Engine overheating

[jackstraw]

1982 CBX-C, 25k miles, oil/filter change 500 miles ago, local temperature 20-25C

I bought my bike 3 months ago. and ride mainly on UK country roads 5-7k rpm in 3rd and 4th

On each and every journey when I set off the engine is smooth, pulls nicely and I can select neutral at will. After about 20 minutes neutral becomes more difficult to find and by 60 minutes or if there is any stop/start town riding getting into neutral is nigh on impossible. Towards the end of the ride the engine is no longer smooth and especially in town will not tick over

My thinking is that the oil is overheating and my remedy is either to fit a 10 row oil cooler or a larger oil reservoir underpan

Would you agree? If not what would you suggest, if so any help sourcing either would be appreciated

Thanks

[daves79x]

7K in 4th gear is well over 100mph. Are you traveling 'country roads' that fast? However, at those speeds, the engine should be getting quite enough cooling air flow. Is this new since the oil change? Are you sure you didn't dislodge one or both of the rubber grommets on the oil filter when changing? Something that might alter normal oil flow through the engine and cooler? Now, if this only becomes an issue when you hit the stop and go traffic - that WILL over heat the engine quite quickly. You may or may have not read here about our countless admonitions about avoiding stop and go riding at all costs. These bikes overheat quickly and repeated cycles of overheating takes the temper out of the piston rings and kills all internal rubber parts. It's no good. Perhaps do another oil change, taking great care that the oil filter is correctly installed (with the thrust washer on the spring), dropping the sump cover to see what's in there, making sure the screen is clear.

Dave

[CBX-tras]

Another thing to consider is replacing the oil cooler hoses. They can and do breakdown with age and disintegrate internally.

I would drop the oil pan, clean or replace the pickup screen, replace the cooler hoses and flush the cooler to be certain that there aren't any blockages.

A deep sump extension will provide an extra quart (liter) of oil capacity. (Can't hurt).

And never use any synthetic or semi-synthetic oil. This is, unless you feel like tearing deep into the cases to repair the starter one-way clutch mechanism.

[jackstraw]

Hi Dave
We have some great country roads but not quite that quick, we do get over 100mph at times but the average would be closer to 50-70mph - a mix of 2nd 3rd and 4th
Back in 1985 I rode my first CBX-B as a despatch rider delivering parcels in and out of central London, I'm guessing the lead in fuel in those days made a difference but overheating wasn't an issue.
Oil/fiilter change was done before I rode the bike out of my garage - very confident that oil filter was correctly installed.
I will drop the sump cover and check the screen is clear
Thanks
Jack

[jackstraw]

Another thing to consider is replacing the oil cooler hoses. They can and do breakdown with age and disintegrate internally.

I would drop the oil pan, clean or replace the pickup screen, replace the cooler hoses and flush the cooler to be certain that there aren't any blockages.

A deep sump extension will provide an extra quart (liter) of oil capacity. (Can't hurt).

And never use any synthetic or semi-synthetic oil. This is, unless you feel like tearing deep into the cases to repair the starter one-way clutch mechanism.

Hi CBX-tras
Points all noted, will do as you suggest. Do you know where I can source replacement oil hoses?

The UK supplier of classic Honda parts 'David Silver' recommended Motorex semi-synthetic for CBX's see photo.
Have you found CBX's run better on non-synthetic oil?

Appreciate your advice
Jack

[JoeInTUS]

You might want to consider installing an oil temperature gauge.

https://www.cbxclub.com/forum/viewtopi ... Vdo#p96383

[JoeInTUS]

SuperSportShed rebuilds oil lines in the UK although they are currently listed as out of stock. You might want to call them
https://thesupersportshed.com/product/ ... rrency=USD

Forum member Tevan rebuilds oil lines in the US and might be able to help you if SuperSportShed cannot.

https://www.cbxclub.com/forum/viewtopi ... =5&t=11744

[CBX-tras]

I make my own lines using Gates automotive transmission oil cooler hose in 1/2" size, clamp with a Oetiker, stainless pinch clamp. There only 15 PSI in those lines. My local auto parts store has the hose in stock, yours may also.

Unlike newer bikes the CBX one-way starter clutch has just 3 rollers to engage the mechanism. ANY synthetic oil is too slippery for the mechanism to function without slipping. Stay with your favorite dinosaur oil to avoid potential damage.

[jackstraw]

Unlike newer bikes the CBX one-way starter clutch has just 3 rollers to engage the mechanism. ANY synthetic oil is too slippery for the mechanism to function without slipping. Stay with your favorite dinosaur oil to avoid potential damage.

I always appreciate an explanation as to why I should do something rather than just being told 'its for the best'. Thanks for taking the time to add your comments and advice