1980 GS850L Mechanical Questions

[arbarryf]

I just finished adjusting the valves and rebuilding the carbs and I encountered a few concerns. To begin with, the valve cover was leaking a considerable amount of oil onto the engine - enough to splatter onto the fender, my pants and everywhere else. When I took it apart, I noticed tons of gasket goop. I adjusted the valves (7 0f the 8 were off). I now have one intake at .006, one exhaust at .009, and all the rest at .008. Bike does seem to be smoother. I lapped the valve cover and breather cover flat prior to re-assembly and it doesn't seem to be leaking any more, but I do see some oil on the gasket itself, but this is probably due to the fact that I had to use a paper gasket.

The carb rebuild went fairly smooth with two exceptions. I could not get the air pilot screw out of the #1 carb so I just left it alone, and when I went to tap the float pin out of the #4 carb, the two posts on the body fell off. Upon inspection it was clear that they had previously been JB welded. I cleaned them up and re-JB welded them and hopefully they work ok. I changed the tach cable and seals and it's not leaking or causing the needle to jump around on the gage anymore.

Now the questionable stuff. The speedo had quit working and based on a prior post, I replaced it. I had to loosen the nut on the front axle to rotate the speedo unit enough to be able to loosen the cable. After replacing the cable, during a three mile test ride the speedometer is now working again, but there is a hellaciously loud whining noise (almost like a light grinding noise) coming from the speedo gage. I realize now that the subtle whine I was hearing before that I mistook for for a vacuum leak in an intake boot was actually coming from the speedo gage.

When I took the tank off, it was about 1/4 full and I had some gas pour out of the fuel line after it was removed. I thought the petcock would not permit fuel to leak out, so I suspect I may need a new petcock. It is the type that does not have a lever - just a screwdriver slot. Also, when I removed the boots between the carbs and the air filter box, all four boots looked like they had been on fire - all melted down. Anyway, after I put everything back together I noticed some fuel dripping out from the chrome air box cover on the left side.

So after all that, here are my questions:

1) What's up with the speedo? Could I have overtightened the front axle nut and would that have caused the loud whine? I don't believe these gages are made any more, so I need to make this one work.

2) Do I need to replace the petcock? I know they can be re-built, but a whole new one is only $59.00.

Thanks for any insight.

Barry

[REBRIDER]

Well I may be a F.N.G. like you but I just resolved a couple of issues exactly like yours. Yeah your petcock is bad ,don't screw around with it or you will end up with a crankcase FULL of gas like I did,scary and worriesome indeed. I tried the kit route,don't go there, get a new Suzuki petcock. I also had to replace my box to carb boots,about $8 ea. Made it Easy to put back together.

[chuckycheese]

Petcock

If you do a search, you'll find a zillion posts regarding the foul and infamous 1980 petcock...they're awful and the only reason they used them was because the engineers left very little room for a petcock so they did the best they could....and engineered a really small, crummy petcock.

You can buy another one and it will probably work well for quite awhile. If you want one that will last for a long, long time...and get a very useful 'reserve' to boot, get a Pingel. If you decide to do that, try searching for "Pingel project completed" and you'll get all the scoop you need in order to order the right one and install it correctly.\\/

P.S. If you go the Pingel route...don't forget the adapter!

[arbarryf]

Thanks for the tips - I'm going to go ahead and replace the petcock. What about the speedo - that one's got me completely baffled. By the way, after I put the new cable on the speedo was working - just making the terrible noise.

[BassCliff]

Hi Mr. arbarryf,

When my speedo was making noise I disconnected the cable, took the gauge off, turned it upside down, and squirted a little of my favorite household lubricant in it. A silicon lubricant might be a little neater rather than 3-in-1 oil or WD40. It hasn't made a peep since.

Just a reminder, have you stopped by my little BikeCliff website and picked up your manual?


Thank you for your indulgence,

BassCliff

[arbarryf]

BassCliff,

The truth is, since I bought this bike I've spent more time on your website than on this one. Not only have I downloaded the manual, but I printed all the tutorials. While I'm not a mechanical dummy, I'm certainly no mechanic, but your tutorials made the valve adjustment simple enough even for me. Now that I've been through the work, I realize the amount of extra time you spent taking all the pictures while doing the work. All I can say is thank you. Eventually I will use all of them, and the ones you have links to as well.

One thing that continues to puzzle me though is the wear on the shim/bucket. In the tutorial you say to increase the clearance by using thinner shims, which I did and the difference is noticeable. The only thing that confuses me is that it seems like either the shim or the bucket would wear, causing the gap to open, not close. The only thing that makes sense in my mind would be the actual valve or seat wearing to cause the gap to close - is that what's actually happening?

Also, I work in the plastics industry, and when we take the end cap of an injection barrel, it has to be lapped when reassembled or it will leak. I lapped the breather and the valve cover. The breather seemed to be pretty flat, but the valve cover had about 2 tenths of gap (high in the middle). It took nearly three hours to work it flat, mostly due to the fact that there is very little room for movement.

I noticed too that if you turn the shim tool a little sideways when you're pushing down it has less of a tendency to slip off.

I'll buy a replacement petcock and then I think I'll have a mechanic at the dealer do a final carb tuning. I got it close enough to ride, but it's still not quite right, and the finer adjustments are beyond my skill. Also, I bought replacement intake boots and their diameters are smaller than the ones that were on there. The new clamps that came with them tighten all way down and they'll still turn. Same with the old ones. I made some shim stock by rolling up some tin foil, but I want to find some slightly smaller clamps.

Prior to the valve adjustment I felt like I needed to shift at 3,500 rpm and by 4,500 I felt like it was wound out. This morning I was shifting at 5,000 rpm. Big difference! Anyway, much more work to do - probably brakes next.