My RC24 resurrection

For $20 I installed a volt meter on the 400 because I was having reg/rec issues (killed a brand new Shorai on one ride). I feel more comfortable just eyeballing the gauge every now and then to see the bike is working as intended. It is a nice piece of mind once you get a good reg/rec in there.

 

Oh yeah, I forgot to mention I didn't take the time to make my mounting look pro. Take the time, then you won't have a janky wire hanging out. It is probably driving Capt crazy.

 

Was / is there supposed to be a pic?

 

^^ 14.4 on the triple

 

MOSFET installed and tested. Went for a 40 minute ride and it was charging nicely above idle at 14.4v. Only just above ambient temperature when my old reg/rec would have been very hot to the touch. I’ve bought a button voltmeter and switch, so will install that soon.



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Good deal man!!

 

Hi guys. Hope you’re all well? A little update from me.
Really happy with the mosfet upgrade. Deffo a bit more juice in the system, headlight is brighter and a good, steady charging voltage across the battery.

About 3 weeks ago, the bike cut out on me again. Have to say I was pretty close to just selling the bike or part exchanging it for something newer. I’d just had enough. After I calmed down, I contacted someone I knew in the Honda Owners’ Club who also owns a RC24, to get a recommendation for a mechanic who I knew had worked on his bike. I contacted the mechanic, who has years of experience renovating all sorts of motorcycles and I sent him a long, rambling email about the randomness of the cutting out issue, and whether it was something he could investigate. He sent me an email back almost straightaway with basically two lines, saying ‘change the ignition coils’. Back in the day, when I was renovating the bike I had been recommended to replace the coils by a couple of folks. I didn’t, but I did check their resistances and all seemed good so I reused them. However, two things. Firstly, coils can read the correct resistance when cold but start to break down as they get hot. Secondly, I discovered a few weeks ago that my multimeter has been giving false readings!!

So I’ve replaced all the coils. So far I’ve done 1000kms on the bike, since then, and all good. But to be honest, until it’s run trouble free for 9months or so, I’m not 100% sure. The mechanic also said it could be the cam sensors, so if it breaks down again, that will be the next, and last thing to replace.

One last thing. The engine has a slight ticking sound. I’ve done some internet research and it seems that this is relatively common on these early VFR motors? I found a thread on this forum about it, but at some point I want to see if I can get rid of it. Things to check seem to be a hole in the exhaust system / valve clearances. If any of you guys have any other thoughts on it, I’d be grateful for the advice.




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Great news. Keep on keepin on.

Regarding the ticking...

I built an 86 VFR700F a few years back. Had the engine sitting on a stand and went thru it, checking all cams and gear drives and setting the valve lash. NOT my first time doing this. Everything looked perfect. Completed the bike. Ran perfect, but had a persistent tick seemingly from the rear. This was a 23K engine. Didn't bother going back in, everything was spot on. Rode the fucker... HARD. Never changed or got worse.

The original idea of that bike was a track bike and it was built with an untitled frame. Well a few thousand miles of street and zero track I thought I should fix that. I had since sourced a titled frame and had another 13K mile 86 700cc engine. I completely went thru the 2nd engine and everything looked exactly like a 13K VFR engine should. Married the new engine with the new frame, layed on another wire harness and then transferred everything else over to make the transition pretty damn simple and easy. New exhaust gaskets used on both builds.

The new engine sounds EXACTLY like the first one. Couldn't fucking believe it. I have another 700, that while not silent, doesn't sound like either of those two engines at all. I have another 86 750 with over 50K that is the quietest of the lot. Another friends 87 700 sounds a little different than any of those. And another friends 86 700 has a sound all on its own too.

I decided I just don't fucking care anymore. They all have their own personality. I know the valves are set properly, there are no mechanical issues, they have good oil. I put my earplugs in (like I always do), and wring their fucking necks.

 

Captain, that’s good to hear. In all respects my engine seems absolutely normal. Throttle response is crisp, pulls really well, idles nicely, and other than this little tick, sounds fine. I’ll just have to learn to ignore it. TBH, can’t hear it above 9000 rpm anyway!


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If I combine my ignorance and my bad memory I reach the result that this ticking gave rise to the introduction of the components in the rectangle to the left of the drawing for '87 and newer RC24: https://images.cmsnl.com/img/partsl...skph-camshaftvalve_bigecl7g41e__0300_8830.gif

The first addendum, kindly provided by @50th VFR gives the section 24 of the Workshop Manual where these springs are introduced. Try to study https://u.pcloud.link/publink/show?code=XZDN5u0ZVcPjoeWh69J33hhRwA4190FWQ5j7 I did not nerd into this as it is irrelevant for my RC24 ('89) but it seems that they can actually be retrofitted on '86 by following the instructions. And having the required parts, of course



My guess is that the modified rocker arm guide and related spring provided more control over the seating of the adjuster screw and thereby reduces wear (and the mechanical noise relating to steel pieces being banged together and thereby giving rise to wear).

 

That’s really interesting, mate. Thank you.


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The issue of mechanical noise is very individual to bikes, designs and riders (and possibly even the helmet that you use).

I do believe that the valve mechanism on the RC24 engines is inherently noisier than the later engines that use the bucket-style adjusters. All my RC24s (2 bought new, 2 well-used) eventually sounded similar with a tappety sound from the top end and also some chatter from the gear drives. Both of my RC46's by comparison sound like the finely engineered machines that they are. If you worry about ticking sounds, don't even look at a Yamaha MT-10. Definitely a feature, not a bug! Just recite to yourself "they all do that" and ride on.

 

Had a 7Hundie that ticked and like Capt, everything was in basic spec (I am no master tech like some on here). My RC24 sounds mint down low, but a reed like sounds when running up the revs while riding. My VFR/RVF 400s have their own sounds with the same engine I believe. My Aprilia V4 sounds like rocks came with the oil pre-installed. lol
I put most of it in the catagory of WHATEVER and just keep riding them.

 

Or just ride a dry clutch Ducati.... after that nothing will sound rattily again!

Anyway, mine is an 1988/89 and it's still a bit tappy at tickover and always has been.

I did shoot a tiny bit of video when I got it running again after its long rest. Not much at tickover but you can hear it for a little bit.



One thing I will add is that I found balancing the carbs made the *clutch* rattle entirely go away. It may be something similar in that a minor imbalance between front/rear causes it to rattle.

 

Hey FastD, does your clock work? Mine seems like it changes, but I am also missing one row of black, so it isn't easy to read some of the digital numbers.

 

Couldn't you have just moved the VIN plate to the other frame? Or was VIN etched?

 

In addition to a metal VIN plate, it is stamped in the steering stem area of the frame, like every other Honda.

 

Whoops, forgot it's there also.

 

Yeah, mine works fine... I think a mouse had a nibble on the H at some point though!

 

...or at least *one* of the clocks I have works... The other one not so much.



On investigation it seems to be that the two conductive strips to the LCD itself have effectively lost their stick so it isn't conducting. Pushing on it and the numbers re-appear but I don't know how to permanently fix it.