77 WR250 back from the dead

[rich196]

Chrome bars, right? Some guys swear by polishing chrome with aluminum foil. Google/youtube it.
And, I was referencing using the measure of your bike's origin (metric)

I knew what you meant.
I'm taking subtle corrosion and dirt off the chrome. Al foil won't do it for that but it's a good trick.

 

[rich196]

Ok I got the bars cleaned up pretty well with a fine wire wheel.
My next obstacle is the exhaust. I took it apart and am having it bead blasted.
Are the internals available anywhere?
13 in the diagram is shot.

 

[grouty]

That is the spark arrestor. They are a right royal PITA ! I have one on the back of my 390 Auto. I removed the centre gauze to stop it choking with carbon. I have plans to make a short perforated tube to go in there with some wadding as an extra silencer. Yours looks to be still usable so long as the centre gauze is gone.
My exhaust was very rusty when I got it. I wire wheeled it back to bare metal and sprayed it with PJ1 satin black. The front section to the first up joint I did with PJ1 Flat Black for the higher temperature. I let it dry for a week and then coated it liberally with Duck Oil. This will bring up a nice "O.E." shine and make it all look the same. Still looking good nearly 2 years later.

 

[rich196]

The whole thing was stuffed with clumpy oily packing and I think the airflow was severely limited.
What is the material?
So should I hammer this one out or look for a replacement?

 

[suprize]

part 13 locates the silencer tube in the exhaust. I would replace the tube part with perforated tube and wrap with glass packing or steel wool. you will need to fix #13 or cobble up another supporting ring for the silencer tube

 

[grouty]

The best way to clear the mesh inside the spark arrestor is to attack it with a blow torch. Best to do it outside !!! Get it cherry red and be prepared for smelly smoke as the crap burns off. If SWMBO is in residence ..... take it as far away down wind as possible ! Once done give it a bang on the floor to bump out the debris. Refit and ride ..... Oh, if you ride it for a few hours, be prepared to do it all again. Best to knock out the centre mesh as I said earlier. Then it cannot block up and restrict the motor.

 

[suprize]

that "smell" of burning exhaust can be detected in the tiniest of concentrations by women....make sure you are a loooong way away from the house or that's when the trouble will start

 

[rich196]

Oh man my wife has the nose of a shark and bad allergies.
I'll do it way out in the yard. Thanks for the tip.

 

[rich196]

part 13 locates the silencer tube in the exhaust. I would replace the tube part with perforated tube and wrap with glass packing or steel wool. you will need to fix #13 or cobble up another supporting ring for the silencer tube

I have all the other parts in the diagram too (10-12) so I have the perforated tube.
All of them are caked with oily sludge which I already tracked into the house and it was painful when the wife discovered it was from me.
If I understand 13 is just sheet metal lined with mesh. I can probably reshape it.
When I do repack it should I use exhaust specific material or just any fiberglass or steel wool? Also should I use stainless wool over carbon steel?[/quote]

 

[grouty]

Just use the mat type of packing. Roll it up so it fits in the tube not too tightly. I usually put a couple of pieces of masking tape around it so it keeps it's shape as I stuff it in. My perforated tube is welded in, so does not come out !

As your tube is free, I would attack that with the blow torch and a wire brush too. Sounds like it would be a good idea to take it all round to a mates house and burn it there. Over a few beer's of course

 

[suprize]

Over a few beer's of course

of course.....

 

[Crashaholic]

Part 13 is a skyway spark arrestor insert currently found in the aftermarket Cobra/Sparky spark arrestor. New ones on Ebay are running $100 but once in a while a used one pops up for far less. The best method to remove carbon from the screen is a good gasoline wash followed by a fine bead blast, must be careful not to blast the screen to oblivion. Any exhaust system off of any kind of motorcycle that has a sparky/cobra will have the same insert as part #13.

Heres a new one for $50, you'd better grab it.

http://www.ebay.com/itm/Sparky-Cobr...ash=item1a1cc5ffb5:g:MwIAAOSw8w1X7Eko&vxp=mtr

 

[rich196]

You mean the inside part of it?

 

[Crashaholic]

I'm referring to exhaust part #13 (spark arrestor) in the parts view above. You mentioned yours was shot.

 

[rich196]

I'm referring to exhaust part #13 (spark arrestor) in the parts view above. You mentioned yours was shot.

Yes mine's crushed as shown in the pic. So do I get this assembly and use the insert in my housing?

 

[Crashaholic]

That's correct, the insert will slide out of the Cobra Sparky with a little heat applied to the aluminum housing.

 

[rich196]

That's correct, the insert will slide out of the Cobra Sparky with a little heat applied to the aluminum housing.

That's so cool thanks for the info.
I got that one for $30!

 

[rich196]

Back to shocks, I got a quote from Ohlins for a set of CC 607's. The price is $864.

 

[Eric The Leg]

Back to shocks, I got a quote from Ohlins for a set of CC 607's. The price is $864.

To be completely honest, that sounds pretty darn reasonable. I dropped $750 last fall getting the rear mono shocks on 2 of my bikes serviced. Suspension work is expensive, but generally worth it.

 

[suprize]

I thought it sounded ok as well...snap em up!