Judge my CB550F2 1977 idling

[deltarider]

Not much to worry about. Owner's ride CB500/550s often at too low RPMs. Sparkplugs face the almost impossible task to stay clean over a wide range from 1000-9000 RPM. At prolonged idling plugs tend to foul. On highways I always choose the rpm where the mirrors become clear again. Around 5000 they vibrate and the view is blurred (this can't be helped). My CB500 engine was always happiest over 6000 rpm. Try it out for yourself.

[McCabe-Thiele (Ted)]

When I am out on my 400, the expresion ride it like you stole it springs to mind.
It's like a video game, going through the gears, keeping the revs up to be on song.

[alexdecker]

When I am out on my 400, the expresion ride it like you stole it springs to mind.
It's like a video game, going through the gears, keeping the revs up to be on song.

Interesting, I actually have a tendency to shift up all the time. For instance, shift up to 4th gear at around 60 km ph. I guess I should run 3rd gear a little longer then!

Do you have a set RPM you usually shift at?

[McCabe-Thiele (Ted)]

Not run my 500 in yet, on the 400, when in 3rd or above I like to see at least 6k revs on the clock on flat roads, on a uphill climb closer to 6500 depending on if it's feels under load. Here in the UK with 30 & 40 mph  limits everywhere I'm often in 3rd or 4th.

[K2-K6]

  "At prolonged idling plugs tend to foul."

This is a direct consequence of setting idle airscrew mixture incorrectly. As noted in a recent pdf "document " of advice.

Set properly, plug fouling is all but unherad of in experience. 

Advocating to run excessive fuelling when the throttle is closed has these results, along with bore wash and exhaust corrosion potential. 

[Oddjob]

Shift timing depends on conditions. Sometimes it's fine to shift at low revs, sometimes you like to amble along with low revs. The 500 is normally fine with that, if you need to pass something then shift down. Don't be fixated at only shifting at a set speed. Change when you want, listen to the engine.

[deltarider]

  "At prolonged idling plugs tend to foul."

This is a direct consequence of setting idle airscrew mixture incorrectly. As noted in a recent pdf "document " of advice.

It's been a problem at prolonged idling ever since the CB500 was on the market. It made Honda France change the advice on which sparkplugs to use. In continental Europe the NGK D8ES-L became the favourite after break-in period, being "auto-nettoyante" (selfcleaning). This concerned the CB500, but the 550s were hardly any better in spite of 1¹/₂ turn out for the air screws vs one turn for the CB500.

Set properly, plug fouling is all but unherad of in experience. 

Then we live in different words. Already in 1980 I was warned by mechanics in the Honda workshop. It was then new to me. I have followed their advice.

Advocating to run excessive fuelling when the throttle is closed has these results, along with bore wash and exhaust corrosion potential.

Bore wash?! Bore wash does not take place where I am, with my settings. They are almost spot on with 1¹/₁₆ on average. Bore wash?! My cylinders (143.000km) have not needed a rebore yet. Bore wash?! It was about sooted sparkplugs, not plugs dripping gasoline.
Besides, it doesn't need to be a problem at all, if people use their bike for the use Honda had in mind: just start  and ride. If you're more the tinkering type, then you will run in sooting the plugs AND depleting the battery.

[Johnwebley]

When I am out on my 400, the expresion ride it like you stole it springs to mind.
It's like a video game, going through the gears, keeping the revs up to be on song.

Interesting, I actually have a tendency to shift up all the time. For instance, shift up to 4th gear at around 60 km ph. I guess I should run 3rd gear a little longer then!

Do you have a set RPM you usually shift at?

On the open road, 7,000 rpm is ok for fast road work

8,500 for very fast road work

These should be done several times a ride

Sent from my SM-A546E using Tapatalk

[Oddjob]

Prolonged idling has never been advised by any manufacturer. It does happen, especially during servicing but a quick ride will clear up any problems generally. If Honda France was the only country to recommend changing grades of spark plugs you ever thought they did that because of what was in their fuel that wasn't in other countries?


Honda mechanics like most other mechanics have been known to give the wrong advice out deliberately. It depends on who they are talking to, if they dislike them or consider them either a nuisance or an idiot they'd tell them stuff that was clearly untrue. I've seen mechanics tell people that a Yamaha SR500 had points behind the rotor which ran in oil, so never needed changing. Of course it had CDI. Don't take what any mechanic says as gospel unless you know them well.

143,000 kms is barely run in. Do 263,000 miles on a set of barrels with no rebore and then you can brag. It needs one now, it's very tired these days. Bore wash is a known problem, especially as the bikes age and float levels alter as wear occurs for instance.

[Bryanj]

Bore wash blew 1 cylinder on an Essex 3.0 V6 when the acc pump diaphram holed, and i mean destroyed the piston.

PLUS i have bored a few 500/550 cylinders recently and about 75% of these, whilst looking perfect, were actually "barrelled" in use

[K2-K6]

They probably needed "special " spark plugs because they didn't take notice of Honda's advice in how to set mixture correctly 

[alexdecker]

Damn 143000 km. I think mine have gone around 83000. I actually thought that was in the higher end, and maybe the engine was reaching its end. I did a big engine job three years back, changing the shells on the crankshaft and rods, new sealings, new primary chain, top end rebuild, honing, new piston+rings etc.

How much life is normal to get out of these bikes?

- Alex

[Bryanj]

The problem there is the honing, Honda tolerances are so tight that honing can put clearances out of spec

[Oddjob]

I have 2 500s. The K reg is the 263000 one, no bore, same clutch. It’s had a few sets of rings, a few chains but that’s about it. The L reg one is the one I’m restoring right now, that’s done around 167,000 miles. No bore, one set of rings, new shells, both chains, new bearings but same clutch and gearbox. That still sounds like a brand new bike, great compression.

Change the oil regularly is one of the things that help them last and last. I have a nos set of barrels for this engine off a 550 but I may not use those if the present barrels are still ok.

I’m like Bryan and don’t advise honing anymore. Unless you have them under bored and hone them out to get a really tight clearance.

[deltarider]

They probably needed "special " spark plugs because they didn't take notice of Honda's advice in how to set mixture correctly 

Are you really, after been able to learn my detailed report, trying to still advocate that ridiculous method by AMERICAN Honda? The same ltd, co. that has managed to never miss an opportunity to mess up, especially data regarding the CB500? What is your opinion then on p.165 in Shop Manual Honda CB500-550? Doesn't that say 022A over the left column? Ever heard of a CB500 with 022A carbs? CB550 had them, CB500 didn't.
But I'll be a sport, why don't you show us a video where you practice what you preach? I'd love to see you doing it.
@Oddjob, what's keeping you from surprising us with a vid demonstrating that you really can manage to have a CB500 idle nicely @ 600 RPM. I'd love to learn that.