[klemkas]

I have one more headache. Previous owner "painted" the engine black. I want to restore the original color and get rid of this crap. It looks like original paint also started cracking. But i don't know what to do about it. Asked in the local motorcycle forum, but no one answered. I'll try googling more about it later. There should be some "diy at home" solution..

 

[hubbaloo]

Klemkas, I don't know how prices compare but have a look at these UK based sites for a guide.

http://www.motorworks.co.uk/vlive/Shop/Parts.php?T=5&NU=15&M=65&Ct=BA&SbCt=BA_15_65_BA_15
https://www.motobins.co.uk/bmw-parts.php?model=F Series&bikeref=F650CS

Glad you are having a go. I am also an IT guy and no mechanic but enjoy pulling bikes aparts even if I have never done a full engine rebuild.

My engine looks like yours, although still the original paint. I once had a Honda dominator (650 single) where I got the whole engine bead blasted, then I hand sprayed it with VHT engine paint. The covers I took off and did seperatley. Looked OK actually.. the only mistake was forgetting to blank off the thread holes where a oil return clamped down. It got filled with grit and then ruined by numerous attempts to repair
Soda blasting might be an option to safely get rid of the old paint.

 

[joderest]

As the engine is out, now is the time to do it. Rub the whole thing down, using wire brush in a drill, then wet and dry, you are looking to have a nice clean alloy surface, mask up all the "holes", then give it a good coat of self etch primer.
Then its up to you, people like to spray with smooth silver hammerite, but you could use something like alloy wheel paint, which would be harder and resist chips better.
Good luck

 

[klemkas]

Oh my god, i was so scared and so happy today.
I think everyone knows about old gs fork issue.
http://www.advrider.com/forums/showthread.php?t=371650
http://www.f650gs.crossroadz.com.au/FFIntro.html
I had fork tubes replaced first thing i bought it in a motorcycle service. Today i found this crack when finished disassembling the bike. I think the service did this by over tightening the bolt, or it was already there and they didn't say anything about it. Thank god nothing happened when i was riding...

And the bike turned into lego parts:

 

[hubbaloo]

Wow you seem to have been pretty unlucky with this bike. Perhaps having to strip it down is a good thing, so you can double check everything. Sounds like the last service it got was pretty bad too! Good luck when you get round to the engine.

 

[Buzz]

Today i found this crack when finished disassembling the bike. I think the service did this by over tightening the bolt...

I reckon that's the answer.

It doesn't seem to have failed in the way most often reported - with the whole web breaking away from the fork.

Trying to look on the bright side - at least it's a good opportunity to upgrade to the modified fork design from post '02 where the web is braced more.

You are having a 'mare with this bike. I hope you're enjoying the spannering nearly as much as riding and that you get a good result soon.

Buzz.

 

[joderest]

Oh Boy. I agree, seems like an over tightened issue, have you tried removing the bolt ?, odd, because they normally strip before causing that problem, could be it has taken a hard bash at some point.
In the third picture, that is really stripped down !!!!!!

 

[klemkas]

So much work, i don't know where to start, so i'll try to start from the engine.
The reason for this massacre - counter shaft seal sits happily under the blind bearing, and both counter shaft bearings look stiff and make grinding feel when turned, i'll want to replace them. Good that they are skf and have codes on them 6304 etn9/c3.
I have one more problem in the engine. The main shaft/crankshaft journal/plain bearing bushes/shells are scratched: (i'm lost in all these terms and names)

I think they definitely need replacing. But the size of bushes should be 48x52x22.8mm. I tried measuring the crankshaft by the rotax engine manual and f650gs manual. Both say, that "main bearing journal" diameter should be minimum 47,97 mm, but mine is 46mm! and the bushes hole diameter in the crankcase is also almost 46 mm, they match. If i buy new ones with 48mm dimension, the crankshaft will have a 2mm free play! They cost 50 pound each at local dealer, or 30 pounds at motobins.co.uk (though theres only right side one). If they won't fit it will be a big loss.
I don't understand why there's a difference of 2mm. It couldn't grind off so much, impossible. Do i miss something? Or i'm lost between all these naming conventions? Or the bushings in the crankcase are fatter than oem ones? Can i find bushings elsewhere, maybe there's no need to buy oems?
Need advice..

 

[komatias]

Sell the parts and get a bike that works.....

 

[klemkas]

Sell the parts and get a bike that works.....

Where's the fun in that? It's a great challenge, only bad thing is, i can't do it alone, i lack the knowledge and experience..

 

[Buzz]

I've looked in my Haynes manual:

Crankshaft and bearings
Main Bearing Journal Diameter (Min) 45.975mm
Main bearing bore diameter (Max) 46.08mm

Sounds like your journal is ok?

Buzz

 

[klemkas]

Thank you Buzz!! Then the manuals i have are for some other model i guess.
So my journal is at the minimum. I found out that there's a workshop which can make bearing bushes by measuring journal and engine.
Thanks again, i probably need to buy that haynes manual for my exact model

 

[klemkas]

I contacted that workshop by email and they said that they do not recommend making custom bushings for powerful cars or motorcycles with lots of torque and high rpms. But they can do that.
I think its either that or looking for used crankshaft. The crankshaft is at the minimum (45k miles and already that?? FAQ says they should last 200k miles before needing major repairs..)
I don't think that oem bushings would fit, the journal is quite rough and worn. It is possible to polish the crankshaft, then make custom bushings, and i think it would be better that fitting new bushings to a grinded crankshaft.
The f650gs does have a bit of torque (60Nm), but not much horsepower (37kW) or rpms (6500rpm), does anyone have an opinion on custom bushing and crankshaft polishing? Can this solution be unsafe? Or where can i find some testimonies of people who have done that?

 

[kuyajonathan]

6,500RPM? My 2003 GS/GD has readily goes to 8,000, they are short stroke motorss designed with that kinda rpm.
Sounds like you have pretty severe wear, pretty unusual, as you say usually good for 200,000 miles with servicing.
Wonder if its been from BMW off road school or similar, engine running its side, starved of oil? been few like that according to some recent posts

 

[klemkas]

Well i just took the number from specs, max horsepower at 6500rpm. Max is 8000rpm, but i never drive to max. It still is less than other bikes, my 125cc has max of 12000rpm, but i drive it up to 8k-10k.
I don't know the past of this bike, i just know that it was dark It was imported from UK. And it was serviced very badly or never, some of the owners did not love it at all. Rear shock is rusted, all bearings are rusted, front forks were bent and had lots of hammer punctures, air box had lots of holes to suck unfiltered air and so on.. Don't know about the oil, but except the crankshaft, other parts of the engine look like new, i'll probably have to take out the piston also for checking the rings and cleaning the black stuff, but its scary not to break the rings, i'm delaying it as far as possible....

Komatias is not the first person telling me to sell it for parts and get something else. But i want to overhaul it and have for myself. I get no support except for my girlfriend who says all will be ok And some members of this forum who already have helped me a lot.

The engine is the most important and crucial part, its scary to do something that may result in seizing and crashing. But at the same time this needs to be done for reasonable amount of money. Custom bushings are half the price of oem.
I cannot find information from people about crankshaft overhauls, only articles saying that it is doable like its nothing unusual.
Well if the worst comes to the worst, i'll try to scrape the money and buy another used engine.

 

[hubbaloo]

I wonder whether it might make more sense in this situation to source another engine as cheap as possible. If you are lucky perhaps it will cost less than you think. I saw this on ebay which is from a CS but should be the same.

The rest of the bike will be easy to put right yourself without the same concerns.
Although I like your attitude trying to fix it, you don't want to end up spending a load of money on bearings and rings only to find more problems.

 

[klemkas]

Ha, that's it, end of the line. The crankshaft can not be disassembled, i think. At least at home. So i cannot get it polished without taking of the conrod. Let's say i buy another engine to find out that the crank is worn too. I end up with same situation. I'll try to ask if maybe they can polish it with conrod on, and look for more shops who specialize in crank repairs. I don't give up, but for now i'm stuck. Already gave up the frame for sandblasting and painting. Don't know if should cancel that.. Argh..

EDIT: That shop refused to polish it with conrod, says it has to be removed. One dead end..

 

[komatias]

The crank is pressed on sou you need very special equipment to remove the con rod.

I am not sure if BMW even sell the crank in bits.

the best course of action in my mind is to source a good second hand crank with con rod and buy brand new bearing shells. Speak to Motorworks in the UK.

With a new crank you will need to find out what shims to use but that is covered in the BMW repair manual NOT THE BLOODY HAYNES ONE!

 

[klemkas]

That's the whole point, to get a GOOD second hand one. I saw one on ebay for 300 quids, but it looks even worse than mine, all scratched. There are one or two CS for parts on sale locally. But i can't get inside the engine to check it out before buying..
Of course they don't have crank parts, i checked. It's probably factory made and only rotax factories have the parts. Rotax manual says it's not serviceable, need to replace.
I have one more idea.. To polish it myself somehow and then take it to the shop to make the shells, haha :riding: I know, i know, all the science behind it is scary, it just popped into my head, but i saw on the internet people do it. Damn, after all, they somehow do restore super old bikes or cars, there must be a way. I'll look for other shops, maybe there's still a chance..

Haha -> https://www.youtube.com/watch?v=j7DZxqPUQto

 

[Buzz]

Did you ever figure out what was causing the oil flow problem?