CX500 GL500 650 Global

As the CX is unit construction i was wondering about extra protection for the cogs, would it cause harm to mix say Castrol 10W40 diesel mineral oil with a thicker 20W50 mineral oil in a 2-1 ratio? Or even two parts 10W40 to 1 part 75W90 gear oil which is similar to 10W40 engine oil? In theory the gear oil should provide better engine protection as it has a higher sheer resistance but are there any risks? Also noises, having read about the "guaranteed 40,000 mile water pump mech seal failure (especially with 25 years on top of it)" my 47,000 mile CX500B sometimes makes a very, very slight squealing noise. Is this the dreaded mech seal on it's way out? What other signs does it show for seal failure? Got some soluble oil (saw and machining coolant oil) from work, would this be safe to add to the engine coolant to lubricate the seal?

There's no harm in mixing oils so long as non of them have,"Friction Modifiers" which can cause the clutch to slip.There's no real need to though as these engines are not,"High spec" and are very robust.Many bikers here in the UK,myself included,use cheap supermarket 15w40 made for diesel car engine oil.It has a much higher sheer factor so is much better for the gearbox.Diesel engines have to tolerate much higher internal forces than petrol/gasoline engines hence it's better performance.

Note:I run a Citroen ZX Turbo Diesel car with over 250,000 miles on the engine but the oil and filter has been changed every 3,000 miles

I wouldn't mix fully synthetic oils with mineral oils though as I don't think there's been any studies on what affect it may have.

There are some myths and misinformation about these bikes/engines that have become folklore by repetition like Chinese Whispers.

1:The early cam chain problem was fixed within the first couple years of production/sale.More engines have been destroyed by ignorance and neglect and a failure to change oil and adjust the cam chain at regular intervals causing engine failure not because of any inherent weakness in the cam-chain system.

2:The mechanical seals often fail after the bikes have been bought after the bikes have been abandoned for years and,like any engine,all the seals dry out though lack of use.Again there's no inherent weakness in the system.If there were then millions of irrigation pumps around the world would be breaking down all the time as the seal is used in them.

See this thread at 140,000 Km.No mention of pump seal being replaced,
viewtopic.php?f=20&t=289

Don't worry about adding anything to affect the Water pump seals.

3:These engines do NOT start up on just one cylinder if the Carbs/Ignition and compression are nominal and the bike is in regular use.The two most common causes of bad starting on these bikes is none serviced carbs and none serviced starter motors.All covered in this forum.


HTH

Note:I do use an engine additive called,"Molyslip" and have been using it on my vehicles for or 30 years,

http://tinyurl.com/yct6mpo

Cheers, will have to try a blend. Start out with 10W40 diesel blended 3 to 1 part 20W50 or a gearbox oil if i'm feeling brave to notch the viscosity up a tad, all mineral though as i've heard mineral and synthetic is a bad idea. Will give the cam chain an adjustment next time i get the tank off to check the coolant, can't drain my tank yet as all my petrol cans are full of 97 octane Shell V-power stocked up before the price rise, only the best for my CX! Starts and runs like a dream, though i will have to have another look at my valves when i do the cam chain, bit noisy on right cylinder (that's what you get from using your dad's feeler guages that look to have been in use since the industrial revolution!) so i erred on the loose side. read about a drain hole in the chamber between the camshaft oil seal and water pump mech seal, the manual is'nt very specific on this but if the seal goes does the water drain into the oil which would show up as mayo (thankfully none in mine) or outside the engine as a puddle on the floor? only thing on the floor under mine is WD40 which i soak the engine in weekly! Fibreglassed up my rotten seat pan and she's ready to go, my test can't come soon enough!

When the Water pump side of the seal assembly goes it gives you a warning by a seepage from the weep hole which is located underneath the Water pump on the left hand side.You can see it with an inspection mirror or the like but I wouldn't worry about it.Just get a bit of thin wire and poke it through to make sure it's clear.



If the O-ring seal in the rear case of the engine goes you will get,"Milk" in the oil as the coolant will contaminate the oil same as if a head gasket goes between the coolant jacket and Cylinder head.