Topic: Afraid of the rain! (Points question)

[1977_cb550k]

Hi,
I’ve got a group ride happening this weekend and there is a chance of rain.  Whenever I ride in the rain, my bike loses power and I’m pretty sure my points are getting wet.  I have a new’ish gasket on the points cover but it has a tiny split in it. 

Two questions:
1. Any tips on how I might seal up the points cover better? (Need a quick hack)
2. If I eventually move to a Dyna S will that fix the issue?

[bryanj]

A SMALL amount of silicone sealer and dyna can take a lot of power

[M 750K6]

I use the stock cork gasket on my 750, with a smear of grease on each side. Also holds it nicely in place when putting the cover on.

[1977_cb550k]

Grease - great idea, thanks.

[rotortiller]

I would look at coil, coil wires  and/or spark plug caps.

[HondaMan]

I would not recommend the Dyna for a 550. Or a 500.

Often, loss of spark in the wet comes from the sparkplug caps themselves. They may not be making a solid connection with the wires: if you still have the length, try trimming off 1/4" from each plug wire and then screw the plug caps back on to see if it helps.

Another thing that will cause this is: bad sparkplug caps. They have a limited lifetime, and the caps on coil 1-4 and on 2-3 must be within 500 ohms of each other, or both get weak spark. The one with the weaker spark will also have a darker sparkplug.

[1977_cb550k]

Thanks HondaMan, always appreciate your advice!

[Deltarider]

As far as reliability, plugcaps are the CB500/550 Achilles' heel. Back in the day you had aftermarket 10.000 km service sets (oil, filters, plugs, etc) that also included NGK plugcaps. The brand was Dino IIRC.
The only time in 44 years I didn't make it home without assistance, was in torrential rain. Happened the first year I owned my bike (1980). With some luck, caps may live some 15.000 km, but that's about it. Depends on riding conditions however.

[rotortiller]

As far as the SOHC caps go on the spark plugs they can carbon track. A temporary solution and common troubleshooting method is to take dielectric grease and coat the plastic cap exterior and interior then look for an improvement. You can do that same grease thing to the high tension wire exterior later if cap greasing shows nothing useful. It is easy to watch the external carbon tracking or shorting to ground at night and often it can be heard as external arching by young ears. The grease method also works on coil over plugs that are causing miss-fire on modern bikes due to degraded insulating properties. If the bike is dry you always have a squirt bottle with water to assist.

I have actually watched CDI spark arc down the white insulator from the plastic cap to the plug wrenching flats, different ignition but still quite impressive.

[HondaMan]

As far as the SOHC caps go on the spark plugs they can carbon track. A temporary solution and common troubleshooting method is to take dielectric grease and coat the plastic cap exterior and interior then look for an improvement. You can do that same grease thing to the high tension wire exterior later if cap greasing shows nothing useful. It is easy to watch the external carbon tracking or shorting to ground at night and often it can be heard as external arching by young ears. The grease method also works on coil over plugs that are causing miss-fire on modern bikes due to degraded insulating properties. If the bike is dry you always have a squirt bottle with water to assist.

I have actually watched CDI spark arc down the white insulator from the plastic cap to the plug wrenching flats, different ignition but still quite impressive.

Rotor: you remind me, that certain types of dirt can combine with grease (oil) on the plug caps and this becomes an outside-the-cap track, too. I'd forgotten all about that: it happened on a 750 with bad fork seals that had lightly coated the plug caps, and the dust stuck in the goo, and they would arc across the outside once in a while (in the dark was when we saw it). Wiping off his plug caps with a rag dipped in gas (from the tank) saved the trip the next day.

[MauiK3]

Hondaman, does your transistor points system work with the 550/500 bikes?

[HondaMan]

Hondaman, does your transistor points system work with the 550/500 bikes?

Oh, yeah.
It was originally designed FOR the CB500 (my own) in 1972.

This happened after someone brought in his CB500 with melted wiring from the alternator stator to the frame: he had installed both a 55/60w halogen headlight bulb and a Dyna S with 3-ohm coils on the previous weekend. It was a new design then: it has been modified (in 2006) to use modern transistors, shrink to  1/2 the size (2x4x1 inches now) and sense the points plate temperature to aid with cold running.

[MauiK3]

And folks, there you have it.
Good to know.

[dave500]

im with the dodgy spark caps,you should be able to ride in the rain easy.

[Oddjob]

TBH my experience with arcing in the rain were the leads themselves not the caps, they were so bad back in the 70s that I covered the leads with insulation tape to try and stop the arcing. That worked to some degree but the look wasn't the best.

I've since found reversing the coils helps much more, you can't just take them off and turn them round as the clamps won't fit but taking them off the clamps via the 2 screws and turning them round does work. A little fiddling to find which coil is best on which side can sometimes be needed due to lead length but fitting number 3 lead on number 2 cylinder makes no difference for example. This method works much better IMO because the rain isn't driven into the lead openings on the coil and those openings are not exactly sealed as I found out when replacing the leads on an old set of coils, the old leads just pull out really easily. It also helps in running the leads across the top of the engine instead of hanging them like spaghetti over the exhausts, you can use lead clamps on the head bolts etc to keep them in place and the heat of the engine helps keep them dry and thus safe from arcing. Since doing this I've never had any arcing problems.

A member on the UK forum devised a method of replacing the old coil leads with more modern ones, I'd certainly recommend trying that solution as the coils themselves seem indestructible, it's the leads themselves that deteriorate over time, change them and they appear good for another 50 years.   

[Rayzerman]

Aren't the wires permanently in the coils?  Is there a link to replacing them?  OTOH, not much can go wrong with copper wire.

How about heat shrink on the coil to wire interface, or heat shrink the entire wire?

[Oddjob]

Yes they are permanently attached, however as I said a member devised a method to get inside the coil body so you can cut them and resolder a new section of ht lead in its place. As times goes by the old ht leads start to crack and the internal core starts to suffer as well.

[Deltarider]

Actually it is the (road)dust your bike hits over the miles which is the culprit. Wires and caps become covered by silicates and the like. No prob in itself, but in rain it becomes conductive. That's why the problem can dissapear when the HT route is dry again... till the next shower. To keep it clean with whatever, will help, but over time build carbon tracks may demand replacement nonetheless. The prob is not difficult to diagnose, so spraying some WD-40 and wiping wires and caps will help you to continue your ride and arrive at your planned destination.

[HondaMan]

Another 'solution', though I suppose temporary, is the silicone sleeves found in some USA Speed Shops for the uber-high-voltage racing engines. It was required on dragster engines with super-high-voltage systems and those that run on the various volatile fuels like nitro or alcohol. This looks like a thick, flexible heatshrink tubing, comes on a roll, and slips over the normal sparkplug wire. I don't have a speed shop near here, though, since the dragstrip closed up 2 years ago, so I can't call them and ask about the name of the vendor? Maybe a 'net search could find some?

[1977_cb550k]

I ended up fitting a Dyna S and I LOVE IT. The bike runs so much better now, and cold starts are now very easy.  Wish I installed it years ago…

Haven’t ridden in heavy rain yet so we’ll see if my caps need replacing - but just did a 3-day 1,600km road trip and the Dyna worked a treat. Even hit a new high speed record on my bike. 

[Don R]

 DEI protect a boot covers the plug ends. It's more of a heat shield than water though.