The rehabilitation of Sir Gustave Sabastian (‘Gus’)

[Box'a'bits]

What’s this thread about:
I’ll use this thread to document my rehab of Gus. Padmei’s doing it, why can’t I? And hopefully we’ll get a community of GS / airhead owners here.

This is what Gus looked like when I bought him in Jul 10.



And the second picture shows what he looked Nov 11.



Why ‘Gus’?
Gus is a bastard in a number of senses. Old vehicles need names. Cursing a thing just doesn’t seem right. It’s always a bitch or bastard. And Gus is positively geriatric.

Why I bought Gus:
I’m a long time airhead fan, having owned a ‘78 R100RS, ‘83 R80ST, ‘86 R65, & an ‘88 R100RS. In the ‘90’s my wife & travelled Europe on the ’78 RS. We spent about 3 yrs alternatively working in London, then travelling the summer months. The trip back home was supposed to be an extended tour through Africa. I actually purchased the ST for that trip, bought a Acerbis 43L plastic tank for it, but alas it was not to be. I wrecked the RS when a van did a u-turn on me, and then the couple we were to go with had a head-on with a minicab. The consolation prize was a trip to the South of France, & then home. Both the RS & the ST were imported back to NZ, but in a moment of madness I sold the ST to allow the purchase of a lounge suite. Which is now almost dead…

I’ve had a couple of goes at getting a GS since, but this hasn’t really worked out. The last white RS was supposed to be one, & the KTM 640a was close (in a sort of ‘Paris Dakar’ way). The KTM was a brilliant bike, but my experience was KTM parts support was lacking. Whilst I am sure the whole package would do big miles, portions of the bike seemed to be higher maintenance then I am used to (Hi ClintNZ & Warewolf!!).

One thing I missed with the KTM was the ability to load either Katherine or Mandy on the back & to go out for a day trip. The KTM was really a one person bike.



Airhead GSs have been on my Trademe favourites list a long time now. I’ve seen a few cheaper GS’s come up (Newguy, Barrie & Padmei). Padmei, you don’t know how lucky you are to have your bike. My finger hovered over the buy now for quite a while the night before you bought it…I have finally decided that I needed to build the bike I had lusted after for 20 yrs.

So where is this heading?
I have agreed with Mandy that I can spend the proceeds of the KTM sale on Gus. Given where the NZD has been against the Euro, GBP & USD I decided to buy some of the larger items now rather than wait. So I have ordered a bunch of parts from Motobins to allow repair of Gus & the RS, Touratech pannier racks & a 43l Tank (I like big tanks & I cannot lie...), to change the handlbars & risers, & have ordered an Ohlins shock from Robert Taylor at CKTechnical. Robert's price has been comparable to import (before freight & GST!), but I get the shock build to my specs.

The wishlist is somewhat more advanced....



To make this thread a bit more manageable I have started & will expand on an index - green text are links. For much of the maintenance & modification I haven't always included links, largely because this happened over a number of posts or pages & may be predominantly text.

Index of Maintenance
- Replacing the carb throttle pivot o'rings
- Replace a spoke in the rear cross lace wheel
- Fork oil replacement (standard forks)
- Discussion of Emulators in standard GS forks
- Replacing a head gasket & replacing the camchain
- Re-ringing Gus, & putting in 9.5:1 Pistons. Part one / Part two

Index of Modifications:
- List of modifications / upgrades to date
- Fitting the HPN Tank
- Nissin 4 Pot Brake Conversion
- Fitting Pivot Pegs
- 48mm KYB fork conversion
- Discussion on replacement sidestands
- Discussion of Emmulators in standard GS forks
- Wiring in resistors to remedy hyperflashing indicators
- Fitting a Baja Designs 8" headlight unit & a Trailtech Vapor Speedo Unit
- Hardhead rocker cover protectors (replace crashbars)
- Modifying the rear brake pedal to improve leverage, & therefore braking capacity

Index of ride reports:
- Cold Kiwi Sep '10 - Central Plateau, Nth Island
- 42nd Traverse, Old Whanga Rd, & Kiwi Rd Nov '10 - King Country, North Island
- Clarence River Reserve Feb '11 here, here, & here. Kaikoura East Coast Sth Island, & Reefton, Sth Island
- Easter Trip Away Apr '11, North Island - Taumaranui, Whangamomona, Taupo, Lake Waikaremoana, Gisborne & back to Wgtn
- Sutherlands Hutt, May '11, associated video clips - South Wairarapa, North Island
- Takapari Rd (Nth of Palmerston North) Jul '11 - Ruahine Ranges, North Manawatu, North Island
- Ocean Beach Ride Aug '11, & ICU breakdown. South Wairarapa, North Island
- Cold Kiwi, Old Whanga Rd, & the 42 Traverse Sept '11 & here. Video of the 42nd rockwall here. Central Plateau & King Country, Nth Isld.
- Odlins Rd diversion. Akatarewas, Nth Island
- Ocean Beach in the Rain - Wairapara Sept 11
- The Ride Of The Steves - Sutherlands Hutt & Ocean Beach, Wairarapa Nov '11
- WAR. Waiouru Adventure Ride, Waiouru Miltary Training Grounds, Dec '11. Day one, day two, & day three
- Ocean Beach 2 up with Mandy Boxing Day
- Ocean Beach with Shewolf NZ, 2nd Jan '12
- Ride into the Mangatooks, Kapiti Coast, 4th Jan '12.
- Dusty Butt Pre Ride - Glendhu & Flat Point, Wairarapa, 15th Jan '12
- Two Fatties & A Skinny Take On Odlins Rd - Akatarewas, 4th Feb '12
- RRRR 2012 (Round Ruahine Range Reversed (Part One) & Part Two - 24th & 25th Mar '12
- Ocean Beach with EddieB - South Wairarapa April '12
- East Cape Airhead Ride, East Cape North Island, 20th - 23rd April '12. Days Three & Four here.
- MMMM 2012, July 2012, East Cape North Island
- MAD (Makairo, Aikitio, Dannevirke) Wairarapa, 30th Sept 2012
- Odlins Rd, Akatarewas, Upper Hutt, North Island. 25th Nov

Other
- What really dumb things have you done in the garage
- Airhead Philosophy

[aslan]

nice post Steve - certainly a fashion among Kiwi ADV members to create their own blogs - a trend started by MarkS and since adopted by Bart & Padmei (there may be others) - good on ya anyway - looks like the restoration of your R100GS will be an interesting and hopefully rewarding project - have fun Cheers Aslan

[Box'a'bits]

Gus's History:
I purchased Gus from Rob in Whangamomana. Gus has done some miles - 198k kms (or 124k miles). First registered in 1991, & owned by BMW as a demo, then through two Rental Cos. Then 3 private owners: a father & son; then Rob. In the two years of Rental Co ownership, they racked up 160k, which I take to be a good thing. Hopefully long miles, & regular servicing. Maybe mature renters.

Initial Impressions
Looks-wise, Gus is almost a twin of Padmei’s R80GS, but is the R100 variant. Given the mileage there is some damage, but nothing that time, patience & money can’t fix.

Rob used the bike for adventure riding, and had a heavy fall on the right side at some point. He’s repainted the crash bars, but not the right rocker box cover, which is very battle scarred. He demolished the screen too. There is a dent in the right top of the tank, which might pop out with a bit of air pressure. He had made an engine bashplate, a new screen (clear Perspex, well shaped), & also a new stainless collector box (now well dented – no rear bashplate). He’s replaced the alternator rotor & the timing chain. No other history provided.

I have ridden him a grand total of about 100 meters, from Rob’s garage to the trailer, & from my trailer into my garage.

The shock seems ‘tired’. There is some rust starting on the left fork leg, between the triple clamps. The neutral light doesn’t work. The oil pressure switch seems like it has a seep. Oil weep near the sump gasket. The rear light has been broken & glued. The rear indicators have been replaced with smaller variants. The rear subframe paint has suffered from Rob’s top box (removed at sale). The swingarm / frame boot is perished.

The motor (on start up) was one of the quietest I have ever encountered (but an indication of valve lash being too tight). Idle was smooth. No noticeable issues with the driveshaft or gearbox. Tank shows some overspray. Repainted crashbars already mentioned. Tyres looks good in the Trademe pictures, but are actually munted. Rob sure enjoyed those corners round Whanga…

First job – valves
Intially I was really pleased with the color of the left plug. But the right side wasn't as good, & investigation showed the left carb to head rubber wasn't done up - so the jug was lean as a result of the air leak. Things that make you go 'Hmmmm'.



Adjusting valves are really a piece of cake BUT… someone has been over enthusiastic with the locknut on the left side. I’ll replace. Also the rocker cover central stud. I see this has already been helicoiled once. Also while I’m down there someone has bent the fins on the exhaust nuts trying to get the nuts off. I’ll need to replace that.



The Exhaust Nut doesn't look too bad in this photo, but that's because I've already managed to roll it 45 degrees. Believe me, its very sad. To the extent that the exhaust nut spanner doesn't fit anymore. Butchery

Endurolast Alternator
I bought this for the RS because I got tired of the limitations of the stock system. Here's a link to the Enduralast site.



On the stock system, I'm up to my third rotor, & second diode board replacement. I’d upgraded the mechanical regulator in London to deal with a commute I was doing, & had also upgraded the wiring.

I’ve now swapped the Enduralast across to the Gus. The stock system will go on the RS.

Starter Motor:
Valeo starter motors have a reputation for the magnets becoming un-glued. Also, sometimes they become noisy when they don't disengage immediately from the flywheel. I already had the starter motor out, so I decided to pull it apart to clean it up as much as possible. There is a lot of good info at Joergs website & also Anton Largiarder's. Stephen Bottcher actually epoxied between his magnets, so that if the glue on one failed, it would be held in by the others.

The 1st photo shows the top of the starter motor off. The 2nd has the actual motor detached, & the solenoid not yet disassembled. Basically I just cleaned & reassembled.



Unfortunately when I bolted the starter on the block, I managed to drop a nut down into the flywheel area (it was already in a socket I was about to use - who put that there?...). Oh well, I needed to do the clutch splines anyway!!. And the neutral switch isn't working, and the easiest way to fix it is to drop the gearbox..

[bart-nz]

Nice work Steve. I'll be watching with interest, as I'd like a project like that. It might be a decade before I get the time/cash though.

Off topic, but was that you who out bid me for that DR rear sprocket today Aslan?

[Padmei]

Good stuff Steve. Yay now I can compare notes.
What are the limitations you talk of with the stock alternator setup? Output not enough to handle running a few appliances or parts just don't last long?

Have you got any pics of the top of your bike with tank & seat off? Just want to compare.

[Dino3310]

Very cool mate, will be watching with interest

[Box'a'bits]

Originally Posted by Padmei

What are the limitations you talk of with the stock alternator setup? Output not enough to handle running a few appliances or parts just don't last long?

Photo of the top of the bike as requested. Looks just like yours, down to the manky wiring. But the variances are for the Enduralast Alternator


The stock alternator output is 280w at best, but can deteriorate if the wiring / connections are allowed to corrode. The alternator takes to about 3k (?) revs before it actually even covers the engine & light load. This is problematic if you are in slow going or commuting. It relies on the red dash light to excite the charge circuit. If that fails, no charge. The diode board is in very hot / hostile environment - not the best for reliability. Stock grounding for the diode board is not great. A common fix is to run a ground wire from the front cover to a ground on the block.

BTW don't ever take the front cover off without disconnecting the battery ground - easy to burn out a diode from static charge if the cover scraps the diode board. DAMHIK.

There are work arounds for all of those issues.

The Enduralast not only makes more charge, it also starts charging earlier than the stock system. It's also a brushless unit (constant magnet), so potentially maintenance free. Have a look at the site, all will come clear.

My understanding are that the major differences between the two bikes ex factory are the carbs (you've 32mm, I've got 40mms), barrels & heads, & the final drive ratio (yours is a little shorter). That's pretty much it.

[NordieBoy]

Originally Posted by Mark_S

we do have minimum standards you know

Ok. Put on a loud pipe then...

[Box'a'bits]

Rainy day, I'm going out to the garage for some play time. Need to install these & also paint the Gilera forks, & change the fork seals & oils.

I got caught out with the spoke & nipple purchase. Some shops include the grub screw. Boxer Supplies didn't. I bought new nipple heads in anticipation of issues removing the old ones.



First up the gearbox oil sight glass. Really just a bit of bling, but lets me keep an eye on the level & color of the g/box oil.



Replaced the stock paper air filter with a foam Uni Filter. I was a bit surprised when I took off the paper filter to find water in the filter housing. I assume this is from a poor seal on the paper filter, maybe from when I took the tank off to wash the bike.

The Uni Filter allows me to clean it more regularly, and also offers some mitigant in case I drown the bike. A soggy paper filter would be the pits. Hopefully this won't require a rejet, as I've just got the carbs sorted.



I also replaced the bent spoke. This was fairly easy. Soaked the nipple ends in WD40 for a while, to allow them to break any hold corrosion had on them, and to allow them to move more freely. Went to remove the grub screw (2mm allen key req'd) in the hub nipple (which uses a 5mm), and it actually moved the whole nipple. With that out, cut the spoke to make it easier to remove. Deflated the tyre to give me room to remove it. Put a tyre iron between the tyre & rim to push the tyre wall back, to allow the spoke to come out cleanly, then drifted it out.



Cleaned out the spoke head seating area on the rim, and also the nipple area on the hub. Used a bit of moly grease to ease the seating & stop corrosion.

Tightened the spoke from the hub end. Used a punch to ensure the spoke head end in the rim was seated well. When I was satisfied the 'pitch' of the tensioned spoke was the same as others running the same way, I put in grub screw back in & tightened this up. All done.



I re-used the spoke nipple & grub screw. The stainless ones I bought would have stood out. Also they use Torx fittings, which I have, but I didn't want just one on the wheel.

I note that the spoke tensions on the wheel are all over the place. Sometime soon I need to go back & retension the lot to similar pitches.

Mark_S, just so that I'm not mucking you around, definitely cannot make the MMMM ride this year. Had to make some rash promises to placate Mandy when the above arrived from the Netherlands..... Apart from that work & finances just don't really allow.

[Padmei]

Nice .
Ireplaced my old unifilter with a paper one. The gearbox oil sight glass is a great idea - I'll have to put that one on the wishlist.

I still can't see why I couldn't replace all the spokes one by one like you did with your bad spoke. Might be time consuming however you'd keep the runouts within cooee I reckon...

[Box'a'bits]

Originally Posted by Padmei

I still can't see why I couldn't replace all the spokes one by one like you did with your bad spoke. Might be time consuming however you'd keep the runouts within cooee I reckon...

From what I can gather, wheel builders won't touch 'tweaked' ones, because you can't use the spokes to correct the run out like more traditional rims.

If you start with a straight rim, I can't really see what the issue would be? The tubeless rims are very strong (& heavy).

Certainly the dealers are selling the stainless spokes somewhere.

Re the sight glass, remember that you fill to the bottom threads of the filler hole. So technically you won't see oil in the glass unless you tip the bike slightly off vertical. But easier to check than taking that plug out. There are a couple of versions. I've just got the sight glass one. There is also a filler one. I didn't get that because I figured that'd end up getting fouled with my boots.

[Box'a'bits]

Seven of us started from Mana (Stephen, Neville, Bruce, Howie, Ian, ?), picked up Mark S at Shannon. Robin & 86GSX at Ashhurst. Graham Flyger also rode up but didn't accompany us.

Looks like the Manawatu almost had a frost. It was cold. And the weather didn't cooperate & clagged in. Aslan took us for a bit of a magical mystery tour of the upper Pohangina Valley, but it was a bloody good gravel road, so who the hell cares.



Lost Robin at the bottom of Takapari Rd. He deicided not to go up with us, given he was running a road oriented front tyre.
Takapari Rd was clouded in, which meant we got wet on the way, & didn't get the views, but hey, its an excellent ride. There was snow clumps nr the summit. We all stopped at the A-Frame for a warm up & pictures. Did anyone get a pictuire of the snowman on the way back?



The group split into two, 4 going back, but Ian, Stephen, Mark & I decided to get to the end of the road. The road deteriorated markedly after the A-Frame Hut, with large erosion washouts & some sections with large rock loose. We stopped when the road did - there was tracks going into a bog. I wasn't successful in getting Mark S to 'test the water' for us.



Coming back was even more fraught than going. Is that clutch I smell?









Back down, someone needed a tow to the gas station, & then the fab four headed off to Ballance for a coffee & lunch. Attacked North Range Rd, the Lower Class Road attracted the riff raff, & we proved it isn't a dead end. Also fairly sure the 'temporary' 20km warning sign has been there a while - its growing moss. One dab in the middle of a huge mud puddle on the way thru, when the front washed out. Fortunately that was sufficient.

Home by dark, bloody cold.

[Mark_S]

Only half decent photo I took of you struggling up that snotty steep climb

was a great day :)

[aslan]

Great pics and report Steve - gotta confess to the others reading this it was me who needed the tow to the gas station - new pipe on the DR sounded great - bottom end performance felt more responsive - fuel economy took a massive hit - thanks for your company BMWRSNUT & Mark_S

[Box'a'bits]

Started working on a number small items that need attention. One was to replace the value adjuster screw & locknut. On the left inlet, some heavy handed clutz had damaged the thread, which made setting the clearance difficult.

First dropped out the sparkplugs. Showing a nice tan colour, but some carbon, and maybe blistering? I haven't checked these for a while. The right side looks slightly better.



Checked the valve clearances. Still all good. Then backed off the adjustment, given I was going to release tension on the four head studs. Left the top & bottom nuts as is - they hold the barrel to the head.



Backed off all four head studs (but not completely), then released the two the hold the inlet rocker, so I could lift the rocker away from the bike. Disassembled the rocker, then covered over the internal rocker needle bearings with a paper towel to protect them from the next step. Used an angle grinder cutting blade to take off the damaged portion of the adjuster bolt. I had tried to just unwind this, but the thread damage was too great, & would have damaged the rocker.



Then reassembled, remembering to have the mark on the rocker shaft pointing up & outward, so that the oiling galleries were correct. Tightened the nuts on the head studs in a criss-cross pattern, initially at 10, then 15, 20 & 24 ft/pds. Readjusted the value cleareances, rotated the engine, checked again & readjusted, job done.

Back to cleaning, sanding, priming & painting (rocker box covers, gearshift linkage, front wheel spindle washer etc). I assume someone has used an acid wash on the bike at some stage to bring the alloy up - which has susequently attacked the other metals.