Bringing an Across Back to Life

Tried to start her today...wouldn't go, so I decided I better do a compression test because I had spark at each plug and I had fuel going through so all that was missing was compression.

So on a cold engine the compression results were:
Cylinder 1: 80
Cylinder 2: 100
Cylinder 3: 75
Cylinder 4: 95
(I'd put a teaspoon of oil down the spark plug holes when I replaced with the spark plugs to try and increase the compression before I started her, but it wasn't enough )

Time to pull the head off and see what condition the rings are in.
I thought this may be the case with a bike that's been sitting out in the weather for 2-3 years. Especially when the extended storage procedure hadn't been followed out by the previous owner)

 

Yup

 

Bike has done 43500kms.

I've checked the clearances already and they were in spec.

How do I do a leak test on the valves?

 

I'll have to buy a leak down tester then

Replaced the fork oil and seals today.

This blokes rebuild thread is a great help: http://www.aussiestreetbikes.com/forum/showthread.php?t=11922

I had to get Dad to weld a nut to a long bolt with a 24mm hex head on it so that it could hold the damper rod; similar to the one that guy made on page 2.

Need to learn how to weld one day.

 

Took the head off tonight...piston rings look fine. None of them are stuck/seated into the piston allowing lack of compression.
The valves and piston head look a bit carbony. I'll try and upload some pictures tomorrow when the USB thing stops playing up.

May need to fine hone the cylinder bores, clean up some of the carbon buildup (Brake/carby cleaner?) and use that grindy paste on the valves to seat them a bit better?

Guess I should have done that leak down test hey...

 

Thanks Murdo, will do that!

Head gasket doesn't look great so will be replacing that.

One 2 of the piston heads they had some buildup of carbony crap. It didn't look rusty but didn't look 100% carbon.

 

Also one of the cam journal bolts snapped the threaded part of the bolt off when I was undoing them

 

Here's a few pictures:



Honing doesn't need re-doing?



Carbon build up more than usual?
3rd cylinder:



1st cylinder:

 

Got the pesky bolt out. Thankyou Bosch easy-outs from Masters

Cleaned the carbon off the bottom of the valves tonight and put some fuel in to see if any leaks out overnight (Thanks Murdo)

 

Small update...got a replacement cam journal bolt and head gasket a few months ago.
Decided to hone the cylinders out this afternoon as they didn't really have any cross-hatching at all.

Now to put her back together and hopefully it'll start...

It's been too cold over winter to tinker around in the shed after work

 

Finally pulled my finger out...put the honed cylinder, new head gasket, head, cleaned carbs with new jets back on today.

Went to fire it up and no luck

Got fuel, had spark last time I tested.
Will need to do another compression test to see if it increased after the honing & cleaning.

If still low then I'll had to do a leak-down test I suppose.

Will con Dad into helping me trailer it to a hill so we can do a few push starts down the hill & back again.

If that doesn't work then I'm all out of ideas.

 

Guess what...
Got the old b!tch started.

I opened up the tops of the carbs and cleaned the black needle holder things as they had a bit of oily residue left on them.
I then sprayed some aerostart in there.
I then put the battery from the CBR250 instead of my smaller battery off the WR250f.
Cranked her over and she started pretty easily.

Then there was smoke...some from the headers as I had painted them black in that heat-resistant paint but it requires a few minutes to 'bake' on. But also some left over oily residue from when I pulled her to bits was probably burning off the outside of the engine.

The exhaust also had quite a bit of smoke, I assume a decent amount of this was from oiling the cylinder after honing it.

I could rev it and she'd slowly work her way back down to idle. Wasn't as smooth as the CBR with the push/pull throttle cables. The across only has a pull throttle cable.
Plus I think I need to tighten up the nuts for the throttle cable as I had one rev which went OMGWTF16KRPM so I turned off the bike via the key whilst nearly sh!tting my pants as I didn't even have my hand on the throttle anymore but she was still climbing.

I'll try and put up a short video soon.

I think I need to shim the front brake pad as the caliper is scraping/dragging on the rotor.
The pads are from PyramidParts and aren't genuine Suzuki pads so maybe they are slightly thinner on the back part of the pad (ie. not the meat of the pad part)
Reckon I can fabricate a thin piece of sheet metal the same size as the pad and sit it in between the pad & the brake pistons to sit out a bit further to stop the scraping?