The 650 Dakar Thread

Hi, its me again, the unlucky guy whose bike swallowed a wellnut on the third day of ownership. Well I got the head off and found brass fragments all around, including in the exhaust pipe. There are small indents all over the head and piston, where the nut got bounced all around for a few seconds only. I can't believe how it has been so pulverised. Otherwise everything looks ok but best get the valves checked for bend I guess. Any opinions as to whether I should do more than just that? Cheers I'll post photos once I've shrunk them.....

That's impressive. What's the chance of shavings getting into the bottom end of the motor ruining it? Pretty reasonable I guess as from memory the head is all open via the cam chain cavity.

Maybe dump the oil and filter it for shavings and check the filter for it. I've been told once that it's a good idea to flush a motor with diesel to clear all the oil sludge out of the galleries. But personally I don't like the idea of dispersing oil sludge through a motor. It's one of those ongoing debaters from googling it in the past. Like oil additives.

Are those side racks connected to each other? From the pictures I'd thought not. In that case, how do they hold up after having landed on them?
I've just built my own in a similar design, and from my experience with hard luggage I've had issues with not having a bottom connection tube. I'm hoping that with soft luggage this won't happen. This time I went for a design with no connection between them.

No, they are not connected.

They are held up by three bolts. This is not the best of pictures, but I hope you can see the connecting points. The loops on the top cornes are well worth making ! I use them all the time.

1. Rear sidepanel, next to the gascap (on the RHS)
2. inside the fender, down abit
3. Back of the subframe, up by the taillight

Here's another picture, again not perfect, but you can see the rear mounting points. The tubes go in behind the plate and make a 90^o turn and go straight up. The bolts are just above the plate



They're made from 20mm tubing (bit overkill), and they've taken everything I've trown at them so far including lowsiding at 70km/h, riding 26.000km with full luggage in "one go" and a few other crashes on MX tracks and in the woods





Let me know and I'll get some better pictures..... closer to summer when I get the bike out of storage

I did my waterpump replacement yesterday. I warmed the bike up until the fan cycled on and off and rechecked the fluid and all appeared normal. This morning the long radiator hose that runs down from the radiator to the water pump was collapsed. What the heck is up with that?
Barry

my guess is air in the system, did you burp the pipes and loosen the bleed screw? if you didn't do both of those you'll have air in there somewhere

The air expanded when hot, but contracted when it cooled down, hence the collapsed pipe.

Time to replace chain and sprocket and was wondering if there was anything better then stock OEM? Also was toying with the idea of changing my gearing. I thought I would gear up so I would have a smoother ride at highway speeds and when I am on the logging roads I am mostly in 1st and 2nd. By gearing up I could stay in 1st gear longer and avoid having to continuously shift between 1st and 2nd. Not to worried about losing the bottom end torque since I think I have enough torque already for my style of riding. Any thoughts for this novice rider?<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>

My friend in Florida has 52k miles on his 650GS. He has been using Sprocket Specialties Tital Tough rear sprockets on his and loves the long service life. His recommendation to me which I have taken is to go from a 47 to a 45 rear. I put mine on this week but haven't ridden it yet.
Barry

I did burp the pipes and bleed the screw but you have to be right. I'm headed out there now to bleed the screw one more time. It has to be trapped air.
Barry

That's how I built them as well out of half inch tubing to keep it a bit lighter. I've made jigs for when they break. Could always make them a bit heavier.

I was going to make those loops on the inside instead. For things like Rok Straps and a loop in the middle for Andy Strapz. Should give heaps of functionality.

+1 on that. I also use a 17 counter shaft sprocket for long trips.

While I agree that an oil change is in order, I can't see how anything internal to the cylinder can get into the cam chamber above the head (and then down to the bottom end) - unless there has been catastrophic head failure somewhere. The inlet and exhaust ports are open only at the intake and exhaust pipe and the cylinder (when the valve is open), and the spark plug port(s) is plugged by the spark plug(s)! So no way for foreign material to get into the bottom end without either blowing past the rings ( ) or blowing a hole in the head ( :eek1 ).

Or have I got it all wrong... :huh

But the material came in through the inlet manifold. So to get to the exhaust it would have to have gone past the valves into the cylinder. Meaning that it would be in the top end. So from that I guess it could have travelled to the big end/ bottom end of the motor. Not sure how the cavities are down there though.

Yes you can simply change the rear. In a perfect world we would have two sets of wheels/tires with a 47 or lower ratio on the rear with off road friendly dot's. Then all we would do is change wheels/tires and be ready for Interstate tours or dual sporting. I just returned from a nice 50 mile ride in some 22 degree temps. The gearing is fabulous thus far. I can still loft the front wheel with the 47 and the power feels just fine.

I just changed sprockets and chains. I have no experience with this change but I used an RK XW ring chain. It is an X ring change with three sealing surfaces and the metal is hardened. RK says with equal use and care it is capable of exceeding the life of their non hardened chain by a shocking 100%. I'll have a full report on that in about three months or so. The Tital Tough hardened sprocket and that chain has the potential to extend my chain life a bunch. I also ordered the really cool looking chain oiler from Rider Warehouse that has that little primer bubble like your lawn mower carb. A good friend of a buddy of mine just got almost 40,000 miles out of a chain on a Tiger 1050 using that. He says when he gets into a town and is going slow he gives it two or three pumps and keeps his chain well lubed. I'm liking the idea of not having to lube my chain nightly on a 500 mile day or midway on an 800 mile day.
Barry

You were 100% correct. I just opened the bleeder valve and heard the hissing sound as air escaped. The water hose filled right up. I went for a 50 mile ride and will it cool back to completely cold and do it one more time and should be set. Thanks.

I love this thread.
Barry

I just replaced my rear sprocket and chain. I shopped around and to my surprise Touratech had the DID 520 at a fair price. Also a selection of sprockets. So I would check that out. Install was easy. I went to a 49 rear with the stock front 16. I really can't answer your gearing question, but unless you're doing long distance, lower gearing has been great for dual sporting.

I would definitely to a full oil change. Also consult with someone on F650.com
Since your oil pan drain magnet won't pick up the brass, I would use a strainer to see if there's anything in your used oil. Err on the side of caution.

The only path from the inlet/exhaust track and combustion chamber into the the cam galley would be through the valve stem guides. Not likely. In order to get into the bottom end from the combustion chamber, you have get past the rings. Not likely.

But then...

You're right. I was mistaken. Somehow I thought that there was a link between the valve head and inlet. But yeah, would have to go past the valve stem, shim bucket etc. Not likely. Wouldn't be a bad idea to check under the shim bucket for some shavings though.