81 GS750E Yard find going to need lots of TLC

[jdvorchak]

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?

No the oil light came on and I think the headlight was one. I know the right flasher was still flashing. Too light out to see any other light. First thing I checked was the main 15 A fuse and it is good. I thought fuel starvation because after sitting about ten minutes it started right back up. I had left it on prime but couldn't get it to fire after a few seconds. That's when I decided to hoof it back home. That is a very busy two lane with 40 mph speed limit and virtually no shoulder as it is right up next to a drainage ditch. I knew I didn't want to park it in that ditch.... and I didn't want to have my butt hanging out into the traffic to start trouble shooting. Since I was less than a mile from home I decided the smart and safe thing to do was go home and get my trailer.

When I got it home fuel was flowing nicely but I took the cap off and squirted PB into the vent holes. I had only been riding it about 10 min at the most. So still have no clue. Like I said tomorrow I'll start trouble shooting it for real. Could also be the coils or ignitors got hot and failed but when they go usually you loose 2 cylinders not all 4. I did cycle the run/stop switch and it didn't make any difference. I had checked it's function last week and it is fine and not flaky at all.

One final thought that just occurred to me, I was in 5th gear at a steady 40 mph for about 1/2 mile prior to it stopping. No sputter or anything. Just died. Like hitting the stop switch... first thing I checked. I suppose I could have had all 4 carbs run out of gas at the exact same instant. I am anal about float settings and carb sync. Also I had a 3/4 helmet on and this exhaust is really quiet. you know what? As I'm going over this in my head I do remember it hiccup once about 300 yards before it quit. I have the tank off now and I think I'll just replace that vacuum line. It looked good but what the heck... For $1 line I'll just replace it.

[hillsy]

You should always replace fuel lines and vacuum lines on any old bike if you don't know how old they are IMO.

My bet is with the fuel cap not venting properly. You've squirted it now so hopefully it wont happen again.

[jdvorchak]

Yeah I replaced the fuel line but the vacuum line looked good. My bad. Don't know if that's my problem or not but I'm going to get some new vacuum line on it tomorrow.

[jdvorchak]

Well this either blows or I found my intermittent running problem. I replaced the vacuum line from #2 to the petcock. Hit the starter and no start. It has fuel so I pulled a plug wire and with a brand new plug found I didn't have spark. Further trouble shooting and it passed all resistance checks. Got to the signal generator. Supposed to read 250 to 360 ohm, mine reads 16k ohm.... Maybe the darn thing finally failed as it sure checks bad. Now where to find one for less than the $180 they want for new.

[hillsy]

Hmmm.....interesting.

Have a look on the SG and see if there is a number, then Google it. There will be some other SG out there that will fit / work that is not necessarily a Suzuki one. FWIW my brother had a DR650 one put on his z1300 some years ago as the z13 ones were discontinued.

[jdvorchak]

I'll look on the SG itself but I found these that use the same assembly:

This Suzuki 33110-45410 GENERATOR ASSY is used on these models and components:

1980 GS1000E SIGNAL GENERATOR 1980 GS1000G SIGNAL GENERATOR 1980 GS1000GL SIGNAL GENERATOR 1980 GS1000S SIGNAL GENERATOR 1980 GS1100-LT SIGNAL GENERATOR 1980 GS1100E SIGNAL GENERATOR 1980 GS750E SIGNAL GENERATOR 1980 GS750L SIGNAL GENERATOR 1980 GS850G SIGNAL GENERATOR 1980 GS850GL SIGNAL GENERATOR 1981 GS1000G SIGNAL GENERATOR 1981 GS1000GL SIGNAL GENERATOR 1981 GS1100E SIGNAL GENERATOR 1981 GS750E SIGNAL GENERATOR 1981 GS750L SIGNAL GENERATOR

1981 GS850G SIGNAL GENERATOR 1981 GS850GL SIGNAL GENERATOR 1982 GS1000S SIGNAL GENERATOR 1982 GS1100E SIGNAL GENERATOR 1982 GS1100ES SIGNAL GENERATOR 1982 GS750E SIGNAL GENERATOR 1982 GS750T SIGNAL GENERATOR 1982 GS850GL SIGNAL GENERATOR (MODEL Z) 1983 GS1100E SIGNAL GENERATOR 1983 GS1100ES SIGNAL GENERATOR 1983 GS1100S SIGNAL GENERATOR 1983 GS750S SIGNAL GENERATOR 1983 GS750T SIGNAL GENERATOR 1983 GS850GL SIGNAL GENERATOR (MODEL Z)

[hillsy]

You might be able to modify these ones to fit on your GS backing plate (they're off a 1st gen GSXR):

http://www.ebay.com/itm/R-86-87-1987-SUZUKI-GSXR-750-OEM-PULSE-SIGNAL-GENERATOR-WITH-SPLICED-WIRE-/121852693220?hash=item1c5efc8ae4:g:OaEAAOSwJcZWhFyw&vxp=mtr

[jdvorchak]

Since that same unit is used on so many models I've been searching eBay and found a couple that look like a direct fit. I'm convinced that pulser is a problem. As you can see it checked bad on Thursday. Well yesterday I went out to the garage and since I still had the plugs laying on the valve cover I hit the starter and they sparked. What? So I got my Fluke meter and they read 284 ohms? Ok I've been around long enough to know that means something is flaky with them. So I'm going to order a replacement.

I'm still chasing down about a half volt drop in the wiring. I did clean the ignition switch and got that voltage drop fixed. Then went to the run/stop switch. I cleaned the contacts with contact cleaner but I'm still getting a little voltage drop there. So long story short I got 12.5 volts at the fuse block and 11.87 at the output of the kill switch. Not perfect but better than the 10.5 I had before. Also seeing 11.87 at the coils instead of the 9.8 I had before I started cleaning wiring connectors. The coils just beg for the relay mod.

I know guys hate electrical problems and so do I. But really the wiring on a motorcycle is pretty simple. When you first pull the seat and the headlight out of the bucket it just looks like a mess with about a million connectors that all look dirty. It's really not that bad. Some contact cleaner and ONLY work on one connector at a time and eventually you'll get them all clean. You have to refer to the wiring diagram a lot but that's just part of it.

[jdvorchak]

I found a really good looking part on eBay for $40 shipped. So for now I'm done working on the bike until it arrives. It Should be here on the 11th.

[jdvorchak]

got the rear tire mounted and rear wheel cleaned up. I went with the 120 and I like the way it fits and looks. It had a 130 on it and I thought that looked too wide. Installed it today and pulled the front wheel/tire off and dismounted the tire. Now have the front wheel in the parts cleaner. I think I'll take some time and pull the forks and polish up the fork lowers. They aren't in bad shape but I like shiny...

[jdvorchak]

The forks weren't bad but not shiny. I spent some time with some 400 then 1000 wet or dry sand paper and followed up with my buffing pad on the bench grinder. Didn't take long at all:



The bike all put together and ready to ride:

[alke46]

She's looking better all the time. Now we just need to get some side covers on it to really finish off the look. Good job John.

[jdvorchak]

Thanks Larry. Yeah and paint that side kick stand.... I really never noticed it until I took a good look at that last pic above....LOL

[jdvorchak]

Ok I guess I did a good job reviving this old bike. I went to the gas station for a fill up and a guy there started asking about the bike. He even made me an offer to buy it! We are now negotiating the price but I'm not sure I want to sell it just yet. My oldest son, after a short test ride, even offered to buy it!

I've been looking on eBay for side covers and so far I haven't found any I would pay the asking price. I just don't understand why PO types remove those covers and don't keep them. It's not like they are hard to put back on!

[mmattockx]

I've been looking on eBay for side covers and so far I haven't found any I would pay the asking price. I just don't understand why PO types remove those covers and don't keep them. It's not like they are hard to put back on!

If the 750 covers are like my 1100E covers they use small plastic tabs to hold them on the bike. These tabs are easily broken off, resulting in side panels being put aside or lost on the road. I had one fall off while riding but got lucky because it wedged between my leg and the bike so I was able to pull off to the side and grab it.

I say sell the bike to your son, that way you can occasionally borrow it for a ride!


Mark