SOHC.co.uk Forums > CB500/550

Judge my CB550F2 1977 idling

<< < (11/14) > >>

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:

--- Quote from: K2-K6 on August 17, 2026, 12:28:38 PM ---  "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.
--- End quote ---
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.

--- Quote from: K2-K6 on August 17, 2026, 12:28:38 PM ---Set properly, plug fouling is all but unherad of in experience. 

--- End quote ---
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.

--- Quote from: K2-K6 on August 17, 2026, 12:28:38 PM ---Advocating to run excessive fuelling when the throttle is closed has these results, along with bore wash and exhaust corrosion potential.

--- End quote ---
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:

--- Quote from: alexdecker on August 17, 2026, 11:29:19 AM ---
--- Quote from: McCabe-Thiele (Ted) on August 17, 2026, 10:09:51 AM ---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.

--- End quote ---

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?

--- End quote ---
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

Navigation

[0] Message Index

[#] Next page

[*] Previous page