A A A A Author Topic: CX500 Eurosport restoration LT / The Shed build  (Read 649 times)


CX500 Eurosport restoration LT / The Shed build
« Started on: 30-Dec-19, 18:52 »
Hi everyone,

I am located in Lithuania (we beleive that it is center of europe).
I have '82 CX500 Eurosport that is meant to be restored and possibly put some cafe racer touches to it.

I start this thread to post my progress and possibly get some constructive suggestions on how to do it and do it better.

Jobs to be done:
1) solve  preasure blows back to one carb;
2) overheating coolant
3) electrical problems ( no short lights)
4) front fork oil leak;
5) gear shifter oil leak;

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Now sitting with problem No1.

My research on the web and some suggestion from CX500forum members showed to burnt intake valve.
So i took of valve head.
From first inspection (and water leak test) this theory did not confirm.
I am about to disassemble the valves to see if the seating is ok.
Few pictures:
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its a learning experience-haven't tackled a CX full rebuild myself (only CB250s and CB350s..lol) so can't advise a lot....
good luck

Suggest any specific technical questions to "ask the gurus" -they are always helpful especially if you have already done "basic research"-all the best.


Ok. Long time have not been on the forum. Although have spent more time in the shed.

Done cleaning of the head, valves and all around.
Done valve lapping. By hand. Not a lot of fun when you tell your wife - but it's a guy thing...

New stem seals, new gasket from Davidsilverspares.

No photos - i am not much of a blogger.


The most interesting and frustrating thing is - after I have ripped the valve head off. I did not find any burnt valves or similar.

And then, somewhere in the wast internet I found, that blow back to carbs might be because of bad spark plugs.

Change the plugs - problem disappers.

Well at least i now know how a piston looks like in person :)


Good to hear you have found and fixed the problem.

These engines are fairly reliable and the common problems are weeping water pump seals and broken cam chain guides and broken cam chain tensioner if you allow the cam chain to wear too much.



Ok. Story continues.
My bike is very hard to start after sitting for a few days. Checked the battery - it is only about 6ah and 100a starting current.

Today got a new battery as per specs.
Still very hezitant to start. Starting is very weak and if some throtle is addet it immediately stalls. when wormed up - starts immediately.
Lean mixture?

Also found out one intake manifold is leaking air...
Any suggestions how to fix it? Or look for new one?


Any CX with reluctant starter issues first needs this simple modification...
Do this before any difficult process.  If you look around the forum you will see several methods of doing this mod.
"Young" Les F


The other thing to try to make starting easier is to either drain the carburettor fuel bowls OR turn off the fuel before turning off the engine.

This will allow fresh fuel to flow into the carburettors when you start the engine which allows a quicker more reliable start.



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