Bike doesnt like to start in the wet

[bpw]

Hi

So its been raining for about 10 days strait here in California and the bike has been quite cranky about starting (it lives outside).  Seems the left cylinder is reluctant to get going in the morning.  Starts right up in the dry so I dont think it is temperture related (hasnt been very cold either just wet)  Choke looks to be working evenly on both carbs.  I remember reading somewhere about something in the ignition system that can get picky in the wet when it is getting old but forgot what it was (coils maybe).

Once the bike starts in the morning it does okay for the rest of the day, though still starts a little harder then normal.

Runs fine once warmed up, valves where recently checked and carbs balanced.

Since the weather has been so crummy I havent done much trouble shooting yet.

Any ideas?

Thanks
Ben

[Bob_Roller]

If you have the original grey plastic cased ignition coil, it may be cracked and moisture is getting into it, or it may have low resistence, or the insulation inside broken down .

How old are the ignition leads ?

Any corrosion where the leads attach to the coil, or spark plugs ?

[bpw]

Thats what I was trying to remember, Ill check tommorow, its way too nasty outside right now. Any way to check for low resistence?  

Leads are in good shape, dont think they are too old but Ill take a closer look at them.  

When I did my carb balance I was getting good fat sparks but that was in dry weather.  (screwdriver shorting method)

Thanks
Ben

[Bob_Roller]

To check for low resistance, you need to connect a multimeter to the low voltage, or primary circuit.

A normal coil should have 1.5 ohms for the bikes equipped with the OEM electronic ignition.

I had problems starting my '81 R65 below 55 F., when I finally checked the coil with a calibrated meter, I found it had .5 ohms on the primary windings.

Replaced the OEM coil with a Dyna 'Brown' coil, and the hard starting went away and hasn't been back in 2 years.

[Rob Valdez 79 R65]

I hate to sound like a broken record, but if it isn't the coil (although highly suspect, if original), then I have to ask, do you have the spark plug caps with the metal shield on them?  That is what originally came on my '79, and I tried to keep it original, but not riding in the rain forced me to NGK caps...

The following is kind of a trademark posting with me:



http://www.mikesxs.com/mikesxs-electrical.php?category_id=2.1

Scroll down.

I like the 5K cap on my points ignition (Part #23-3113).  I have been using them for about 15 years now (renewed every 2nd or 3rd year cause they are cheap).

He also has wire you need, in slightly longer than needed length.  

$11 plus shipping for all.

If and when you replace your wires, check the ends that come out of the coils.  If they are SOLDERED ON, that is good.  DO NOT THROW THEM AWAY!  You can use your soldering gun and pliers to remove them to use for your new wires.  They are much superior to the crimp-on type connectors.  Also save the rubber boots that cover the coil end of the wires.  I suppose auto parts stores would have them?

[bpw]

I do have the original metal caps, would the 81 on elec  ignition use the same ngk caps?  For that price it seems worth swapping out.  Been thinking I am going to switch to a dyna coil even if thats not the problem just to prevent future trouble.  The bike is my only transport and I do a lot of long trips with it.  seems like cheap insurance for less then a $100 for a coil and new wires/caps.

 What causes the trouble with the metal caps, is it just the design or do they wear out?

ben

[Rob Valdez 79 R65]

I don't know the flaw in the caps, myself.  I only know that when I switched, I no longer had wet-weather running issues.

Since you have electronic ignition, you will want to make sure you have resistance in either the caps or the plugs, themselves.  

The NGK caps I use for my points ignition are the 5K version.  I should be using the lower resistance, but I like the caps that push onto the threaded contact, rather than the rounded one.  That is just a subjective decision on my part.  It runs fine.



On another front, you may want to renew the heatsink compound on your ICU, if you haven't already.
That is more likely to fail when it gets hot, though.

[Bill Conquest]

What would be the best replacement for the original coils on a '79 R65 be? Mine are old & should be changed..saw the stock ones on the mikesxs site you recomend, Rob.. how about wires & caps?
thanks, bill conquest

[Bob_Roller]

Motorrad Elektrik has the latest Bosch coils for points type ignition, they used to be called the 'blue' coils, but now they are just silver I think the price was about $70 for two, plus shipping.

I don't know what type of automoive parts stores you have there in Hawaii, but NAPA auto parts on the mainland at least, does a pretty good job of getting these ignition lead parts.

 The after market manufacturer is called Belden, you may try a search to see what you come up with.

[Bill Conquest]

Thanks Bob - We do have Napa here but it's never a good deal.. what about the dyna brown coils i've heard about? Are they better?
Thanks, bill conquest

[Bob_Roller]

I installed a Dyna 'brown' coil 1.5 ohm dual output , on my '81 with factory electronic ignition about two years ago.

So as far what kind of service life I'll get out of it I don't know, but is was about $70 cheaper that the OEM dual output coil.

Motorrad Elektrik has the Dyna 'green' coil for points ignition, but you have to make a mounting point for it, as the dual coil setup for points ignition won't work.

[Bill Conquest]

Yah, just talked to Rich at Motorrad, great guy, & he suggested some checks to make before ordering new coils - my bike suddenly quit last night, I checked for fuel & that was o.k., then spark & there was none... after taking off the tank & touching around, it fired up & got me home. Will investigate more but instantly thought it could be the coils - Rich says maybe condenser, but will eliminate wiring first..Any suggestions would be welcomed!!
Thanks, bill conquest

[Semper Gumby]

Motorrad Elektrik has the latest Bosch coils for points type ignition, they used to be called the 'blue' coils, but now they are just silver I think the price was about $70 for two, plus shipping.

I don't know what type of automoive parts stores you have there in Hawaii, but NAPA auto parts on the mainland at least, does a pretty good job of getting these ignition lead parts.

 The after market manufacturer is called Belden, you may try a search to see what you come up with.

Hey, I've got a set of Bosch Blue on the shelf that I can let you have for a lot less than 70.  PM me if your interested.

Bill

[bpw]

After doing some research it appears the harley-davidson coils ending in -83A will work on the airheads.  They are a little higher resistance but it doesnt seem to be causing people trouble.  I just picked on up on ebay for $12 including shipping and will report back when I get it installed.

also it was dry today and the bike started right up.  Havent bothered testing my coil since the harley one was so cheap and I want it as a spare any ways.

Ben

[Rob Valdez 79 R65]

I have heard about the Harley coil favorably many times.  The same for a K100 coil.

I am not sure about the coil on Mikes XS, Bill Conquest.  I have only bought my caps and wires from him.

I bought a couple of Bosch Blue right before they became unavailable!  I am sure the silver ones will be fine.  Much better than the originals, that is for sure.