Back on an Airhead - 1975 BMW R90/6

[beachmike1]

Gas tank drain..derust. Clean. Rinse. Treat with naval jelly. Rinse.

Clean peacocks..replace seals and and o rings. Check
Replace fuel lines.
Replace plug wires.
Rest timing
Clean recap plugs...put a nice shot of penetrating oil in cylinders. Let air out then a shot of 30 wt
Drain oil which is 12 years is crud.
Refill with new oil.
Fee stuck clutch.
Install new battery.

Clean water contacts you can get to.

Replace tires..after 12 years they are junk...period tires have a lot of oil and other softeners I. Them that leave the system over time. Also with high ambient temperatures the elastomeric cross linking continues to take place. These two factors will remove grip to the point of a hock puck.

Replace the tubes too.
Grease the steering head and wheel bearings. Prop shaft and change rear gear ol. Lube all control Cale's. Change brake fluid and lube rear drum pivots in the hub.. Replace the rubber grommets in the shocks. Fork oils should be replaced.

All fluids have a probe. The diurnal temperature differential pumps cool air in at nigh ..with moisture and hot air out during the day..any moisture will eventually hit the dew temp and settle not the guild and contaminate it...lighter fractions of the lube will evaporate. Leaving watery yucky stuff that is lousy for ube and
Okay to drink.

All lubricants age and collect dust.

Whine this is done. Put in good gas with preservative and all that crack with fuel off.and battery on a trickle charger.
Listen for starter speed. It should not start as the plus are not in..you are luring the bottom end with no load. So this in 30 sec pulses for five min over one hour... The add plugs ..attaché leads turn on gas. Remove air filter. Use a squirt of starter fluid and start. Have a wet rag ready I case of fire. It sould start and run for a few seconds racing then runn regularly..there will be smoke.

Oh clean out the exhaust before you start the bike. Critters live in those.


Kaynthat was some money. But grease drips out ages and stops lubrcitabg

[tete]

This is exactly what I needed. I've been putting together a hit list of things I wanted to do. I think you just about covered it and then some. I'm starting to believe the PO actually filled it with fresh oil when he stored it. i will replace, fuel lines, inline filters, rebuild petcock, battery of course. The tank is surprisingly clean but will get a cleaning as well. all the proper end will get their attention in due time. I'm focused on making sure it can start/ run OK before I start dumping an extraordinary amount of money into it. Once I feel confident about that I will purchase tires etc.. plugs, rebuild kits, hoses and filters, oil can all be recouped in the event I have to part the bike out.

I'm pretty confident this bike was stored properly. There is ZERO rust. And the oil was fresh. I was told that storing bikes with fresh oil is the way to do it properly. The PO was a bike mechanic I found out. had a complete garage and such but worked on this and his .............harley..... might explain the chrome. You woul dhave thought he would have drained the gas tho

I guess we will see.

[disston]

I don't think I would replace plug wires unless they were out of spec. Measure with an Ohm meter. I don't think I would treat a tank interior with Naval Jelly unless I was going to line it with a liner, then the liner kits come with the stripper you need. But you are just tryin to get this bike fired up I think? This idea that people have about restoring a bike coming out of storage, just so they can hit the key and ride around the block, I don't get it. There are things to do but you are first just trying to get the thing running, and ride around the block. After that you will know more about what the bike needs.

Any where there is grease you should clean and regrease. Check preload. If the bearings look OK then they are OK.

Clean the tank with a garden hose, water. Get any and all crud out of the tank. If there is evidence of there had been a lot of flaking or rust passing thru the petcocks you may want to rebuild these otherwise you may decide to go with them if they flow well. Dry the tank with compressed air if you have it, otherwise make sure it is set in the sun and thourolly dry before reusing. I am talking about a basically sound tank. If you have Severe Rust or Pin Holes in the metal we will have to take more extreme measures.

Sometimes you will want to rebuild the carbs or you may decide that a cleaning is all that's needed right away. If the carbs sat with fuel in the bowls they will have a lot of crud in the bowls. But you may get the upper passeges clear with a hundred pounds of air and some B-12 carb cleaner.

Floats, float needles and diaphragms are critical at this stage.

Replace the fuel line. If you want the fuel line filters get the plastic ones that you can see through. If they aren't readily available then run it with out filters.

If the tires hold air they are good enough to ride around the block. You are not going above 30 mph, maybe. You are going to get tires in the next phase but they can wait till you get it running.

You are going to have to check the points and the timing. You should order a set of points and a condenser but may not need them to start the bike. Look at the points in place now. If they transfer of metal from one tip to the other is very much then go ahead and replace them. I would know what this is but it is hard to describe. If unsure, replace the points.

Set the valves.

You will want a new pair of spark plugs. Again use them if the ones there are in question.

Get a new air filter. Replace that. It's hard to see the dirt in an airhead filter.

Change the oils, all the oils and the filters. I even want you to change the fork oil but if you put that one off it's OK.

I have really bad news for you. I would have had this bike running in two days, three at the max.

[tete]

Is there a way to check if the starter is bad?

[disston]

Starter load testing is a little beyond the ability of most home garage mechanics. If the starter is out you can hook it up and watch it spin. An indication it is good and the amount of "kick" might give you some bit of confidence but the real test is a fresh battery and see how it cranks.

With the plugs out of the bike, make sure the plug wires are grounded. A good starter should spin up pretty fast.

[tete]

A few things I have picked up.

Carb rebuild kit,
Spark plugs,
oilfilter
drain plug crush washer
oil filter gasket
fuel line,
fuel filter
petcock washers
clamps
spark plugs

tomorrow I'll pick up a battery

BMW OEM want like 140$ or something. any lesser cost recommends that I can find locally at an parts store?

At 140$ couldn't I just find a gel or optima battery and be done with it all?

This week end I plan on knocking this stuff out and hopefully starting her up. at worse find out what the electrical issue might be.

Tank is in excellent condition with NO RUST. My plan is to clean it as good as possible and let it air dry. re-install petcocks. rebuild carbs, install new fuel lines/ filters, clean air filter, new plugs, oil and filter. Im sure im still forgetting few things. whatever the case, you get the idea.

[Biebs]

Batteries Plus - in AZ

Odessey PC680 battery - takes 1/2 the space as stock fits very easy. Seat cover available on Ebay $59 made to fit stock seat.


I had the PC680 in my 74 R75/6 4years + never charge works great fits without messing with the subframe terminals match up.

Also check mottard-eletric new wires for battery+ and _ plus the beacon 1 LED brake light kit. All money welll spent.


http://www.motoelekt.com/lighting.htm

[disston]

Nice list of parts.

Here's the battery to get. Small so you have to shim it but that's not a big deal. It's an AGM, sealed, and they are Lead Acid so they don't die all of a sudden like some other new technologies.

http://www.batteryplex.com/toyo.cfm/m/6FM18

[Biebs]

Originally Posted by disston

Nice list of parts.

Here's the battery to get. Small so you have to shim it but that's not a big deal. It's an AGM, sealed, and they are Lead Acid so they don't die all of a sudden like some other new technologies.

http://www.batteryplex.com/toyo.cfm/m/6FM18

Battery $44.95 good deal but reccommended charger $109 so $150 plus you will need a new battery in 2 years.

Odessey PC680 Get it!!!!!!!

[wirewrkr]

Originally Posted by Biebs

Battery $44.95 good deal but reccommended charger $109 so $150 plus you will need a new battery in 2 years.

Odessey PC680 Get it!!!!!!!

What, are you a dealer for Odyssey or something?
You can use a battery tender, and it lasts Waaaay longer than 2 years.
Get some more experience under your belt before making a silly statement like that.

[tete]

Originally Posted by disston

Nice list of parts.

Here's the battery to get. Small so you have to shim it but that's not a big deal. It's an AGM, sealed, and they are Lead Acid so they don't die all of a sudden like some other new technologies.

http://www.batteryplex.com/toyo.cfm/m/6FM18

Can I use a regular tender with it or you are pretty much stuck with a $100 charger?

[Biebs]

Originally Posted by wirewrkr

What, are you a dealer for Odyssey or something?
You can use a battery tender, and it lasts Waaaay longer than 2 years.
Get some more experience under your belt before making a silly statement like that.

Just years of experience with motorcycles, Cars and Batteries that start them.

Trying to help someone out from having to buy a new battery every season. You can always go to Walmart and get a battery for $44.95 but I feel the PC680 is a wothwhile investment. I have a 1974 R75/6 4+ years on current PC680 I am sold - trying to help a fellow out with good advice. Had the same in my 1981 R65 worked great until it was sold.
My 1989 R100GS - had a westco battery when I bought it - replace with a battery from Batties + (not PC680) had to replace in less than a year got a free replacement not a PC680 but it will fit and will be my next battery for the GS. So lots of experience just good advice!!


TETE - you can use a regular battery charger with that battery - if you ride at least 1 once a week 15 or more miles you should never need a tender.
If you do need a tender than something is wrong with your charging system of you have to much load on it. Easy to check with bike running check with volt meter across battery terminals should be above 12.5 up to 14 volts depending on engine RPMs.

[tete]

I think I'll take the Toyo battery as I need to save money where I can. It looks like many have been successful with it here. I'll pick up the battery, a tender and buy a seat off another member for the price of just the oddessy. I admit. i have heard from many, when you want the best, buy the oddessy. I can accept something pretty close at less than 1/3 the price. I appreciate all the input. The tender will be needed as the summer here in AZ can bring difficult times. I plan on riding the bike 4-5 days a week. All my previous bikes I road more than I drove.

Unfortunately that means I will have to wait till next week to probably start the bike because the shipping time for the battery. Thats fine as I have many things to order. I have decided that im in the bike for the long haul. If I get in there and need a complete rebuild then so be it. Thats another reason I am wanting to save money. In the event that is the case.
(from the looks of it mechanically I am confident) the PO son said the problem with the bike, to his re-collection, are all electrical. Alternator / Starter / something on that level.

I am impressed on how many people on here know so much. Not only that many offer products that will help my bike run better, smoother and look the part. I plan on paying you guys back by supporting your products. I appreciate all the help.

I've decided to go with the R90/7 tank I have and a seat from another member on here. I also plan on having a custom seat made. One for travel and one for kicking around town. I'm really liking something on this level but funds will determine he end result. obviously the bike has some features I could never match.

http://www.returnofthecaferacers.com...aquerelle.html

[disston]

Everybody is hooking their batteries up to these trickle chargers and leaving them. That is not the same thing as charging the battery once in awhile. If you ride once a week you don't have to charge a battery. If the battery gets a little low a battery charger hooked up for an hour or two will charge it. It doesn't have to be plugged in 365/24 which is what people want the little chargers for.

I think Wirewrkr has 6 years currently on a Toyo battery? Or was it 5?

[rufusswan]

He said 6 yrs. I've had mine going on 4 years. Seems like a rock solid little battery. Never had to use the charger on it, though sometimes I park it in the house for a month or two if it's winter.