Australian 1981 XJ650 4K1 - advice

Tonight I started cleaning up my bike and a few things caught my eye.

1. To me, this collector like it has been patched.. is that the case?

2. After stripping and cleaning the carbs I noticed the PO had set mixture screws to 2.5 turns out. Plugs indicated that the bike had been running rich+ so I did some reading and mix screws are coarse thread so I have reset to 1 3/4 per instructions here (waiting on colortune plug) as a result headers and exhaust ports seem caked with carbon.. is this normal or more likely due to running fat? Any advice to remove the build up? I was going to use die grinder with a wire wheel on the ports and intake cleaner on the pipes?

3. There are some dints in the headers and one small perforation that I have found so far. Should I try to fix the dints and tig the holes or am I better off finding another exhaust?

Any advice on these issues would be welcomed and appreciated

Kind regards
Paul

 

Looks like a riveted patch to me also. No idea on what is 'normal' for a collector, but that build does look ugly.

Sit tight one of the gurus (or not a guru) will show up and shed some light on the subject.

 

Thanks Stumps. I can assure you it is even more hideous in person. I was hoping to blow some crushed glass at it and give it a paint but im having doubts that it will survive the process :/

Btw, does anybody have a tip for safely lifting the bike on a jack stand without fear of crushing the exhaust of having to remove them?

 

1. Yes it was patched. Looks ugly, but sound.

2. You got i right, the PO did not. The crbon buildup will be mostly from it running rich. Normal is a light coating of carbon soot. I'd recommend using a center punch and a vcuum cleaner to scrape the big hunks off after soaking with a 50/50 mix of acetone and automaic transmission fluid. If you use a Dremel, use a wire brush attachement.

3. That would be up to you and your budget. Small dings won't affect performance; small holes will.

 

Lifting the bike with the exahust on: don't.

Place it on the center stand.
Strap the stand to the frame so it can't collapse on you.
Strap bags of sand or other convienient weight onto the rear of the seat.
Watch in wonder as the front wheel lifts off of the ground.
If you need to have both wheels off at the same time, just remove the rear first and use a pair of jackstands for the swingarm to land on.


I have an aletrnative method to use a bottle jack on the front, but you'd need to make an adaptor plate to spread the load on the engine case.

Another option is to fabricate a front paddock stand that uses the steering neck as a lifting point.

 

Thank you k-moe. I was going to try the acetone/tranny fluid in the pots as well as I had low compression after an initial check. I thought it might be from sticky rings however since then I have the valve clearances set and have tightened what was a very loose timing chain. I have yet to do a compression test after fixing those things so it may be ok when I check it again. Question.. if I did put the mix in The hot side and plug holes will that mean a mandatory oil flush and change once im done? Or do i drop the oil prior to doing this?

Comp numbers were 115 95 100 120

As far as I know fine glass grit wont be too abrasive for the pipes so it looks like thats the plan, then pressure test for holes ant tig the leaks then some high temp paint to make it look half respectable

For the jack stand - I really like that I can get the bike right off the ground so maybe I could weld some lugs to the under side of the frame do they are the low points in contact with the jack.. thoughts?

 

I'd prefer to see a plate made for the jack that has raised cups to rest the frame on. That'd be useful for other bikes, and you wouldn't need to repaint the frame of the motorcycle.

 

In reference to the 50/50 acetone tranny fluid.

Anyone able to advise on this? Also would it be a good idea to use the same for cleaning the heavy baked on carbon out of the headers? I wonder if a spray bottle with the mix in would be the way to go?

Edit: Bonus pic of one of the plugs that were in the bike when I bought it.. this is one for the wall of shame

 

Aaaaahh!

That's one for the PO's Gone Wild thread.

 

Ewww.. ICK.

That is full of crud. Looks like oil and sludge. Maybe someone already soaked the cylinders and that is the result. Hopefully it's not a sign of badness in the oil-sealing department (but I'm afraid that's what it will be).

 

It had been leaking oil externally at some point as there was a receipt for a mechanical check which stated that. Im not sure what was done to fix the leak. PO mentioned that he switched to synthetic oil but couldnt tell me what weight he used. When I pulled that plug I was pretty worried so I stuck a scope into each of the pots to check em out. Cyl 4 was my main concern as thats where that plug was and I couldnt see anything unusual on the crowns or the back of the valves.


Thats from #4.. piston crown and intake valve.. anything not right?

The head bolts dont look like they have ever been touched so I might try backing them off and re torque them.