1980 GS850GLT Road-worthiness Project

[eil]

I did the coil relay mod and I replaced the spark plugs with brand-new B8ES just for kicks. Previous ones were BR8ES. I may go back to those now that I have no resistors in the caps. When I tried to get a measurement off the exhaust flange, my IR thermometer was freaking out! When I stopped the engine, it worked fine. So, living proof that those resistors do something!

I now get much better spark on all four cylinders. So the coil mod was a worthwhile improvement, but didn't seem to help with the #1 cylinder. Running the engine for a minute at a little bit above idle showed 100 degrees F on cylinder 1 and around (or over) 200 F for the others.

Today, I said sod it and went for a ride. No more hanging idle. Doesn't seem to suffer a loss of power in the low RPM range when hot anymore. (And thus presumably not overheating now!) So changing out the intake boots seems to have helped. I'm calling that part a win. It still idles high, but I think that's just because I need to dial back the throttle stop screw some.

When I got back from the ride, I pointed my IR thermometer at the exhaust flanges and found that #1 was at 220, #2 was 400, #3 was 430, and #4 was 390. I understand that the inner cylinders will run hotter than the outer ones, but I'm at a loss as to why #1 runs so cool compared to the rest. It has spark. The carb has been cleaned twice now, so it's got to have fuel. I verified that the jets in it matched all the others. The fuel height is spot-on. I even swapped the caps for plugs 1 and 4, and #1 is still the cool one. If it was this cool only when idling, I could blame it on a poor idle mixture screw setting or lack of carb balancing, but this is after a good, decent ride. Dunno what to make of it!

I'll pull the plug cap on #1 again tomorrow before I run through koolaid_kid's idle mixture adjustment procedure.

[Young and Reckless]

Hi I skimmed your thread a bit and here is an issue I was having. I have had a problem with my idle running a bit rough. I set up the bike and the gas got junked up. I was replacing the plugs about once a week. Sooner if I had short in town rides. Once on the highway it ran smooth after a few miles. Put her in the shop and had the carbs rebuilt. Got it back. Ran smooth after I sat the air screws to 1 1/4 turns out. Parked her and three hours later found gas everywhere from the float bowl drain screws to the petcock and the overflow. Found it n the prime position. Started it up and ran like crap. Thought to check the exhaust 2 cylinders on the petcock side not hot one bit. Took off the plugs and saturated. Wet to the touch. Changed them and took her back to the shop. Ran great after a few miles. Anyhow still a slow leak from the petcock. So rebuild ordered and being installed. My guess is that the petcock was never shutting off and causing the bowls to overflow. And fouling out the plugs. U should check your petcock. Just a thought. But please respond with any updates.

[eil]

Hey Y&R, I do appreciate the suggestions. The petcock is old but still works. I've had the tank sitting on a shelf for weeks at a time and it's never leaked a drop, even with the tank full. I know the carb floats work. And I don't have any gas in the crankcase. (Or at least, I should say the oil doesn't smell like gas and the oil level doesn't appear to be rising.) Plugs aren't fouled, they look okay. If anything, 2, 3, and 4 are lean, I think.

MistaM kindly loaned me some vacuum gauges, so I'm going to have a try at balancing my carbs in the very near future to see if that helps. I'm not hopeful, but it's all I have to go on at this point. I'm considering raising the jet needle slightly on #3 to make it just a tad richer, but I've been reluctant to tinker with the carbs too much since everything is stock.

[boingk]

Hesitant lowend and hard starting are general lean symptoms. If you have new boots, gaskets, good airbox/filter characteristics and good spark... then see what a carb balance will do and then if not fixed...

...try going up in jet size. With a K&N filter you may well need a slightly larger mainjet.

The air screws may also need fiddling with. Seat them gently and then twist out to 1 and a quarter turns. See how she goes. Fiddle till you get the best idle and rev response.

Cheers - boingk

[eil]

boingk: I don't have a hesitant low-end or hard starting, just a colder-than-usual #1 cylinder, even after a good long ride. I still may end tweaking the air mixture screws some, but that's unrelated.

Anywho, I might have mentioned before that my battery wasn't charging. Was reasonably sure that the stator was good but the R/R was bad. A few minutes with the multimeter proved that out, so I bought the famous SH-775 on eBay. Today, I spent the afternoon swapping out the stock R/R with it. It's almost a bolt-in replacement. You'll see why when I post the pictures. Other than that, it was mostly crimping blade terminals onto wires. Charging system tests good now, and after a short ride the battery seemed to be staying charged. (Bonus: the headlight, indicators, turn signals, and brakes all seem to be much brighter now!)

Next on the agenda: The front master cylinder reservoir seems to be slowly leaking brake fluid to the outside, which means it's also leaking oxygen to the brake fluid inside. Also, the front brake switch is dodgy despite being rebuilt last winter. And finally, I've had it on my agenda to swap out my home-built brake lines with proper Rennsport lines. I already have the reservoir and a pressure-actuated brake switch, so once I get the Rennsport lines ordered, I'll be putting all those new parts on.

And then after that, it turns out I have a leaky head cylinder gasket. Wonderful. Just when I think I've fixed everything that can possibly be fixed on this bike, now I'm looking at a top-end rebuild. I was on the fence about whether to sell the infernal machine (which would have to be priced almost low as a parts bike) and get a reliable newer used runner or dump yet more money into it. Then I remember why I bought the bike in the first place: this is my learning experience. I've spent waaaay more money for parts alone on this thing than any sane person would ever pay for the whole thing. But I haven't just been buying parts, I've been buying an education. I'm not an expert by any means, but I've now done a sizeable chunk of the work in the factory service manual.

So: top-end rebuild over the winter? Bring that shyt on.

(Also, I keep telling myself that maybe I'll run across a cheap titled GS850G frame with bodywork...)

[eil]

Picture post! (Well, mostly.)



My head gasket leak. Yummy.



Pic of coil mod in progress.



Ye olde crusteh Regulatore/Rectumfire



New-to-me SH775 R/R.



Only 1/8" away from original bolt locations! Arg! What to do, what to do...



How about a little hacksaw and a little bending? Muahaha! With the R/R attached, it's still quite solid. I have no worries about it.

And before someone mentions it, yes, my battery box is surface-rusty as all hell. Yes, it's ugly. No, I'm not going to paint it.



As I'm buttoning everything up after the R/R replacement, my four-year-old daughter points to the wrenches on my workbench. "Daddy, can I fix something with your tools?" Joy of joys. I can hardly speak, but I manage to croak out, "Would you like me to teach you how to use a wrench?" She exclaims, "Oh yes, please!"

I'm pretty much beside myself at this point. She's always been curious about the world around her and always wants to try doing new things. So I explain that a motorcycle is held together by bolts and nuts. And that a wrench helps us easily take off nuts and bolts, as well as put them on. I showed her how it worked with the easiest one I could find, the upper shock nut. After I loosened it a bit for her, she had no problem using the wrench to loosen it further, take it off with her fingers, put it back on, and tighten it again to the best of her ability. (Of course, I made a point to torque it back down after the lesson.)

After that, she kept asking me what else she could fix on my bike! She's going to be quite the adept helper in just a few short years.

[rudeman]

Picture post! (Well, mostly.)



As I'm buttoning everything up after the R/R replacement, my four-year-old daughter points to the wrenches on my workbench. "Daddy, can I fix something with your tools?" Joy of joys. I can hardly speak, but I manage to croak out, "Would you like me to teach you how to use a wrench?" She exclaims, "Oh yes, please!"

I'm pretty much beside myself at this point. She's always been curious about the world around her and always wants to try doing new things. So I explain that a motorcycle is held together by bolts and nuts. And that a wrench helps us easily take off nuts and bolts, as well as put them on. I showed her how it worked with the easiest one I could find, the upper shock nut. After I loosened it a bit for her, she had no problem using the wrench to loosen it further, take it off with her fingers, put it back on, and tighten it again to the best of her ability. (Of course, I made a point to torque it back down after the lesson.)

After that, she kept asking me what else she could fix on my bike! She's going to be quite the adept helper in just a few short years.

Daughters are awesome! Mine is 19 and she's been my best friend for every second of those 19 years.

Keep at it you've come a long way. About your #1 cylinder issue - have you tried swapping the coils around? See if the problem follows the coil?

[eil]

Daughters are awesome! Mine is 19 and she's been my best friend for every second of those 19 years.

Indeed! Since I wrote that, I now have a son as well, just turned one year old. And the daughter just started kindergarten. Both of my kids are my buddies, love them to bits. They're always interested in whatever I'm doing and I try to involve them as much as I can. Too many parents these days sit their kids in front of a TV or iPad instead of doing actual parenting.

Keep at it you've come a long way. About your #1 cylinder issue - have you tried swapping the coils around? See if the problem follows the coil?

I have, and the problem stayed with #1. At this point, I'm reasonably sure that the carbs just need to be vacuum synced. I've been putting that off because I need to replace the head gasket. And I've been putting that off due to a very busy summer. Since I bought the 750E almost a year ago, the 850GL has mostly hung out in the garage this season. I'm thinking of parting ways with with the 750E come spring and then it will be time to decide whether to cosmetically refurbish the 850GL ("restore" would be too strong a word) or shop around for something more mid-size and possibly newer.

[rudeman]

I have, and the problem stayed with #1. At this point, I'm reasonably sure that the carbs just need to be vacuum synced. I've been putting that off because I need to replace the head gasket. And I've been putting that off due to a very busy summer. Since I bought the 750E almost a year ago, the 850GL has mostly hung out in the garage this season. I'm thinking of parting ways with with the 750E come spring and then it will be time to decide whether to cosmetically refurbish the 850GL ("restore" would be too strong a word) or shop around for something more mid-size and possibly newer.

I would sync them anyway. One less thing to be concerned about. That way you'll know.

[ticrazy05]

GS850 Bobber

Hi Please take a look at my bike and give me some feedback and comment.

Any help would be appreciated !

http://www.dotheton.com/forum/index.php?topic=63116.0

Thank you !