[unbreakable7132]

So I over-revved the bike the other day trying to shift(didn't kick it hard enough). Result, very loud and disheartening chatter from my left head. Removal of valve cover revealed broken valve spring, and a pissed off owner.Of course, Honda doesn't carry them anymore.Any ideas on where to purchase new?

 

[Shep]

Although off a Turbo I think they are the same,



http://honda.yamahaoftroy.com/fiche...ry=MOTORCYCLES&make=HONDA&year=1982&fveh=3405



Also,



http://www.cmsnl.com/search.php?s_name=cx500

 

[unbreakable7132]

The first link is exactly what the kid @ my honda dealer showed me, and when he entered my parts into the system it said it couldn't find the part numbers. A quick call to his tech help line sealed the deal, no longer available. As far as the second link goes, I think it would cost me way more to ship the parts than it would to buy them here in the states. I appreciate the links shep.

 

[Shep]

Like many things on these bikes I reckon they are stock valve spring inner and outer.I bet they were used on other motorcycles and or cars.



Get the dimensions from the manual and then Yellow pages and or start Googling.The valves were used on some Honda cars circa 1980/85 so I bet the valve springs were as well.A good local Motor Factors/motor parts supplier may be able to help.

 

[Shep]

Like many things on these bikes I reckon they are stock valve spring inner and outer.I bet they were used on other motorcycles and or cars.

Get the dimensions from the manual and then Yellow pages and or start Googling.The valves were used on some Honda cars circa 1980/85 so I bet the valve springs were as well.A good local Motor Factors/motor parts supplier may be able to help.



I have a box full of usable ones if you are really stuck but post in the For sale section.Some one on here must have some spares.They are easy to check for service limits with a Vernier Calliper.

 

[unbreakable7132]

I'll get to measuring tomorrow.Oh how'd I love to find some springs in a junkyard motor or something. Good thing winter's on the way, just in case I can't get it figured out soon.

 

[MotorcycleCommuter]

You'll probably have to pull the head and inspect the piston and valves. You likely have more damage than just a broken spirng.

 

[Blindstitch]

Doesn't he have to pull the head to swap the spring? I have never seen one remove that little pin that locks the valve in place without the tool for the job. It can even be had by some autoparts stores free on loan as long as it's returned in a month.

 

[Shep]

Yes the head will have to be removed.You also need a Valve Spring Compressor.These can be dangerous.Be very careful either when removing Valve springs(Face head/Valves towards the floor) or when re-fitting be cautious and never let the springs under compression point towards the face or anyone else.If they slip they go at the speed of a bullet and can quite easily take an eye out.



When the Valve collets are correctly in place and the Compressor is released you should use a soft headed mallet and tap the top of the Valve with the head supported off the ground so it can move to check that the collets have seated correctly.Failure to do so can cause the collects to eject and the valve to drop causing major engine damage.This is usually covered in the manual/s.



HTH

 

[Blindstitch]

I watched Natedawg do two heads last year in his living room. I was waiting for one to fly and go through the tv.



But the local autoparts store did have a loan on the spring compressor. Better than buying one for a one time job.

 

[InWeldingWeTrust]

Its also quite easy to make a valve spring compressor using a goodsized G-Clamp and a bent/filed head attachment, then you have the tool whenever you need it

 

[Blindstitch]

http://www.streetchopperweb.com/tech/0701_stcp_homemade_valvespring_compressor/index.html

 

[MotorcycleCommuter]

The reason I recommended the cylinder head be removed is that a lot of people us an attachment that goes in the spark plug hole to fill the cylinder with compressed air. That holds the valve up while the keepers, springs and oil seals are removed with a special spring compressor. I've also lowered the piston to the bottom and threaded a cotton clothline into the sparkplug hole then rotated the piston back up. The compressed rope holds the valves in place during spring removal.

 

[unbreakable7132]

I know I'll have pull the head.I'm doing a full motor reseal over the winter.So the engine will be in pieces anyway.As far as the tool is concerned, I've been a Master Technician for Nissan for the last 4 years.I've got just about every tool imaginable.Japanese crap is my specialty, lol.I'm pretty sure I just ate up the springs. I found a couple spare springs in a box last night, but I don't know if they are the ones I need(haven't had time to check).

 

[HotFoot]

Bran,



Good luck with with the project. Now if we could only find automotive valves that "drop-in". Hopefully springs will show up from somewhere automotive.



Since you are pulling the whole engine down I assume you are going to remove all the valves. (I know I would just to see what wear there is).

I'd be very interested in what you find especially in regard to exhaust guide wear.



I'm on my third engine dismantle (building a spare). The latest has only 6000 miles on it (according to seller) but already is showing too much slop in all four exhaust guides. The valve stems "mic" almost new. All four intakes are OK.... darn near new spec. All indicators internally in the engine support low mileage. I can still see hone cross-hatch marks in the cylinder walls. No cylinder ridge. Almost no sludge anywhere. No debris in the oil pump pick-up screen.



All the CX heads I've taken apart have shown exhaust guide wear. One engine 23000 miles, one 17000 and now the latest at "6000". Also an eBay set of heads from an engine claimed to have had mileage of 25000. I wonder if the crap we get for fuel is playing havoc with the guides....nothing to lube them even a little (I miss lead... and red gas.)



I hope that Honda, given their pretty good reputation for quality, would not have made guides out of a known inferior material.



Anyway....... let us know what you find. Whats the mileage on your engine?



Hoppy



P.S. All comments from anyone regarding valve guide wear most welcome

 

[holyman1973]

I have a spare motor from a 79 500c. It had about 24,000 went the cam chain chewed up the internals. I could try digging the springs out if you want. It's pretty much a boat anchor in my garage.

 

[Shep]

Most of the spare heads I have have worn valve guides.Of course the exhaust guides take the most hammer/wear.However the engines in the UK tend to have higher mileage and more abuse in many cases.



My present CX has new guides and valves,seats re-cut and the heads were de-coked of course and lightly skimmed by the local engineering company I use.Quite an expensive job even without new valve springs(I had some near new ones within top service limits).This is has cured my excessive oil use on that bike/engine.It has full and good compression/rings/bores.



I suspect in your low mileage case the engine has been abused.



See this thread,



http://globalcxglvtwins.hostingdelivered.com/viewtopic.php?f=20&t=289



Peter has over 140,000 Klm on his CX without new guides and no excessive oil use AFAIK.

 

[unbreakable7132]

My engine is about 200 shy of 20k miles. I plan on a total tear down.New main bearings, re ring the pistons, hot tanked and totally cleaned. I'm having a friend at a radiator shop recore the radiator. I'm essentially rebuilding it all. As far as wear is concerned, I need to compile a list of measurements and specs and bust out the micrometers and calipers. I don't have a real baseline of what to expect of the tolerances and wear characteristics on these motors.But I can say however that my family has abused the bike(including myself) since we got it new in 81 and it seems like these 500's hold themselves together pretty well.

 

[richnct]

At 20k miles that engine should not be at all worn out. Unless you know of other problems, I would not tear it down beyond checking for damage related to the broken spring and valve/piston. Then make the decisions. If you go for a total rebuild, the cost will challenge the value of the bike I suspect. A replacement used engine is usually a better financial call. I probably have a head around that I'd give you some springs out of for the postage. Don't need a new spring, nothing else is in the engine is new. Email me at motorcycleguy DOT rich AT gmail DOT com I might have a whole head for inexpensive if you need that. We might have to compare years for compatibility. Keep the money in your wallet for now, one of the better features of these bikes is that they can be kept running for cheap



Never heard of a busted valve spring before, HTH fast did you rev it? I wind up mine just to hear them scream for joy.

 

[kureus]

My engine is about 200 shy of 20k miles. I plan on a total tear down.New main bearings, re ring the pistons, hot tanked and totally cleaned. I'm having a friend at a radiator shop recore the radiator. I'm essentially rebuilding it all. As far as wear is concerned, I need to compile a list of measurements and specs and bust out the micrometers and calipers. I don't have a real baseline of what to expect of the tolerances and wear characteristics on these motors.But I can say however that my family has abused the bike(including myself) since we got it new in 81 and it seems like these 500's hold themselves together pretty well.

I have four engines pretty much completely disassembled in my garage, and am doing a set of heads right now, so I have valve springs and valves all over the place. Let me know what you need and I will figure out how much it will cost to ship (never done this before). You will be helping me make use of what otherwise might be scrapped. I have other hard parts, all used to varying degrees but not badly worn.