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Old 07-04-2013, 02:38 PM   #1
Triam OP
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Question GS850 Fix-up

Ok, so I've bought a 81 GS850G and I'm fixing it up. When I bought it it squeaked especially at very low RPMs, even more so when the bike was only turning over. It had a knock so I took off the cover and checked the valves. Every single valve was out. maximum clearance for this bike on both exhaust and intake is .003, and I had one at .011 Tomorrow I'll go and pick up new shims.
Point #1 The person I bought it from said that he'd ride it for a while and then it'd bog down and die and then he'd let it cool off and it'd ride great again.
Point #2 When I took off the valve cover most of the camshaft was bone dry. I coated the cams with oil manually, then the bike turned over much faster than before, and that squeak was much quieter. You can see from the picture of the cover that there was just debris that looked like worn shim and cam shavings, and you can see how dry it was.


This is the top of the engine after my manual oiling job.

Last fotos: cam shafts


So should I just assume that it's an oil pump problem, or clogged lines, or something else?
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Old 07-04-2013, 02:47 PM   #2
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Question rebuild?

So, I forgot to mention that two of the 4 spark plugs were covered with oil when I pulled them, and I think they had less than 300 miles on them. Here's another picture:

You can see the compression readings I got in the photo of the paper above, does this mean that I need to do a complete top end rebuild or is it the valve guides, or is this something that can wait until the end of riding season when having a bike that works isn't as important?
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Old 07-05-2013, 02:19 PM   #3
Andyinhilo
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You definitely have an oiling problem. The early 4-stroke Suzukis were low-pressure, high volume systems, as all of the bearings, except the cams were balls or rollers. I would suspect a bad pump, or maybe a badly clogged filter. There is a flow switch on the crankcase behind the cylinder, and if that got stuck, it would starve the top end of oil, IIRC.
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Old 07-05-2013, 08:15 PM   #4
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Quote:
Originally Posted by Andyinhilo View Post
You definitely have an oiling problem. The early 4-stroke Suzukis were low-pressure, high volume systems, as all of the bearings, except the cams were balls or rollers. I would suspect a bad pump, or maybe a badly clogged filter. There is a flow switch on the crankcase behind the cylinder, and if that got stuck, it would starve the top end of oil, IIRC.
Thanks for the response.

Accordingly I took off the oil pan to check the screen and it had a few bits of something black, but nothing that would block the flow. I cleaned them off with an air nozzle. The filter was a brand new K&N and the oil was also new. The flow switch has been seriously messed with so that it no longer works. I just ordered one today that's OEM. Take a look at the one that was on it.





It didn't work because there was no oil flow past where the switch had been relocated Also, the switch was broken.

I pulled the clutch so I could get to the oil pump and visually inspected the pump like it says in the Haynes manual. I found two nicks and I'm not really sure if they're the culprit or not.





They look small to me, but I'm very new to bikes, so if those of you who know could shed some light on this I'd appreciate it.
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Old 07-05-2013, 08:32 PM   #5
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K, so moving along.

The manual says that there are supposed to be 2 dowel pins locating the pump, but they're not there on mine. I'm wondering if mine is a different pump that they went to later. It has a boss on one half of the pump and a relief to fit the boss on the other half. Did this year had that boss instead of dowels? Here's a picture of the two halves.



I measured the oil pump and the clearances between rotors were fine. There's a measurement in the manual called "rotor endfloat" and I wasn't really sure how to measure it. I tried to imitate the picture and measured from the mating surface to the rotors. This measured out as .0055 and the "rotor endfloat" can be as much as .006, so maybe that's the culprit and I need a new oil pump. Here's the picture of how the manual shows it. I hope this isn't violating copyright.



If anyone knows something that I'm missing please post!
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Old 07-06-2013, 12:39 AM   #6
willis 2000
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hold the oilpump in yer hand
rattle the shaft up and down
if ya don't have the feel
get a ruler so ya can hear the clack
not likely yer only problem judgin' off them cam lobes
musta been that valve ya spoke of and still bought it
research after the fact
that motor will either cost a lot
or rattle and hum
put it back together
get it goin'
resell

credit u2
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Old 07-06-2013, 12:47 AM   #7
willis 2000
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fine pics
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Old 07-06-2013, 01:03 AM   #8
willis 2000
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tell me tell me
wont't ya tell me
and then tell me again
wait this year out
that old stuff, ya don't want it
there's one in a museum or a coffee table book
four of everything
in the sixties, bill cosby revved us up
everything's gonna be dual

credit styx
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Old 07-06-2013, 08:35 AM   #9
Triam OP
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Quote:
Originally Posted by willis 2000 View Post
hold the oilpump in yer hand
rattle the shaft up and down
if ya don't have the feel
get a ruler so ya can hear the clack
not likely yer only problem judgin' off them cam lobes
musta been that valve ya spoke of and still bought it
research after the fact
that motor will either cost a lot
or rattle and hum
put it back together
get it goin'
resell

credit u2
What valve are you talking about? The oil pressure sender?
Honestly, I'd rather do a complete rebuild than fix it and sell it. You saw my other thread. I bought it less to ride it, and more to have something to do. I've never done a rebuild, so it'd be fun. It'd run like a champ afterwards as well. Once this lube issue is fixed I'll step back and decide what the next thing is that I do.
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Old 07-06-2013, 09:03 AM   #10
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Before you get any farther I'd find some local expertise. You may be barking up the wrong tree about an oiling problem . The cam lobes look good.
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Old 07-06-2013, 09:34 AM   #11
willis 2000
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Quote:
Originally Posted by Andyinhilo View Post
You definitely have an oiling problem. The early 4-stroke Suzukis were low-pressure, high volume systems, as all of the bearings, except the cams were balls or rollers. I would suspect a bad pump, or maybe a badly clogged filter. There is a flow switch on the crankcase behind the cylinder, and if that got stuck, it would starve the top end of oil, IIRC.
this guy mentioned the flow switch.
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Old 07-06-2013, 09:36 AM   #12
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Oil pressure switch.That's for the oil pressure light. Does NOT control flow.
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Old 07-06-2013, 12:26 PM   #13
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Quote:
Originally Posted by joexr View Post
Before you get any farther I'd find some local expertise. You may be barking up the wrong tree about an oiling problem . The cam lobes look good.
The guy I bought it from said it developed the squeak recently, so that's why he decided to sell it. He didn't have time to go through it so he decided to sell it. I think that this is a new development so that's why the cams look so good. Local expertise would be nice. I don't know anyone local though.
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Old 07-06-2013, 12:30 PM   #14
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Originally Posted by joexr View Post
Oil pressure switch.That's for the oil pressure light. Does NOT control flow.
Yep. Nevertheless, I ordered one because once I get everything put together it'll tell me if the problem is between the pump and the switch or between the switch and the cams.

One more thing. I blew air through the oil passages (I don't know what they're really called) and I was able to verify that there wasn't anything clogging the system, or if there was it was blown somewhere else.
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Old 07-06-2013, 12:34 PM   #15
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It tells you the pump is pumping and nothing more.
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