Honda CX 500
This is a typical enquiry that we receive on a regular basis. I feel it important to air this on our blog as it shows good reciprocation of information between us and the customer (Simon). Simon initially gave me a breakdown of all the problems suggested by another mechanic such as a knackered crank.
My reply was given on the 14/7/13.
“You can bet your bottom dollar that the crank will need a regrind if the rods have gone and this will need undersize big end shells, small ends and pistons rarely give problems but rings and barrel can get worn out. This is all fixable.
The cost of a strip down would be about £250.00,
A crank grind, at about £80.00,
Undersize shells are about £40.00 but I have had some on eBay for a fiver total,
A barrel rebore and hone is £60.00,
A set of rings can be had at about £20.00,
To put back together would be in the realms of £520.00.
In the past 20 years I have built 7 of these engines as my record shows and one of them replicated the noise that you mention if was found that the main shaft bearing was knackered and this was the only thing that needed renewing. Total £970.00 if all is bad. I don’t know of any engine restorers in your area that could give you sound advice or an estimate on cost, you will find we are the only company in the UK that has the experience in engine restoration and rebuilding that would even hesitate to give guideline cost. Good luck in your quest
P.S. If the guy cant give you a guesstimate cost he does not know his engines.
Kind regards terry”
John replied on the 15/7/13.
“Many thanks for the response and you’ve convinced me that the old CX motor just needs the right amount of care and attention to bring it back to life. I think you’ve gathered that I’m not looking for a full clean up and restoration, because I want the enjoyment of dong that my self, but I do need the internals bringing back to life. I’m not convinced it’s as bad as the main dealer suggested; he listened to the engine run for about two seconds and then declared it knackered. He was trying to convince to buy a bike of him I think.
So now you have got me committed to breathing new life into the CX how do you feel about tackling the project? I’ve not come across anyone any one who gives me the same level of confidence that the bike is in good hands. I will aim to try and get a local transport company to deliver it to your work shop. I will do everything I can to help you source parts David Silver is a very good person for this http://www.davidsilverspaires.co.uk. I will also promise not to hassle you for a quick turnaround and I guarantee I’ll pay you promptly.
The 970.00 is defiantly at the top end of my budget but I am hoping that the problems are not as bad as I have been lead to believe and lady wife’s bathroom refurb will have to be chopped away a little but if you’re up for the challenge we can set the wheels in motion.
Let me know what you think.”
I said 16/7/13
“Bring the bike down when it best suits you. Phone us on 01767318509.”
John said 17/7/13
“Terry I have a bike transporter booked, just need to be sure you are available to take delivery. Is a weekend better for you or Saturday Afternoon?
Also I have a PDF of a CX service manual developed by Honda for US mechanics, wouldn’t say it’s perfect but it might be useful for you, I can send via web file transfer (26meg file) if you want to have a look. Just let me know and I’ll send.
Can we also come to some agreement about payment? The first step is to diagnose the problem and then you’ll need cash to source and buy parts and I don’t want you out of pocket so maybe some sort of upfront payment to get things moving is the fairest method. Let me know how you want to structure this? I am flexible”
I replied 17/7/13
“£500.00 up front payment would be handy.”
The Honda CX 500 was delivered on 2/8/13 with a letter
“A bit of background info that might help you with the CX 500.
I picked the bike up 6 weeks ago and rode it from Nottingham. It was running rough. There was a hole in the exhaust header pipe that I initially thought might be the source of the noise. I’ve replaced the head pipes but the noise is clearly the motor.
Previous owner told me the tank had rust in it and he’d cleaned it out with acid and put a filter in the fuel line. Also he’s taken the carbs off and done a bit of cleaning up. I don’t think he has reset them properly though.
First thing I notices was fuel dripping out of the pipe below the main stand when I stopped. Suspect that there is a float sticking.
When I got it home I changed the oil and put a new filter cover seal and filter cover bolt o ring in. the filter has only done about 15 miles so you could probably reuse this item if you want to.
I also adjusted the cam chain and tappets and notice the left hand exhaust tappets. Setting the correct gap hasn’t improved the sound of the engine thought. Cam chain adjustment hasn’t helped either.
There also a secondary intermittent noise that sounds like it’s coming from the radiator fan at around 30 MPH, which is attached to the crankshaft. This may be a symptom of a crank problem guesswork on my part though – could just be a damaged or badly fitted fan or radiator part.
Handlebar kill switch is very loose and has been an issue when trying to start the bike; I intend to replace this soon.
You have the only ignition key as I don’t have a spare yet.
If you want me to chase parts for you I am more then happy to, just let me know.
Good luck with the motor
I reported my findings 2/8/13
“Received your bike and attacked it with gusto. Firstly I drained the oil and flushed out the engine I then removed barrels and I was able to inspect the crank play on the main bearings I found less than .001″ play. I checked the cam shaft using a stethoscope and found it to be in excellent condition with no appreciable wear. Cam followers again in very fine condition. The pushrods and there ends were as new as if they had been changed recently. Piston rings show no wear and the end gaps are well within tolerance. Conrods and there big end bearings showed .001″ wear. The barrel bores still have signs of honing. The tops of the pistons show that it has run a little on the rich side over some time which is certainly not a bad thing. The piston on the left hand side had marks on the top from the exhaust valves hitting on it. I checked the exhaust valve guides and found them in very good condition but the valves were not seating properly so I re-cut and ground the seats in and checked that the valve stems for straightness. All was OK on the right hand cylinder. I thought It prudent to check the clutch for wear and found that the four spring pressure bolts were well under there torque settings. The clutch plates were in fair condition so we cleaned them in the aqua blaster. The header pipes that you fitted still had the old copper seals in place. You naughty boy you forgot to take the old ones out before fitting the new ones this allows blowby throughout the exhaust system. The balance pipe had three holes in it so we have covered this with a stainless steel plate, they usually rust to pieces but yours isn’t bad. We removed the carbs as this is a bastard of a job even with soft rubbers and found that one of the float needles was not seating so we replaced both needles with modern ethanol resistant Viton ones. We also found a seal and thrust washer missing on an air mixture screw. And the cabs were not in balance. The fan problem was found to be a distorted fan housing that we have put right. I have also sorted out the ignition kill switch; it will give you no problems. There is too much to write at this time in the morning and I must go home now and have a shower. Your bike will be test ridden on Monday morning and will be ready to pick up on Tuesday morning. Cheers terry”
A reply come back from john 3/8/13
“Wow, fast work Terry. The new header pipe seals I have didn't fit the collector box so I was hoping to get away with it.
Is the cam chain OK?”
“I'll contact the courier and see when he can collect.
Another little line to john 4/8/13
“Worked till 12 midday and started the old girl. She sounds absolutely perfect with a slight whine from the hypoid gear that drives the shaft to the back wheel which is totally normal. She should give you loads of miles of service. It appears that you have got a goodun that has been cared for in the past. Cheers terry. Balance due on collection is £230.00. P.S I won’t lose your key.”
John sounds pleased 4/8/13
“Perfect, thanks Terry. I'll get a cheque in the post ASAP and get her picked up as soon as I'm back. Very much appreciated.
Another CX 500 saved with many miles of riding and enjoyment to come. 14th august 2014
She’s still running well Terry. Fitted a few new parts recently, collector box, shocks, coils, fly screen, rear brake drums, bits and bobs. She’s happy at 70 mph all day on the motorway. Not bad for a 35 yr old eh.
JS “CX 500 owner”