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04-03-2007, 7:43 PM LarryC Joined on 02-20-2007 Miami, OK Posts 13 Doing the water pump, cam chain and stator I am getting ready to replace the water pump seals, stator and cam chain and tensioner on a 78 cx500.  I have the rear cover off and am ready to order the following parts.  Is there anything else I should order while in there? Oil seal(behind water pump) 91202-283-013 O-Ring 94608-50000 2 each Gasket, Rear Cover  11394-449-306 Dowel Pin(Rear Cover) 94301-10160  2 each Cap, Valve Adj(not in very good shape) 12361-300-000 Oil Seal(Rear Cover) 91251-zw5-003 Tensioner, Cam Chain 14500-470-751 Guide Set, Cam Chain  14600-415-305 Spring, Tensioner  14515-415-000 O-Ring(6.5x3.1)  91312-415-000 Cam Chain  14401-ma1-013 Water Pump Cover Gasket  11396-415-000 Washer 6MM  90441-706-000 Washer 10MM  90453-415-000 Seal, Mech  19217-611-000 These part numbers are off Service Honda's Fiche. Thanks for your help.  I am really enjoying this site.  This bike only has 17k on the clock, and has been pulled apart about 3 years ago.  Everything looks real good.  My brother bought the bike and the stator went out.  I later swapped a 78 GL1000 for this bike and another 80 CX500.  I later sold the 80 and am now working on getting the 78 back on the road as a backup for my 76 GL1000. Larry 78 CX500 76 GL1000    Report

04-03-2007, 7:52 PM DickInRaleigh Joined on 02-26-2006 5405 Thornhill Ct Posts 469 Re: Doing the water pump, cam chain and stator Yes but go to http://www.servicehonda.com/ or http://www.ronayers.com/index.cfm for petter prices. Also use Yamaha p/n 11H-12438-10-00 for the water pump seal. ($12) The seal will be difficult to install without the tool but it can be done. I clean the bore out and give the leading edge a 45 degree chamfer to help get he seal started. Dick In Raleigh <><    Report

04-04-2007, 3:11 PM LarryC Joined on 02-20-2007 Miami, OK Posts 13 Re: Doing the water pump, cam chain and stator www.servicehonda.com is where I got all the part number info.  I will check out the Yamaha seal.  I need to see if I have a 27mm or 28mm bore.  It is quite a bit cheaper. Larry Larry 78 CX500 76 GL1000    Report

04-04-2007, 4:09 PM DaveNearAtlanta Joined on 03-03-2006 Lawrenceville, GA Posts 500 Re: Doing the water pump, cam chain and stator You may want to consider replacing the front camshaft seal, p/n 91201-415-013 while it's easy to get to.  My GL500 had a leak here. My Web Site 1982 GL500 1983 GL650 This User ID is no longer used. DaveF is my new User ID.    Report

04-04-2007, 7:20 PM neilage66 Joined on 08-12-2006 Oregon, WI USA Posts 124 Re: Doing the water pump, cam chain and stator So...this is the notorious "triple-bypass" ? I've heard tell... Wish I had something to add besides:  Best of Luck to You.  Village of Oregon - USA 1980 Z1R (Zelda) 1981 GPz550 (Rufus) Motorbike Photos    Report

04-05-2007, 2:23 AM Shep Joined on 01-30-2007 UK.2x1980CX500A Posts 7,648 Re: Doing the water pump, cam chain and stator  neilage66 wrote: So...this is the notorious "triple-bypass" ? I've heard tell... Wish I had something to add besides:  Best of Luck to You.  Don't forget that the Main failing part of the Mech seal can be done,"In-Bike", http://www.geocities.com/sheppola/cx500/mechseal.aspx   My Music http://www.reverbnation.com/pauldouglas/ Join Just In Case :) http://globalcxglvtwins.hostingdelivered.com/ Id quot circumiret, circumveniat    Report

04-05-2007, 4:24 AM LarryC Joined on 02-20-2007 Miami, OK Posts 13 Re: Doing the water pump, cam chain and stator I already have it apart to do the stator.  Thanks, DaveNearAtlanta for the suggestion.  I have added it to my list.  I plan to order the parts this weekend.  I hope to do the work the weekend of the 13th, hopefully it'll be warmer then.  Back down in the 40's all this coming weekend. Larry Larry 78 CX500 76 GL1000    Report

04-06-2007, 3:38 PM LarryC Joined on 02-20-2007 Miami, OK Posts 13 Re: Doing the water pump, cam chain and stator One more question about this.  I got the stator out.  It's definitely shorted to ground.  What I'm worried about is the cdi pulser is a mess.  I looks intact as far as wiring and such, but it is really filthy and rusty.  It looks as if the gasket had been leaking for a good while.  That's probably what caused the stator to go.  The wiring harness was a mess also.  The cdi pulser is 71.93 at Service Honda.  How often do they fail?  Any idea of the probability of it being bad?  Leon says it ran fine as long as he had battery.  Thanks, Larry Larry 78 CX500 76 GL1000    Report

04-06-2007, 4:53 PM Shep Joined on 01-30-2007 UK.2x1980CX500A Posts 7,648 Re: Doing the water pump, cam chain and stator  LarryC wrote: One more question about this.  I got the stator out.  It's definitely shorted to ground.  What I'm worried about is the cdi pulser is a mess.  I looks intact as far as wiring and such, but it is really filthy and rusty.  It looks as if the gasket had been leaking for a good while.  That's probably what caused the stator to go.  The wiring harness was a mess also.  The cdi pulser is 71.93 at Service Honda.  How often do they fail?  Any idea of the probability of it being bad?  Leon says it ran fine as long as he had battery.  Thanks, Larry Can you be more specific?There are 2 pulsar blocks e.g left and right cylinder.I'm no expert in this area but they are AFAIK an encapsualted coil with or without a magnet contained.By this definition they must be very robust as they are electro-mechanical.As there are very few resources I know of that can get new ones you will have to take a chance with them but they are not known for failing even after 27 years.   My Music http://www.reverbnation.com/pauldouglas/ Join Just In Case :) http://globalcxglvtwins.hostingdelivered.com/ Id quot circumiret, circumveniat    Report

04-06-2007, 5:11 PM LarryC Joined on 02-20-2007 Miami, OK Posts 13 Re: Doing the water pump, cam chain and stator The part I'm talking about is the part that sits behind the stator, attaches with 2 screws to the outside of the rear cover.  Had the small cover with 5 bolts on the rear cover.  Part number 30300-415-005.  I just found out from Service Honda that it has been discontinued.  Hopefully I can clean up the one I have and it will work.  The parts your talked about I got with the replacement stator.  It all tests good.  Guess I'll have to hope it is good.  The bike ran good as long as he had a hot battery, so is probably ok.  I was ordering it to ensure all was good.  I'd hate to get it all back together and have to pull the engine.  Thanks, Larry Larry 78 CX500 76 GL1000    Report

04-06-2007, 5:57 PM Shep Joined on 01-30-2007 UK.2x1980CX500A Posts 7,648 Re: Doing the water pump, cam chain and stator You mean the Advance and retard Mechanism.I've seem next to no posts about these failing in the four years I've been running my CXs(Gls) so I reckon a clean up will do however I'm pretty good with the old searches so I'd get this just in case if you like, http://tinyurl.com/37af6b Cheap as chips/fries as we say over here and why not :)   My Music http://www.reverbnation.com/pauldouglas/ Join Just In Case :) http://globalcxglvtwins.hostingdelivered.com/ Id quot circumiret, circumveniat    Report

04-07-2007, 3:34 PM LarryC Joined on 02-20-2007 Miami, OK Posts 13 Re: Doing the water pump, cam chain and stator Thanks for the link.  I bought it.  I spent a good part of the day cleaning and scraping off old gaskets getting ready for the parts swap.  Sure be glad when they get here. Thanks again, Larry Larry 78 CX500 76 GL1000    Report

04-21-2007, 2:22 PM LarryC Joined on 02-20-2007 Miami, OK Posts 13 Re: Doing the water pump, cam chain and stator Well, all went very well until I tried to put the new water pump seal in.  It flat would not go.  It'll never go now.  I ruined the seal.  I am going to order a new seal and take it to a machine shop and have them put it in, reaming in out a little if they have to.  I tried heating the cover to 250 for an hour, freezing the seal, and tried pressing it in.  No luck.  Wish me luck on the next try.  The cam chain and all went very nicely.  I rotated the engine several times by hand after putting it on and all seems to be fine. Larry 78 CX500 76 GL1000    Report

04-21-2007, 2:45 PM Anonymous Re: Doing the water pump, cam chain and stator STOP!  Are you aware of the Yamaha seal?  They are less expensive than Honda and they press in easier. Part Number: 11H-12438-10-00 Description: SEAL, MECHANICAL Price: $10.06

04-21-2007, 6:09 PM Shep Joined on 01-30-2007 UK.2x1980CX500A Posts 7,648 Re: Doing the water pump, cam chain and stator I wish I had posted this link for you. http://www.geocities.com/sheppola/cx500/mechseal.aspx It would have saved you a lot of bother :(   My Music http://www.reverbnation.com/pauldouglas/ Join Just In Case :) http://globalcxglvtwins.hostingdelivered.com/ Id quot circumiret, circumveniat    Report

04-21-2007, 6:58 PM R80Dave Joined on 03-03-2006 Appleton, WI Posts 851 Re: Doing the water pump, cam chain and stator Are you sure you didn't get a 650 seal for a 500??? They can be a different size. David in Wisconsin    Report

04-22-2007, 4:17 PM DaveNearAtlanta Joined on 03-03-2006 Lawrenceville, GA Posts 500 Re: Doing the water pump, cam chain and stator A tip was passed on to me to use some threaded rod, washers and sockets.  See Motorcycle Preparation. It has worked well for me on several GL500's with no real problem.  I've only used the Honda seals. I think I remember hearing there are some minor differences in the seal opening sizes between various bikes, though.  Maybe someone with more information can jump in. My Web Site 1982 GL500 1983 GL650 This User ID is no longer used. DaveF is my new User ID.    Report

04-22-2007, 5:18 PM Shep Joined on 01-30-2007 UK.2x1980CX500A Posts 7,648 Re: Doing the water pump, cam chain and stator I'm either going to bring some clarity to this or more confusion.I have stripped for spares several CX engines.I have re-built several CX engines from the crank up.I don't believe that Honda EVER made the Water pump seal orifice anything but standard dimentions e.g they made the hole 1 size. What I do believe is that somewhere down-the-line someone used a,"Yamaha" seal that needed the hole opening.This has now become almost mythological and therefore been given creedance that has no value. Also.The Metal part of the Mechanical seal has not failed in any way in all of the engines I've stripped and or re-built.It is an,"Interference-fit" and by definition bonded at a molecular level as close as can be defined without actual melting of the two metals. I can say say without fear of contradiction that many people,myself included(Only once and lesson learnt) have tried to to replace the Mech seal the official way and suffered failure and frustration. There is absolutley no need to bother risking the ruining a Mech seal or the back crankcase by doing this. Just do this! http://www.geocities.com/sheppola/cx500/mechseal.aspx         My Music http://www.reverbnation.com/pauldouglas/ Join Just In Case :) http://globalcxglvtwins.hostingdelivered.com/ Id quot circumiret, circumveniat    Report

04-22-2007, 8:45 PM Len in PA Joined on 03-31-2006 Bristol, PA Posts 485 Re: Doing the water pump, cam chain and stator Dave, That is exactly the way I did it. Seal went right in. Also, if you don't mind, what make/model is that nifty tent you use? Thanx! Len in PA '82 GL500i...nearing 100,000 miles    Report

04-23-2007, 12:35 PM Don in Oz Joined on 03-10-2006 Melbourne, Australia Posts 546 Re: Doing the water pump, cam chain and stator Well, Shep, the bikes we got in Oz definitely had two different size water-pump seal orifices.   The earlier CX500 (Oz standard and Custom) with CDI - from 1978 to 1981 - had the smaller size hole (from memory 27.5mm), and this could be easily seen when looking through the "bore" in the rear casing after the oil seal and the mechanical seal are removed.    The oil seal for ALL CXes and GLs is a 28 mm outer diameter - and I mean ALL.   What you see looking down the "bore" is a small step (0.25mm), which is the 0.5mm difference in "bore" diameters. The later bikes in Oz - the 1982 CX500 standard, 1982 Custom, CX500EC Sport - had the 28 mm hole for the mechanical seal, and when you looked down the "bore" in the rear cover, there was NO step. For our bikes, this change in bore diameter for the mechanical seal also coincides EXACTLY with the change in Honda part number for the mechanical seal, and with the change from 1981 to 1982 models.   It also coincides with the change from manual camchain tensioner to automatic camchain tensioner on our models, and from CDI to transistorised ignition, although there is no logical reason for the "tie-up". I have yet to research the "bore" diameter for the GL500, as it is a half-way change of the above two alterations, and it occurred between the 1980 and 1981 productions.  I also have reason to shortly investigate the size of seal in the CX500 Turbo, as my good turbo has the dreaded weep-hole leak, and turbos are basically a 1981 model (by design), although they were only sold as a 1982 model. The above-documented differences clearly show why some people are having difficulty inserting a later-model mechanical seal into an earlier model's rear cover. I believe the Yamaha seal being bought by people is only made in one size, and that it is only suitable for the 28mm bore in the rear cover.    This does not preclude some previous owners having had the rear cover of an earlier model bored out to 28mm. Perhaps the best approach - if you HAVE to remove the metal tank, and totally replace the seal unit - is to remove it FIRST, measure the hole, and then order the replacement. Don. GL500I, CX500TC (2), CX500EC (2), 1982 CX500C. GL1000, 1976 CB550F, CT110 (2), XL125S (2), 1973 CB175K6. Kwaka Z250C1 (2). Suzuki GS450SX, DR250SJ, GS125ESD.    Report

04-23-2007, 2:00 PM Shep Joined on 01-30-2007 UK.2x1980CX500A Posts 7,648 Re: Doing the water pump, cam chain and stator Thanks for the clarification Don.I don't know if the customs were actually sold in the UK as most seem to be imports and there's not many about compared with the ZABs.     My Music http://www.reverbnation.com/pauldouglas/ Join Just In Case :) http://globalcxglvtwins.hostingdelivered.com/ Id quot circumiret, circumveniat    Report

04-24-2007, 11:53 PM Harold Joined on 12-28-2006 Beside Washademoak Lake, N.B. Canada Posts 851 Re: Doing the water pump, cam chain and stator Hi,  I am a fairly new to the CX world,  but from my reading here in the forums, would it not be good idea to have a look at the starter gears inside the engine and maybe replace the 3 starter clutch springs. I do not know how expensive they are to replace,,, but I have heard of  Murphey's Law.  It's just a thought,,, hopefully someone with more knowledge of these bikes than I have can address this. Maybe it should be called a Quadruple Bypass.  Regards,    Harold "People are more violently opposed to fur than leather because it's safer to harass rich women than biker gangs." 1978 CX500 1980 CX500 Custom 1981 CX500 Custom 1982 GL500 Silverwing 1975 XL-100 http://www.myspace.com/downwiththebutterfly    Report

04-25-2007, 9:26 AM R80Dave Joined on 03-03-2006 Appleton, WI Posts 851 Re: Doing the water pump, cam chain and stator Harold, It is rare that the starter clutch assembly is a problem on a 500 engine. 99% of the time it is a 650 issue. Sleep peacefully ... David in Wisconsin    Report

04-25-2007, 9:08 PM Harold Joined on 12-28-2006 Beside Washademoak Lake, N.B. Canada Posts 851 Re: Doing the water pump, cam chain and stator Thanks Dave ,    I knew there had to be a reason I didn't buy a 650 "People are more violently opposed to fur than leather because it's safer to harass rich women than biker gangs." 1978 CX500 1980 CX500 Custom 1981 CX500 Custom 1982 GL500 Silverwing 1975 XL-100 http://www.myspace.com/downwiththebutterfly    Report

04-26-2007, 8:50 AM R80Dave Joined on 03-03-2006 Appleton, WI Posts 851 Re: Doing the water pump, cam chain and stator There are benifits to the 650s even though there is nothing wrong with a 500. David in Wisconsin    Report

12-15-2007, 7:28 PM DaveNearAtlanta Joined on 03-03-2006 Lawrenceville, GA Posts 500 Different GL500 Mechanical Seal Sizes  Don in Oz wrote: Well, Shep, the bikes we got in Oz definitely had two different size water-pump seal orifices.   The earlier CX500 (Oz standard and Custom) with CDI - from 1978 to 1981 - had the smaller size hole (from memory 27.5mm), and this could be easily seen when looking through the "bore" in the rear casing after the oil seal and the mechanical seal are removed.    The oil seal for ALL CXes and GLs is a 28 mm outer diameter - and I mean ALL.   What you see looking down the "bore" is a small step (0.25mm), which is the 0.5mm difference in "bore" diameters. The later bikes in Oz - the 1982 CX500 standard, 1982 Custom, CX500EC Sport - had the 28 mm hole for the mechanical seal, and when you looked down the "bore" in the rear cover, there was NO step. For our bikes, this change in bore diameter for the mechanical seal also coincides EXACTLY with the change in Honda part number for the mechanical seal, and with the change from 1981 to 1982 models.   It also coincides with the change from manual camchain tensioner to automatic camchain tensioner on our models, and from CDI to transistorised ignition, although there is no logical reason for the "tie-up". I have yet to research the "bore" diameter for the GL500, as it is a half-way change of the above two alterations, and it occurred between the 1980 and 1981 productions.  I also have reason to shortly investigate the size of seal in the CX500 Turbo, as my good turbo has the dreaded weep-hole leak, and turbos are basically a 1981 model (by design), although they were only sold as a 1982 model. The above-documented differences clearly show why some people are having difficulty inserting a later-model mechanical seal into an earlier model's rear cover. I believe the Yamaha seal being bought by people is only made in one size, and that it is only suitable for the 28mm bore in the rear cover.    This does not preclude some previous owners having had the rear cover of an earlier model bored out to 28mm. Perhaps the best approach - if you HAVE to remove the metal tank, and totally replace the seal unit - is to remove it FIRST, measure the hole, and then order the replacement. I can now confirm there are (at least) two different mechanical seal bore sizes in the GL500. I've replaced several mechanical seals in 82 GL500's in the past few years and never had any problem pressing in a Honda replacement.  Today I attempted to do so with an 81 GL500, and there was absolutely no way the Honda replacement would fit.  In a side-by-side comparison, the old mechanical seal was verified to be slightly smaller than the Honda replacement.  In looking down the bore in the rear engine case, there was no step. The original metal cup was undamaged so I pressed it back in and used Shep's method to transplant the innards. My Web Site 1982 GL500 1983 GL650 This User ID is no longer used. DaveF is my new User ID.    Report

12-15-2007, 8:45 PM Randall-in-Mpls Joined on 07-06-2007 Minneapolis, MN Posts 2,630 Re: Different GL500 Mechanical Seal Sizes When I replaced mine this summer, the oil seal fit perfectly, but the OEM replacement mech seal wouldn't even begin to go in until I reamed the hole with a dremel flap wheel to create a step.  I bought the more expensive Honda seal assuming it would fit without modification.  I'll be helping with another mech seal replacement come spring.  What size is the Yamaha substitute? R '78 CX500 - Black Maggot --> Green Grub / Yellow Grub / Red Grub ???    Report

12-16-2007, 2:19 AM trev_h Joined on 09-11-2006 stafford, United Kingdom Posts 200 Re: Different GL500 Mechanical Seal Sizes Hi, The Yamaha seal is the same size as the larger of the 2 Honda seals. If you are not confident in pressing one in you can always swap the innards. It is impossible to tell with certain models what size is fitted till they are taken apart. Our only official Uk custom was the 81 Cb model which is when they started using the slightly larger seal and may have either size fitted , this situation was the same for the Gl's. The seal supplied by Davey pumps is also of the larger type. cx 650/500c special, 78 500z, 94 bmw k75rt    Report

12-16-2007, 9:09 AM Anonymous Re: Different GL500 Mechanical Seal Sizes I disagree. I mangled a OEM Honda seal trying to press it in. Went to a Yamaha dealer and got a seal and it pressed in without any problem and is still working fine. I consider myself fairly proficient as a mechanic and I must have needed the smaller diameter seal and unwittingly purchased the larger one first.

12-16-2007, 9:11 AM Phil in VT Joined on 03-02-2006 Lowgap,NC Posts 1,041 Re: Different GL500 Mechanical Seal Sizes That last was me. oops 06 Suzuki S 50 Boulevard Cruiser ANY WARM DAY ABOVE GROUND IS A GOOD ONE (unknown senior citizen) Springfield, VT    Report

12-17-2007, 12:27 PM Randall-in-Mpls Joined on 07-06-2007 Minneapolis, MN Posts 2,630 Re: Different GL500 Mechanical Seal Sizes The larger seal is what Service Honda sold me.  I assume the smaller seal is NLA. Fitting the larger won't be a problem.  I have the flap-wheel to enlarge the hole, and I made a press using a short piece of 1-1/2" PVC pipe, a section of threaded rod, and a couple large washers (both ideas from Rob Davis' page on the topic.)  Worked like a charm! R '78 CX500 - Black Maggot --> Green Grub / Yellow Grub / Red Grub ???    Report

12-17-2007, 12:40 PM Randall-in-Mpls Joined on 07-06-2007 Minneapolis, MN Posts 2,630 Re: Different GL500 Mechanical Seal Sizes  Phil in VT wrote: I mangled a OEM Honda seal trying to press it in. Mine began to warp a little.  That's when I changed tactics, and picked up the flap-wheel to ream the hole.  I worked in small amounts until the cup felt like it would fit, then it pressed right in, re-rounding the cup. I do have a very small drip, but I'm fairly certain that's from failing to anneal the copper crush washer on the impeller.  I plan to pull the pump cover and correct that in the spring. R '78 CX500 - Black Maggot --> Green Grub / Yellow Grub / Red Grub ???    Report

12-18-2007, 6:49 AM trev_h Joined on 09-11-2006 stafford, United Kingdom Posts 200 Re: Different GL500 Mechanical Seal Sizes Hi Phil. Maybe you are right, The honda seal I measured the Yamaha one against may have been the smaller type but the part no. listed it as a 650 seal. I have often wondered whether they had different suppliers of these seals and the spec was slightly different. All I know is that some go in really easy when others won't. I have 2 to tackle shortly but I will be trying the Davey type seal in them. cx 650/500c special, 78 500z, 94 bmw k75rt    Report

12-18-2007, 10:56 AM Phil in VT Joined on 03-02-2006 Lowgap,NC Posts 1,041 Re: Different GL500 Mechanical Seal Sizes Good luck and be sure to let us all know how it all turns out.  I think I am going to invest in some quality (read accurate, but pricey)  metric calipers. 06 Suzuki S 50 Boulevard Cruiser ANY WARM DAY ABOVE GROUND IS A GOOD ONE (unknown senior citizen) Springfield, VT    Report

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