
I pulled the barrels as the motor was burning oil, lots of white smoke.
I found the oil scraper rings were goosed so I had the barrels honed and fitted new piston ring sets after checking tolerences were ok.
I figured now was a good time to change the cam chain and valve stem seals.
During the rebuild I noted that the notches at the end of the cams were not perfectly parallel to the edge of the head while at TDC, as per the manual.
If I wanted to get them perfectly aligned I have to rotate the crank another few degrees past TDC to get them spot on, facing each other 20 pins apart.
I tried moveing one link back on the crank but this put the TDC mark well out. I am guessing about 5 Deg past TDC to get them to line up.
I fitted a DID split chain and had it rivited in place. Size 219FTSSx120
Any of you think this could be the cause of my poor running above 3K RPM?

Thanks for any pointers

Craig

[Flyboy]

Hi Craig
Welcome to the nuthouse, you will find all the info you need here, there are very knowledgable people here.

I have seen this a few times, and assuming the timing chain and tensioner are correct and installed properly it is a case of a little bit out of tolerence here and a little bit out of tolerence there and all the little bits add up, and at the end of the line you have the cams slightly out, but as you say, not enough to be corrected by moving a link.

That is one of the reasons for degreeing the cams, the cam sprockets are slotted and you can loosen the bolts and line everything up exactly as it should be.
It is more technical than that but that is the jist of it.
Not sure if it is the cause of your bad running.

Have you gone through all the essential items?
Check the valve clearences
Dip and rebuild the carbs
Make sure you are getting a good 12V to the coils.
Replace the intake boot o-rings.

Oh and by the way we like pictures, lots of them.

[posplayr]

You need a degree wheel and dial indicator to degree your cams. If you don't know how to do it it would be best to find someone that has done it before. Do a search there are some write ups.

The process involves putting a degree wheel on the crank and then using a spark plug hole cylinder stop to measure two crank positions (either side of the stop) to get TDC.

Then using the dial indicators by measuring 1/2 way between the rising (+ side ) of the cam lobe and the declining (- side) of the cam lobe you can measure where the cam lobe peak is with respect to the degree wheel(crank). You do both cams separately IIRC exhaust first then intake.

It really helps to have two people. I also find that having an accurate siting pointer gives much more accurate results as it is always clear which way to move the gear. When the pointers are less accurate you can go around and around several times before you finally arrive at the right setting.

http://www.thegsresources.com/_forum/showthread.php?t=139950&highlight=degree+wheel

[BassCliff]

Greetings and Salutations!!

Hi Mr. cleiper,

I'm more of a "general maintenance" kind of mechanic, still learning from the experts. But I can offer you the resources I have collected on my website. Maybe one of the manuals will help. Let me share some GS lovin'.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", "Top 15 Tips For GS Happiness", the Carb Rebuild Series, and the Stator Papers. Now let me roll out the welcome mat for you...



Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

[cleiper]

Thanks for the warm welcome and the advice folks.
I will post some images of my GS when I get home!
Working offshore keeps me away from my obsessions for to long.

Will give you the low down on the bikes progress when I get some.


All the best from rainy Scotland!