81 GS750E Yard find going to need lots of TLC

[Grimly]

This is something a lot of home mechanics could learn. If the manual has a torque spec for a bolt, I use it, period.

Unless you happen to have an early Haynes for the 850, where one of the torque figures given for 6mm bolts is in the order of 17 or 18 lb/ft. I wonder how many valve cover threads have been stripped out because of a single stupid misprint.

 

[jdvorchak]

I used the Factory Service Manual and I would have guessed 10 ft lbs or less. I used my 1/4 drive HF torque wrench which puts that figure right in the middle of the torque range for that wrench. My 3/8 drive torque wrench starts at 10 ft lbs. I just did a KZ1100 valve cover and that FSM called for 87 inch lbs. So I knew I was in the ball park when the Suzuki FSM called out similar torque.

Bad news or good news depending. I just broke the plastic reservoir on the front MC by applying moderate finger pressure trying to remove it from the pump. I say good news is because I found an aftermarket 5/8" (16mm) MC brand new for $25 shipped on eBay. I've bought 3 or 4 MC from that seller and always pleased. It comes with a brake light switch, new polished lever, banjo bolt and crush washers and a rebuild kit!
http://www.ebay.com/itm/271183218282

It says $28 but when I checked out it gave me a $2.89 discount! eBay says it will be here Saturday.

In the mean time I can pull the calipers and flush the brake line and have them ready for the new MC. After I got into it, the brake fluid didn't look that bad.

 

[Grimly]

Best of luck with your Chinese master cylinder.

 

[Fjbj40]

This is something a lot of home mechanics could learn. If the manual has a torque spec for a bolt, I use it, period. I always twitch torquing up brake caliper bolts and triple clamp bolts because it seems like way too little torque for the size of bolts, but that is what was designed for and that is what to use.

You're doing a great job on this bike, I am enjoying watching along.


Mark

Absolutely use the specific torques listed in the manual, there is also a handy generic tq sheet and bolt head identifier for those unlisted torques. I print and laminate them and they are on the bench during any work.

I was told by another member hear that I was a book worm know it all because I use the manual

 

[jdvorchak]

Best of luck with your Chinese master cylinder.

I hope so too. I've bought 4 of these from the same vendor and all worked perfectly. I know of one that is going good 3 years now without an issue. The quality and workmanship looks no worse than OEM to me. Fit and finish is very good to excellent. First thing I found on eBay was a plastic reservoir and O-ring for $40+ that is when I looked up my records and saw what I had bought before and got complete unit for about half.

 

[jdvorchak]

Started working on the front brakes and had to order a new MC so I took some time and started to rebuild the left front caliper. First thing I did was disconnect the banjo fitting at the MC and left it elevated. Then I remove the brake line from the left front and let it drip into a cup.



Removed the caliper and mount for a good dip in the parts washer. FYI I use only diesel fuel in my parts washer.



Here is my bench setup for removing the piston. It's an old Honda MC and a piece of a bent handle bar in the vise. I use old dirty brake fluid to push the piston out. No reason to use new clean stuff and my way of recycling old fluid.



A few squeezes of the lever and the piston is out:



Here is why I put the caliper in an old cooking pan:



after cleaning and de-rusting the caliper and piston, new seal and back together with new brake fluid as the lube. I use only clean new brake fluid as a lube for the piston. The dust boot was like new so I reused it.

When I put the pads back in I always wire brush the edges where it sits in the caliper mount and carefully apply a light coating of anti-seize to those edges ONLY. I had to literally beat those pads out of the mount with a rubber mallet. The anti-seize will prevent them from sticking.



I quit working on it for today but I did mount the caliper back onto the fork but did not bolt the brake line onto it. Tomorrow I'll do the right side and flush the brake lines. If I had found crystallized stuff in the caliper then it's time for new brake lines. Just dirty fluid and rust only in the piston cavity, so I'm just going to flush the lines with brake cleaner. Then it will be ready for the new MC and bleeding. Should have very good brakes when I'm done.

 

[hillsy]

No pitting on that piston? I'd be a bit surprised if there wasn't.

 

[jdvorchak]

Mostly rust stains and very little pitting. I was surprised

 

[jdvorchak]

Finally looking like a motorcycle again. I was doing so finish up on various wiring, brakes and got the tank and petcock clean. Thought I'd put it all together and work on some cosmetics while waiting for the front MC to arrive.



I use Yamaha Mink oil a lot on leather, vinyl, plastic to bring back the original luster to plastic parts especially. Here is the seat cover. Never mind the tear at the rear, I'll probably pull that cover off and sew that seam again.



On the instrument panels it does wonders. Safe on all surfaces but I wipe it off the metal and painted stuff.
Before



Turn signal stems





I think it makes all the difference in the word. A little of that mink oil goes a long way and is simple as wipe in on and leave it alone. Best part about it, when you put it on the seat cover it brings back the luster but is not slippery at all. As a matter of fact it adds traction because it deep lubricates the vinyl without making it slippery like silicon based products do.

 

[jdvorchak]

On chrome I use plain white vinegar and crumpled up aluminum foil to remove rust. Only takes a minute of rubbing and won't scratch the chrome like steel wool. Not perfect but looks a lot better. Then I finish up with cheap Turtle Wax chrome polish.

 

[jdvorchak]

Front MC came in a day early so I got the brakes done. Well I could not be happier. Just got back from first test ride and I'm impressed. Took it about 1.5 miles and got a couple of gallons of gas. This thing runs and rides like a new bike. Since it only has 10k miles I expected it to be good but this good? It has plenty of low end torque, very throttle responsive and quick handling. I did not hot rod it or even go much about 5k or 6k rpm. Still too early for that kind of stuff. It's been sitting for 10 or 12 years and I believe in waking them up slowly. Gear position indicator is a little flaky so I'll have to hunt down the switch and probably have to clean them up, unless it is inside the trans then... oh well. I'm just going to ride it a bit more and see if they clean themselves.

Now that I know that it runs and rides I'll work on new tires, fork oil flush, and a new chain. The chain looks good but it's 35 years old and I don't mess with old chains. Had one break on me and never want to do that again. I was young and dumb at the time...LOL

It's been a fun past couple of weeks working on her. Still have plenty more. I want to fabricate some side covers and paint the entire bike. Just haven't decided what color or scheme.

Long story short. It's a really nice running and riding motorcycle. Every shift and every turn brought a smile to my face. Can't get over how nice it really is!

 

[hillsy]

The gear position pick-up is underneath the sprocket cover and it has the neutral switch in it as well. It's a 2 bolt remove. You can scuff up the contacts to make it more "positive" and also clean up the connector block under the tank.

 

[hillsy]

BTW - good work on bringing this one back to life

 

[jdvorchak]

Thank you Hillsy! Since I have to pull the sprocket cover anyway to replace the chain I'll tend to it then. Neutral switch part is fine. Since it runs and shifts I'm ordering new tires today. It has a 130x18 on the rear but there is not much clearance on the right side. Can't get my finger between the tread and the swing arm. I'm thinking that a 120x18 would be a better choice. Originally it had a 4.00 and there is really no cross to metric size for a 4.00 rear that I can find. But I don't want to screw up the really good handling this bike has now.

My experience with these old bikes has shown me that all of the old 70's and 80's UJM do everything well. But this thing seems to do everything better than all! Better throttle response. Better acceleration and to me very quick handling. Soft ride and very comfortable seat. It does have aftermarket handlebars which certainly help. When I rode it to the gas station yesterday I found myself in a tight spot with other cars. I pulled a very tight U-turn at slow speed. Something I would never attempt on a first test ride but it felt natural and I was confident in it's handling. It actually turned tighter than I think I've ever done a slow speed U-turn. Couldn't have been a 12 foot radius. More like 8 or 10 from a dead stop! I'm not that good so it must be the bike. And yes both feet on the pegs and riding the rear brake while slipping the clutch.

 

[Nessism]

My experience with these old bikes has shown me that all of the old 70's and 80's UJM do everything well. But this thing seems to do everything better than all! Better throttle response. Better acceleration and to me very quick handling. Soft ride and very comfortable seat.

It's a GS man. Most underrated bikes ever (my opinion). Suzuki's made the best handling and best shifting bikes back then, and most made competitive power and were durable as an anvil.

Is this bike a keeper or a flipper? It seems you have put quite a lot of work into it already.

 

[jdvorchak]

It's a GS man. Most underrated bikes ever (my opinion). Suzuki's made the best handling and best shifting bikes back then, and most made competitive power and were durable as an anvil.

Is this bike a keeper or a flipper? It seems you have put quite a lot of work into it already.

No sadly I will flip it. My real enjoyment is working on them and getting them safe to ride. Usually sell them to first time riders and I strive to make them the best they can be. I have several customers who keep in touch and even bring their bike by for me to teach them how to do maintenance or repair. I tell them all to get with me if they have questions so I can make sure they don't get bad advice from "a guy that knows all about them old bikes" they met in a bar. Since I retired I don't have a lot of disposable income so I use any profit I get to buy more bikes and tools and shop consumables. I also do light repair on cars and bikes but that is maybe once every 4 to 6 weeks and I really don't like doing it. My pet peeve is older women who have trouble with their car and take it some shop and get screwed over. Mostly I make them pay for the parts but charge little to nothing for my labor. Just enough to buy cleaners or shop towels etc. Or I'll ride with them to the shop and talk to the service manager. You'd be surprised how the price comes down when the shops deal with a man and not an old woman. Case in point a woman I know called and asked if $400 was too much to fix and exhaust leak on her Rav 4. I said bring it by and we'll put it on the lift and take a look. Long story short I drove it up to a local muffler shop and he welded the broken parts back on for $60. The other shop was going to replace the entire exhaust from the header back and all she really needed was the tail pipe welded back onto the muffler inlet. She didn't even need new hangers!

 

[jdvorchak]

Ok. One more update. I rode the GS this morning and it stranded me about 1 mile from home. It just stopped running like you flipped off the ignition. Thinking it was a fuel delivery problem, I've had the petcock vacuum hose come off before, I put in on prime and tried a couple more times. No worry a nice old man and woman stopped and took me home. I got my son and he and I went to get it with the trailer. Couldn't have been 10 minutes but as we dropped the tailgate on the trailer I tried to start it once more. It fired up and I rode it onto the trailer. Got it home and had to start it 3 more times to finally get it moved around to the lift. No hint of a problem so I'll have to research that more.

But that isn't the point of this post. When I was riding it the clutch seemed to get harder and harder to pull. So once on the lift I pulled the clutch side cover. It was still coated with water/oil foamy stuff. Rest of the oil looked good. So I figured that the actuator arm and bearings were still clogged up with that mess. I cleaned it all out and put new fresh motor oil on the moving surfaces. I also pulled the pressure plate to see how the clutch plates and throw out bearing looked. They looked good so I lubed them up with motor oil and put it all back together. Clutch feels much better now but I haven't test ridden it yet, but a big time difference in feel. Not rough anymore and not too hard to pull. I hope it stays that way. There really should be a bushing in there, IMHO. I figured the biggest problem was the release rack was binding on the clutch cover.

 

[Gs1000g]

No sadly I will flip it. My real enjoyment is working on them and getting them safe to ride. Usually sell them to first time riders and I strive to make them the best they can be. I have several customers who keep in touch and even bring their bike by for me to teach them how to do maintenance or repair. I tell them all to get with me if they have questions so I can make sure they don't get bad advice from "a guy that knows all about them old bikes" they met in a bar. Since I retired I don't have a lot of disposable income so I use any profit I get to buy more bikes and tools and shop consumables. I also do light repair on cars and bikes but that is maybe once every 4 to 6 weeks and I really don't like doing it. My pet peeve is older women who have trouble with their car and take it some shop and get screwed over. Mostly I make them pay for the parts but charge little to nothing for my labor. Just enough to buy cleaners or shop towels etc. Or I'll ride with them to the shop and talk to the service manager. You'd be surprised how the price comes down when the shops deal with a man and not an old woman. Case in point a woman I know called and asked if $400 was too much to fix and exhaust leak on her Rav 4. I said bring it by and we'll put it on the lift and take a look. Long story short I drove it up to a local muffler shop and he welded the broken parts back on for $60. The other shop was going to replace the entire exhaust from the header back and all she really needed was the tail pipe welded back onto the muffler inlet. She didn't even need new hangers!

This is also a pet peeve of mine, my grandmother and sister took her 1998-2000ish Nissan maxima to a "mechanic" because it wasn't running well, he quoted her $400 to replace the CARBURATOR......... she called my dad and he looked at it, problem was a piece of $0.13 vacuum hose split.....

BTW bike looks great! :encouragement:

 

[jdvorchak]

Thanks James. I'm still not done. Today on my final test ride I went for the red line. It would not rev above 6k rpm so I still have problems. I'll start trouble shooting that tomorrow. Starts and idles great. Off idle to 6k rpm it pulls hard with no hesitation. So that narrows it done to charging circuit, air cleaner, carbs, coils, ignitors, vacuum petcock, ignition timing and mechanical advance..... Did I leave anything out?

 

[hillsy]

Ok. One more update. I rode the GS this morning and it stranded me about 1 mile from home. It just stopped running like you flipped off the ignition. Thinking it was a fuel delivery problem, I've had the petcock vacuum hose come off before, I put in on prime and tried a couple more times. No worry a nice old man and woman stopped and took me home. I got my son and he and I went to get it with the trailer. Couldn't have been 10 minutes but as we dropped the tailgate on the trailer I tried to start it once more. It fired up and I rode it onto the trailer. Got it home and had to start it 3 more times to finally get it moved around to the lift. No hint of a problem so I'll have to research that more.

Did anything else stop working when this happened? IE: dash lights went out? Could be a bad electrical connection somewhere.

Or it could be fuel starvation / vapor lock / bad tank vent. Did you open the gas cap at any stage?