The CX500 Turbo Resurrection Thread

[Hellgate]

Remove the radiator. Unbolt about 70 pounds of rusty, dirty heat shields. Remove the turbo.

Oh, I found out what the reed valve is for. There's a section in the back of the manual about it. It's a way of dealing with compressor surge. When air flows backwards through the turbo, the reed valves shut and the air instead has to flow through a 1/4" hole and then through a small plastic muffler, thus reducing the noise and the rate of backwards airflow.

It seems overly complex to me, since you can add a BOV and get the cool Pssssh noise instead. Honda dealt with compressor surge not by eliminating it, but instead by making sure you couldn't hear it. I find that less than fabulous.

Fred

Hummm...very interesting....:thumbup:

 

[afpreppie04]

Ugh, I went threw those 70 lbs of rusty heat shields when pulling the turbo on my RX7. Not fun, I think I managed to cut every finger that day. New turbo is getting the turbine housing jet-hotted and the heatshields are in the trash

 

[Motogiro]

You are doing an excellent job with these videos!!! I was impressed....very good narating you made it interesting... :thumbup: :thumbup:

Fred ,
Thanks for the work you're sharing with us. It adds to all of our collective knowledge and dynamics as forum members and riders.
We should get you on the Speed Channel!:rockon:

Cliff

 

[Hellgate]

^^^ I agree, this is a great thread. I love working on old bikes.

I dream of resurrecting and old two stroke race bikes...:hug::blowkiss::innocent:

Someday....

 

[Circle]

Remove the radiator. Unbolt about 70 pounds of rusty, dirty heat shields. Remove the turbo.

Oh, I found out what the reed valve is for. There's a section in the back of the manual about it. It's a way of dealing with compressor surge. When air flows backwards through the turbo, the reed valves shut and the air instead has to flow through a 1/4" hole and then through a small plastic muffler, thus reducing the noise and the rate of backwards airflow.

It seems overly complex to me, since you can add a BOV and get the cool Pssssh noise instead. Honda dealt with compressor surge not by eliminating it, but instead by making sure you couldn't hear it. I find that less than fabulous.

Fred

Fred, mate, surely the path is clear, the way is open, and the lane clear to overtake...

"Pssssh" it up old friend. 'Pssssh' like your never 'Pssssh'd before.
Did not a great man once say "A Pssssh', a 'psssh'! My kingdom for a "psssh'?

Having sat next to guys attempting to burn me at the lights, and having to hear their 'Psssh', I think you owe it to the us, the motorcycling minority, to 'Psssh' back.

 

[Fred]

I fixed the fuel leak tonight. It was just a cracked fuel line.

The bike's engine runs like a top.

The transmission sounds like it's full of rocks. I'm waiting to hear back from the CX Turbo folks if that's normal backlash or if there's a major problem with the bike.

The battery is still strapped to the footpeg, so I won't be riding it just yet.

 

[afpreppie04]

Pssh, that just means you have a running board on one side, perfectly ridable!

 

[Fred]

Update time!

Day 6. Fixing the fuel leak. I love the simple repairs. I was all set to repair the petc0ck, but instead I just had to buy a couple feet of fuel line and put it on.

[ame=http://www.youtube.com/watch?v=WJWjUhPsxf8]YouTube - CX500T Resurrection, Day 6[/ame]

Day 7. Taking the clutch apart and maybe finding the problem. What do you think of my diagnosis? What's the solution?

[ame=http://www.youtube.com/watch?v=0DlCFFJ4OtU]YouTube - Day 7[/ame]

Cheers,
Fred

 

[champion221elite]

Great work Fred! I don't have the slightest clue about your clutch noise, but it looks like you're making good progress. My old 1974 Honda CL200 made a similar noise but I didn't pay much attention to it. I put around 3,000 miles on that bike just riding around my parents 80 acres.

 

[Hellgate]

A few observations.

1) Nice cat

2) Your hose is dusty

So when are you going to clean that thing up?

Oh, I meant to tell you this before, near my place is a restored, totally cherry CX turbo, looks better than new. The owner rides it almost everyday. He repainted it red and white, and put on a smoked wind screen. Looks very nice.

 

[Fred]

So when are you going to clean that thing up?

Oh, I meant to tell you this before, near my place is a restored, totally cherry CX turbo, looks better than new. The owner rides it almost everyday. He repainted it red and white, and put on a smoked wind screen. Looks very nice.

I'm afraid to wash it. The water might create more problems!

Good to know about that CX near you. I may need some clutch parts!

Fred

 

[wolfc70]

Nice job Fred! Having owned a CX500C I may have some solutions to your issues, and a few suggestions that may help.

The second coolant temp sensor is for the instrument panel. I believe it goes to the high temp light. Since computer controls were in there infancy when the Turbos were made, Honda used redundancy to ensure reliable operation, and having three coolant temps sensors is a prime example.

The worn clutch basket springs is a common issue. The only cure is a whole new clutch basket since individual parts are no longer available. It is fine to run it as is, it will just try and imitate a Ducati's dry clutch (noisey!) Check the clutch springs too, as they almost always compress and cause clutch slipping down the road. With 43K on the bike, new clutch springs might be a good idea.

Make sure you also check the water pump "mechanical seal" as they are known to leak if the bike sits for long periods of time. Check the water pump weep hole, if someone put silicone on the hole to stop weeping, coolant can get behind the timing chain cover (problem on all CX/GL engines) and into the oil.

Check the stator for proper operation, this is another weak spot on the CX/GL engines. Infrequent oil changes causes acids to eat away at the stator windings. The only preventative cure is very frequent oil changes, every 1-2k miles. The Turbos are even worse, as they have much higher oil temps. Engine must be removed to change and aftermarket stators are available. Check all grounds, for some reason, the CX/GL series are known for ground issues.

Check the timing chain, all early (1978) engines were recalled and had updated tensioners installed. Three dots in the shape of a triangle on the engine serial plate indicate the work was performed. 1979-1982 engines had mechanical tensioners and were adjusted by loosening a a bolt on the adjuster. The post 1982 bikes had spring tensioned adjusters. All of the engines I have taken apart have needed timing chain and guides after 50k miles. All the adjuster were at the end of their travel.

Do a valve adjustment. It is simple but something many people get wrong. Due to the rocker to valve angle the adjuster sits a weird angle, wearing in one spot. This can make the valves excessively noisy, not that they are quiet even when adjusted properly. In an effort to quiet down the valve heads, some people set the clearances too tight, and is a great way to burn the valves.

This should cover the basics, as the CX Turbos are a picky/finicky machine, you may have more issues. Overall these are very durable and reliable bikes, the shaft drive is pretty much problem free, and the engines are very robust if maintained properly. Good luck getting it back on the road!

 

[dturpen]

Awesome thread! I love seeing all the restoration and troubleshooting that goes into the resurrection of older machines. Great work and keep posting those vids!

 

[dean owens]

i know i'm thread diggin'... but what happened to the rest of the thread?