Technical advice

[schrader7032]

Have you done the compression test yourself? I suspect it was done correctly, but in order to get a correct reading, it should be done on a warm engine and the carbs should either be removed or the slides held open to allow air to flow freely.

Another diagnostic test that should be done is a leak down test. This will tell you specifically where the problem is. Likely it's still the rings, but you'll know for sure.

A bike with unknown provenance should really go through a good mechanical restoration. After you have the results of a leak down test, you'll know what to attack. That would mean measuring the ring gaps as well as the ovality of the cylinders. You may have to go to 1st oversize to get the back back to proper health. While the heads are off, probably a good time to look at the valves, seats, and guides.

Slingers are the big unknown and the only way to feel confident in your ride is to have it torn down completely. Then you'll know that the bike is good in that area for another 30 to 50K miles depending on use and care.

The only way this can be cheaper is for you to do all the work yourself. You'll need some special tools, which are available. And you'll need to have good mechanical skills and know how to read the inside of the engine in terms of bearings and crank journals. You can also use Vech at Bench Mark Works to provide insight, parts, and overhaul services. He's at http://www.benchmarkworks.com.

These bikes are hobbies...expect to put some money in and some of your time. But they can be fun!

Kurt in S.A.

[Allan.Atherton]

... my new BMW is a bit of a stinker. R60US bought from the internet and delivered cross-country. The seller hadn't mentioned really low compression... A friend advises me to pull motor, clean the slingers and replace everything....is there an easier (ie. cheaper$) solution? ...
Been there:
http://home.insightbb.com/~aatherton/R60-2/R60-2.html

You sort of have a tiger by the tail. The cheapest solution is to pass the bike on to another owner, taking a small loss. If the compression must be improved to sell it, order new rings to fit the piston measurements, hone the cylinders and install the new rings. There is a good chance that will help the compression.

If you want a reliable bike to keep a long time, you need to have the mechanicals all inspected and rebuilt as needed, and while that is being done, you may also want to do a cosmetic restoration.

Mechanical rebuild includes forks, engine, transmission, wheel/swingarm bearings, and advance and coil and speedo. Cosmetics include spokes and rims, paint, wiring, and chrome and rubber parts.

Five years ago we had the 5-5-5 rule. A running bike was $5K, mechanical rebuild was $5K, and cosmetic restoration was $5K. Those costs have gone up since then. Parts and labor are up, and increasingly there are bad surprises.

A few years ago, a friend in a distant state bought a nice-looking and fair-running R60US for $3K, put $2K into it for accessories and maintenance at his local biker shop at which point they said they could not fix the stripped header nuts and don't bring it back. He asked me what to do and I gave him the same answer as here. He decided on a professional 100% restoration with some upgrades. In addition to the usual work, the heads needed aluminum restoration, the crank needed rebuilding, forks were bent, timing gears mismatched, one control was ruined by JBWelding onto the handlebar, and a 12V EI was installed. The restoration totaled $18K.

If you restore the bike and sell it after a few years, your loss will be much greater than if you can sell it now. The two bikes I restored in 2000-2001 and kept for 6-7 years each sold for $5K less than invested.

If you don't restore it and do the minimum to keep it, the bike will likely always be causing trouble and inconvenience, and you could eventually incur almost as much cost as proper complete mechanical rebuild.

[johnnytodd]

Ok, Ok, I get the message: pass it off to someone else

[johnnytodd]

on second thought, I'll try my hand at the repairs.

[Bruce Frey]

We feel your pain and anguish!

I think I would be inclined to confirm the compression check (with leakdown, if possible) and open up the offending cylinder. It is not too hard to do. With some luck, it may not be too bad and you can have a riding machine that you can enjoy while deciding if you want to commit to a major overhaul or renovation.

A restoration project can turn into black hole as previously mentioned.

Bruce

[schrader7032]

on second thought, I'll try my hand at the repairs.

...or try a combination of repair options. That's what I did. I felt comfortable with the top-end teardown and removal of the engine electrics. I pulled the tranny and clutch parts out. I took the remaining engine block to my mechanic and had him go from there. I also took the heads and cylinders so he could evaluate them. I ended up leaving the heads with him to have the valves/sets/quides replaced.

It gives you a chance to get dirty and become familiar with the machine as well. If you're lucky, like I was, the mechanic let me kibbitz from the back row and take pictures. Should save some money unless he has that sign in the shop - "$70 an hour shop rate; $100 if you help"!!

Kurt in S.A.

[pierce7221]

seconding the slingers. i know it's a lot of work, but i bought a bike with an unknown history and did that job on it myself. i'm glad i did because the slingers were overfull with crap and it was migrating down the tubes and into the bearings. i'm not sure they had ever been cleaned. so that would have destroyed the crankshaft eventually. surely not a part you want to replace.

[johnnytodd]

I've taken the advice of members and torn into my R60 motor with the goal of cleaning the slingers and checking the bearings.

Can anyone tell me what oversize ( if any) my pistons are: the number on each piston face is 72 45

Thanks, John

[schrader7032]

Standard size is 72mm. Your pistons are 1st oversize.

Kurt in S.A.

[VBMWMO]

My first post. Sadly my new BMW is a bit of a stinker. R60US bought from the internet and delivered cross-country. The seller hadn't mentioned really low compression on one side (60psi x 120psi). Valves are adjusted; adding oil to the low cyllinder raises the compression = bad rings? A friend advises me to pull motor, clean the slingers and replace everything....is there an easier (ie. cheaper$) solution? What should I do?

johnnytodd