'79 GS 850 restoration

[spacepirates]

Well, I'm still wet behind the ears when it comes to the GS series of bikes, but I figured I'd post in here my plans to get some constructive criticism going. I have two other bikes, a 2002 Suzuki Savage and a 1978 XS750. The XS is currently under the knife getting a front end from a '92 CBR 600 and the savage is my daily ride.

I picked up my GS850 off craigslist a few days ago, in running condition albeit with some issues. Cosmetic issues include badly faded paint on the tank, holes in the exhaust, missing contact breaker cover (ignition cover), and missing left side cover (if you've got a spare one, i'm still looking for a replacement!).

It does have some running issues. Kind of hard to explain, but it feels like it hiccups or cuts out for less than a half second fairly often. Not enough to make it unrideable (I was able to get it home) but enough to make me question its reliability.

After it was safely nestled in my garage, I dreamed up a list of mods/maintenance actions that I should take before I start putting this bike through its paces:

- New fluids (crank oil (probably 5w-40 Rotella Syn), middle gear, final drive, gas)
- New manual petcock
- Carb clean
- Intake O-rings
- Carb boots (if needed, I'd like to avoid this though)
- Clean/replace air filter
- Replace mufflers
- Clutch springs (if needed)
- Lube throttle/clutch cables
- Reseal airbox weather stripping
- Upgrade to electronic ignition (Dyna S)
- New coils (again, Dyna)
- New spark plug caps
- New spark plugs
- Replace brake lines with stainless steel lines (just front)
- New brake pads front and rear
- Revitalize the wiring/electrical
- Check the stator is in working order
- Add an inline paper fuel filter
- Adjust the valve clearances

A long and expensive list, though I think I've already purchased the big stuff (exhaust, brake pads, valve shims, ignition, coils).

So far, in my one day of having the bike I've stripped the bike down and checked clearance on the valves, all of which were tighter than my smallest feeler gauge (.004"). Six shims were 2.80 and two were 2.75, so I ordered four 2.75 shims (the other two can be re-used from the other valves) and two 2.70 shims. I hope I did that right... I also got around not having a special shim removal tool. I took out the tensioner (if that is what it is called) between the two cams to give me some slack, then I removed one set of cam bearing covers at a time to allow me to move the cam up about an inch without removing it from the cam chain AND without moving the other cam, so I won't lose timing. pop the shims out, bolt the bearing cover back in, wash/rinse/repeat on the other cam. It takes a bit longer, but it is easy to get the shims in and out.

Wiring will be the big time sink for me, as I'm the least familiar with that part of the GS (the XS has shim type valves, albeit 29mm and not 29.5mm diameter). Have any tips? I think I read somewhere about adding another good ground connection, adding a relay/fuse, and removing something from inside the headlight bucket, but I can't recall.

I know it is poor form of me to post without pics, so I'll try and get those to you when I can. I didn't even get a single picture of the bike before I got it taken apart! And of course, after that, my hands were all oily and there was so much more work to be done!

Let me know if you've got any pointers/tips or if I've got the wrong mindset about what mods I'm doing. My goal is to have a very reliable bike that I can ride pretty much indefinitely.

 

[Nessism]

It's good to see someone new here that understands the importance of maintenance. Keep going with all that. As for your valve work, I'm afraid you are making the job more difficult than necessary (there is no need to remove the cams). Please check this link for tons of good info, including a factory service manual download and instructions on how to adjust your valves without using any special tools...http://members.dslextreme.com/users/bikecliff/ Oh, and for heavens sake, get the right feeler gauges. You can't do the job properly using the wrong tools.

Fuel filters, particularly the paper type, add flow restriction and are bad in a gravity feed fuel system. A lawn mower (type) filter will work but it's best to just clean your tank if there is any debris in the system. And read up on how to improve the charging system and make it more reliable. Rewiring the system and adding a better combined R/R unit is a step in the right direction.

Good luck and keep going...

 

[spacepirates]

I've been going off of BikeCliff's website for a lot of information, great stuff!

I had just emailed Mr. Steve about the valve spreadsheet, and found out that I've made a mistake! Inches are not millimeters! I thought for some reason the valve specs were .003 to .008 *inches* when that they are in *millimeters*! At least I caught this before installing the new shims. Ordered some new feeler gauges to clear up this mess... Bah, and after I've already ordered new shims...

I'm surprised you're against paper filters. Given a large enough surface area of the paper element, I wouldn't expect them to restrict flow that much and they catch a lot more than the plastic mesh filters. Rust and debris are rather persistent and even after a good washing and treatment, rust can crop up again. I've been using them for a few years on my other (gravity fed) bikes with no (known) issues, but that might be comparing apples to oranges. I'll take a second look in the tank and then probably take your suggestion.

I don't think I'll *replace* the R/R unit unless it needs to. My wallet is feeling a little thin after the initial bike purchase and the maintenance/ignition upgrades. Once I'm more content about the health of the engine, I'll run through the stator tests and see what I find. Cleaning up the wiring is a minimum, and I just read about the coil relay mod so that will most likely happen.

In my email with Mr. Steve he referenced my post here and I realized add to a few things:
- Manual petcock because it has one less thing to fail (on my savage, the vacuum petcock was a source of problems for a lot of people)
- Carb clean... Depending on how the carbs look once I get them apart, I very well might leave them together as a single unit. I've also had good luck using lemon juice and pinesol over straight carb cleaner
- Intake O-rings... already purchased a set off of cycleorings with carb o-rings and stainless hardware.
- Air filter... Should this be replaced if it looks basically new? I pulled mine out and it didn't look dirty at all.
- Mufflers... I'm going to try a cheap universal muffler (EMGO shorty, with an added glasspack) before I think of more expensive 4-into-1 solutions


Aside from BikeCliff's website, is there a sort of "Table of Contents" kind of link that has references to forum threads on the topics? I.e. a single page I could go to that has links to forum posts about valve adjustment? Each forum kind of has it's own set of rules and style of organization, I'm just trying to understand how this one works. When in Rome do as the Romans do and all that...

Thanks!

 

[DannyMotor]

I don't think I'll *replace* the R/R unit unless it needs to. My wallet is feeling a little thin after the initial bike purchase and the maintenance/ignition upgrades. Once I'm more content about the health of the engine, I'll run through the stator tests and see what I find. Cleaning up the wiring is a minimum, and I just read about the coil relay mod so that will most likely happen.

Trust me. If youre putting all that fancy electric ignition setup in a 30 year old bike you want to at least put a good upgraded unit in. Shindengen Honda R/Rs are common and practically bulletproof. I just got one off ebay for 20 bucks shipped and my lights and spark are all about 3x stronger than before. That and my battery charges now... haha.

Do a search... theres a list of compatable 6 wire units and a very good writeup on the Basscliff site.

Again... welcome and thank you for being practical and having the sense to tackle the big important things first!!

 

[spacepirates]

Trust me. If youre putting all that fancy electric ignition setup in a 30 year old bike you want to at least put a good upgraded unit in. Shindengen Honda R/Rs are common and practically bulletproof. I just got one off ebay for 20 bucks shipped and my lights and spark are all about 3x stronger than before. That and my battery charges now... haha.

Do a search... theres a list of compatable 6 wire units and a very good writeup on the Basscliff site.

Again... welcome and thank you for being practical and having the sense to tackle the big important things first!!

Hm... I was under the impression an R/R upgrade would be closer to $200, not $20. It seems I have even more to learn. I'd gladly pay $20 for peace of mind.

 

[GateKeeper]

Hm... I was under the impression an R/R upgrade would be closer to $200, not $20. It seems I have even more to learn. I'd gladly pay $20 for peace of mind.

you were probably thinking of the stator......

and depending on where you get it, it does not have to be 200 bucks...

and have a look here for more info in the R/R

http://www.thegsresources.com/_forum/showthread.php?t=134690



.

 

[spacepirates]

you were probably thinking of the stator......

and depending on where you get it, it does not have to be 200 bucks...

and have a look here for more info in the R/R

http://www.thegsresources.com/_forum/showthread.php?t=134690



.

Indeed I was. I'll definitely upgrade the R/R now, just got to find an appropriately priced candidate on ebay.

 

[DannyMotor]

On ebay search "shindengen" then narrow it to honda... then you can cross reference model numbers with those in the list in the link above. Even some atv and scooter ones will work.

 

[Nessism]

BTW, short cuts are long cuts when it comes to cleaning the carbs. Even if they look decently clean you can be sure the rubber O-rings are hard and brittle. Best to break them down all the way, dip the various parts, and reassemble with new rubber.

 

[spacepirates]

So... Would this R/R work?
http://www.ebay.com/itm/82-Honda-VF...es&hash=item4d00ccdcf5&vxp=mtr#ht_1436wt_1163

SH 541-12

From the Stator R/R compatibility page:
Honda VF750/1000 Shindengen SH541-12 12V xx Amp 14.4 V(about 1/8" wider & slight mod to fit GS)

 

[DannyMotor]

Haha... looks like you bought it...

That's a 7 wire unit... so, be sure you look up BassCliff's directions on wiring that in. The 3 yellows go to the stator, and then I believe you have 2 ground wires, and 2 hot-wires... I was sure to get a 6 wire unit... 1 ground, 1 hot, 1 sense (wired to brake switch orange), 3 stator.

Let us know how it works out!

 

[spacepirates]

Haha... looks like you bought it...

That's a 7 wire unit... so, be sure you look up BassCliff's directions on wiring that in. The 3 yellows go to the stator, and then I believe you have 2 ground wires, and 2 hot-wires... I was sure to get a 6 wire unit... 1 ground, 1 hot, 1 sense (wired to brake switch orange), 3 stator.

Let us know how it works out!

Yeah... I got a little itchy last night and decided to go for it. There was another post on here about R/Rs on ebay that were this model, so I picked it up.

Now comes the wait for parts.... Electrical is about all I can do for now and even then it is just cleaning up the connections. I'm hoping by the end of next week the bike will be running again, depending on how long shipping takes on some parts.

 

[spacepirates]

Question about spark plug wires/caps/boots:

I understand I need resistor caps and solid core wires (to be like stock). Are the boots/caps included in Z1's Dyna Ignition wires resistor caps (http://www.z1enterprises.com/dyna-ignition-wires--7mm-copper-core-red-209.aspx?ID=209)? Should I purchase both those ignition wires and NGK resistor caps? Should I forgo those wires that include boots caps and just get plain ignition wire and the NGK resistor caps?

Or since I'm going to a Dyna-S electrical ignition should I get the suppression ignition wires (http://www.z1enterprises.com/ignition-wire--7mm-black-4374.aspx?ID=4374) and skip getting the caps?

so many options... I can't keep track of them all.

 

[spacepirates]

Question about spark plug wires/caps/boots:

I understand I need resistor caps and solid core wires (to be like stock). Are the boots/caps included in Z1's Dyna Ignition wires resistor caps (http://www.z1enterprises.com/dyna-ignition-wires--7mm-copper-core-red-209.aspx?ID=209)? Should I purchase both those ignition wires and NGK resistor caps? Should I forgo those wires that include boots caps and just get plain ignition wire and the NGK resistor caps?

Or since I'm going to a Dyna-S electrical ignition should I get the suppression ignition wires (http://www.z1enterprises.com/ignition-wire--7mm-black-4374.aspx?ID=4374) and skip getting the caps?

so many options... I can't keep track of them all.

Reposted question and got an answer here: http://www.thegsresources.com/_forum/showthread.php?p=1640536#post1640536

Brake pads, valve shims, and valve gasket came in the mail today. Get to have some fun with those tonight/tomorrow. I'm hoping some other parts show up soon, too! (I'm looking at YOU, dyna-s ignition and coils).

 

[GateKeeper]

Pictures man,,,,Pictures.......

We need pictures......

Can't be doing a build without pictures.....

 

[spacepirates]

Ask and ye shall receive:
https://picasaweb.google.com/112952...authkey=Gv1sRgCM-VuLXg6a-y2wE&feat=directlink

I didn't get any pictures before I took the bike apart. Silly me for getting too excited.

If you have any request for pictures, let me know.

 

[DannyMotor]

So far so good.

 

[spacepirates]

Got the shims in today, installed them and found out that two valves are still too tight! I'm going to pop them out and re-seat them just to be sure before I order more shims.

I also put on the Dyna coils and ignition. The wording in the instructions for the ignition installation is kind of confusing for me when you are setting the timing, but a few posts on this forum helped me clear it up. It wasn't apparent that I needed to turn the advancer with one hand and then set the ignition plate.

Still waiting on mufflers, fuse box, and oil filters. Mufflers will be exciting to see. From what I can tell, there isn't a slip-on joint I can see on the exhaust, so I'll have to cut the old exhaust off after the collectors.

A lot to do...

 

[spacepirates]

Haven't updated in a while, but Old_Skool has been helping me immensely via PM's with R/R and other such nonsense.

I bought an FH011AA R/R off ebay ($50, not bad) and just got that plugged in today. The tank and carbs are off the bike so I can reset the fuel screws and sync the carbs. The VM rebuild tutorial didn't mention how many turns out they should be set, but i've recently discovered this lovely set of information:
GS850 (77-79) the specs are for the VM's
idle r/min........... 950-1150
carb................... mik vm26ss
id no................... 45060
bore size ............ 26 (1.0)
float height ......... 23-25. (0.91" - 0.98")
fuel level ............ 3.0 - 5.0 (0.12" +/-0.20")
pilot air screw ..... 1.25 turns out
pilot screw........... 5/8 turns out
pilot air jet........... 1.2
pilot jet............... #15
cut away............. 1.5
jet needle........... 5DL36-2 (the -2 2nd notch)
needle jet .......... 0 - 6
pilot outlet........... 0.6
by pass ............. 0.8
main jet............. #102.5

I can really only work on the bike for an hour or so here or there if I get home from work before the woman does. Makes it hard to get any big projects done.

The tank was rattle-canned (for now) a deep red Rustoleum paint (really close to stock, actually). I'm trying a Plasticote clear engine enamel to see how it stands up to gas. Not many spray paint cans can claim gas resistance, so we'll see how it goes.

Other than that, Old_Skool was kind enough to sell me a new oil drain pain (mine was stripped out), so that makes it on the list as one of the last things I need to do to the bike. I'm most likely going to try and ride it for a few miles to get some use out of the oil I just put in it (I didn't want the bike to sit without oil for a while) unless it leaks too bad. Right now it leaks a few drops after I park it from running for a few minutes.

Here is a random question:
Can anyone somewhat accurately tell me how freely the front and rear wheel should spin so as not to say any of the brakes are dragging?

The bike seems hard to push around, but it is a behemoth of a bike and it is being compared to the incredibly light Suzuki Savage that is my current daily driver. Once I get the bike out I'll try to ride it only using one brake (front or rear) and touch the rotor of the non-used brake to see if it is hot, but I live in the hills and it isn't easy to get away with that kind of thing.

 

[spacepirates]

Ah, one more thing (there is always one more thing to do, isn't there?) is the exhaust. Mine is rusted through on the mufflers on both sides.

I bought shorty mufflers off part shark and extra fiberglass packing that I'll eventually get around to installing. Hopefully the 850 purists out there won't flip out too much about that, but I need a cheap solution, and cheap means <$50 so saying "buy a MAC" won't cut it.