Re-awakening '79 R100RT

[Rick Phillips]

After many years of slumbering my '79 R100RT needs to be re-awakened.

I got it when I was stationed in Germany in 1979 when it had only 1,500 miles. I rode throughout Germany, to Luxemburg,Netherlands, Belgium, England and Ireland. Before leaving Germany I sold my car and the bike was my only transportation for the following 18 months.

Over time I rode less and less to the point I've not ridden in five or six years. Now I'm retired and want to start riding again.

I'm seeking advice on what I should check to make sure the bike's in good working order before riding. It's been garage kept the entire time, but I did not take any special steps for storage.

TIA,

Rick

 

[88bmwjeff]

There will be plenty of people here that will give you their $0.02. I would do a search on the board here, since this topic has been discussed before. Also, look at some of the bikes that were resurrected, and the problems they faced.

And, welcome to community.

 

[rozemab]

Rick,

Welcome to the forum.

As a minimum I would change all fluids, filters and plugs. Pull the tank and clean out the inside. Inspect the master brake underneath the tank since those tend to leak over time. I have upgraded mine to the handlebar.

Pull the carbs and clean all ports/circuits with carb cleaner and compressed air. Remember to remove any rubber or plastic parts if you soak them in cleaner.

Replace all gas lines. Install an inline gas filter below the petcocks.

Inspect the bellows (drive shaft) for dry rot.

Has the input shaft splines been lubed lately? If not, it is worth your time to do it (or have someone do it for you.)

I don't know how mechanical inclined you are but make sure you understand how to change the filter (oil) correctly. Don't be afraid to ask if you don't understand what I mean.



Spare parts can be found through your local dealer. See the posting on several sources for parts and those dealers that offer a GREAT deal (20% off list for the exact BMW part).

Patience and taking your time is key. You should NEVER have to force a part to fit. If you decide to tackle some of the major maintenance items (spline lube) make sure you take pictures (go buy a cheap $50 digital camera) to help remind you how things go back together.

Some maintenance items require special tools (not expensive) to complete.

Brian

 

[jischr]

My 83 100RT had been sitting around for 7 years when I bought it. To get it home we jump started the battery, checked the oil level, drained the carbs, and topped the gas tank to dilute the old stuff. Over the next few months I replaced the battery, rebuilt the brakes on both wheels, replaced the tires, the clutch cable, and the LBS that changed the tires put 10 pounds of lube on the spline. I used the polishing kit that 3M sells to remove the yellow on the wind screen. That was two years ago and I haven't done much since. I've adjusted the valves a couple times, changed the oil, and dripped a light oil down the throttle cable when it got hard to use. I may be living on borrowed time but it seems to be running well and I don't have money for maintenance anyway.

Good luck with yours.

 

[manicmechanic]

You might reconsider putting any kind of oil-based lube on your cables. BMW usually has cables that are teflon-lined, and oil can make the lining swell and stick. As far as the rest of the reawakening process, fuel system, check for blockage in the exhaust, battery conditon, oil change, brake fluid change, tire condition. Once you get it running and deemed OK, then a short ride to look for leaks to develop. Go from there.

 

[kstoo]

+1 on the preceeding...
Also, if those tires have been sitting for 5 or 6 years it is time for some fresh road holders.
I have heard of several instances lately (one was a 1979 R100RT that I got to part out after the accident) of front brakes locking up after being pulled out of retirement. On the RT mentioned above the rubber brake lines to the calipers had swollen shut like arterial sclerosis. On others the brake fluid held so much moisture and corrosion that the brake fluid would 'boil', expand and lock up the brakes. At least flush out the brake fluid. At best, replace the lines and inspect the caliper pistons.
When you change all fluids that includes the black swamp smelling stuff that will be in your fork legs.
If your steering feels funny it may be that the steering stem bearing grease has dried up.
Remove the rodent nests from the air cleaner housing.
Ah .. good times ...

 

[Rick Phillips]

Thanks for all the suggestions. I expected to change out all the fluids, lubes and as much rubber as possible.

Should I have any concerns about valve springs, piston rings or piston walls?

Also, what's the current thoughts on unleaded gas and valve seats. The bike has the original valves and valve seats. I read Snowbum's article about avgas ( www.bmwmotorcycletech.info ) and found it interesting but would like to get other points of view.

 

[rozemab]

Rick,

I don't know if the bike sat without starting for years. I would pull the plugs and squirt oil into both cylinders and try to crank over the engine.

A good bet is the battery is shot. Go for a sealed version as they are technically superior to flooded batteries.

Take off the tank and seat inspect ALL connections for corrosion and broken or frayed wires. Don't want to read about a toasted beemer anytime soon.

+1 on inspecting the air filter housing. A friend of mine had about 1 lb of Purina Dog food in his filter :O .

 

[ISAMEMON]

DONT SELL THAT BIKE

I know you did not say you were, but many of us would love to be the original owner and have such a history.

Other than that, info has been good so far
imho, I would plan on flushing fluids, its just my way, I would not go hog wild on great fluids, I would drain, put in some oils, fire it up, run it through the gears, heat it up, drain, and then good stuff. You can even do it on the center stand,

as far as the carbs, I have read great stuff on adv forum, about people just soaking carbs in pine-sol. it eats greese and gunk , and wont eat the rubber parts. however I have not tried it myself

as far as rings etc, has it been sitting for years without even being turned over ?

there is debate at times, but I would definately shoot some light weight oil into the jugs, and crank it , wiht the plugs out.. ON a more upright engine, I shoot in atf, and let it soak in the cylinders, for a while, then crank, with plugs out, I have even brought back to life frozen engines that way. but on these horizontal engines, you would have to put in way too much fluid into the jugs

if your not familiar with adv forum, go to the link, enter, and go to "olds cool", its about old bikes like these and youll find many of the same people that are on this forum over there too

http://www.advrider.com/

 

[James.A]

Being a long time owner of 70's airheads, I don't think you will need to worry about your valve seats for a very long time. Valve recession is starts to make trouble at around 40,000 miles and is unsustainable at around 60 to 70 thousand miles in my experience.

Now then, if your bike is in the 70,000 mile range, I'd still get it running and campaign it a bit before worrying too much about the un-leaded gas issue.

Right now, I am rehabilitating a 1978 R100/7 with at least 150,000 miles on it. Even at that range, I will for sure run it a year and then make decisions about what it really needs. I am confident that it has AT LEAST another 50,000 miles in it, probably much more.

 

[crazydrummerdude]

Where are you located? Some of us like lending a hand.

 

[Rick Phillips]

Where are you located? Some of us like lending a hand.

I split my time between Atlanta and the mountains of North GA. The bike is kept indoors in North GA. Most of the work will be done there.

 

[Rick Phillips]

DONT SELL THAT BIKE

as far as rings etc, has it been sitting for years without even being turned over ?
there is debate at times, but I would definately shoot some light weight oil into the jugs, and crank it , wiht the plugs out.. ON a more upright engine, I shoot in atf, and let it soak in the cylinders, for a while, then crank, with plugs out, I have even brought back to life frozen engines that way. but on these horizontal engines, you would have to put in way too much fluid into the jugs

if your not familiar with adv forum, go to the link, enter, and go to "olds cool", its about old bikes like these and youll find many of the same people that are on this forum over there too

http://www.advrider.com/

Thanks for the info Isamemon.

Yes, it did sit for several years without being turned over; that's the reason for my concern with valve springs, rings and cylinder walls.

I'll check out advrider.com

 

[dennisdarrow]

NW Georgia here and more than willing to lend a hand........

+1 on: new battery, flushing the tank, draining the float bowls, fresh motor oil and fuel, pull the plugs and put in a bit of oil, crank it over a bunch, check for spark at each plug, reinstall plugs, and fire that puppy up.........Perhaps make sure you do not do the start up in a closed area. IT IS GONNA SMOKE A LOT.........

NEW tires, TOTAL 10K service, and then RIDE............God bless.......Dennis

 

[AnnapolisAirhead]

I split my time between Atlanta and the mountains of North GA. The bike is kept indoors in North GA. Most of the work will be done there.

Welcome to the forum Rick! Sounds like you have a keeper with a great history. I just relocated to Atlanta, have lots of tools, extra parts, a bike lift and happy to help (ride, wrench, chat). Got my start by resurrecting a '76 R90/6 and an '83 R100 that I converted into an RT as my daily ride. Both sat for 8 or 9 years buried in a garage, so maybe I can share some of my lessons learned in the school of hard knocks. You may also want to plug into the Georgia Airheads (www.airheads.org) as well. Great source of knowledge there.

I'm near the Mall of Georgia and commute to Windward. Drop me a PM if you need a hand.

 

[lkchris]

A good bet is the battery is shot. Go for a sealed version as they are technically superior to flooded batteries.

Except unless you have a G/S, ST or a short-wheelbase /5, none are made for Airheads.

A battery that requires modifications to the bike is NOT a battery made for an Airhead. That is, there aren't any sealed batteries made for a '79 RT. The flooded batteries still available are just fine and will last a long time if properly maintained.

 

[crazydrummerdude]

A sealed WestCo fits just fine (no modifications) in my battery tray.