Hot at the solenoid.

[Guest]

Back on the Kat project finally and attempting to fire up for the first time in 2 years tonight. The battery in the bike is about 4 seasons old but still will take a charge. It does discharge very quickly, however, so to aid starting I add on a full size deep cycle marine battery for extra oomph.

Generally, this spins the bike right over and it fires quickly. Not so this time, it seemed to labour a lot but finally did catch and run for perhaps 2 minutes on choke. When I removed the "booster" battery the bike died. Not a big deal but smoke from burning insulation on the lead from the battery to the solenoid caught my attention. The post was seriously hot.

Now I know the bike battery is on its last legs but does this in anyway explain the sizzling heat at the solenoid?

Being out of the practice of wrenching I'm a bit fuzzy right now so any clarification from the electrical gurus would be appreciated.

The solenoid too looks a bit iffy but before I change it or the battery I'd like some thoughts please.

Cheers all,
spyug

[maddog]

Cheers Spyug Sounds like a lot of amperage traveling thru the cable from battery to solenoid.. as far as the disconnect and die routine,not sure ,but possibly a failed/shorted battery and therefore not enough voltage to run the system after the disconnection? (of the aux battery)

[sk843143]

sounds to me like you have a ton of amps running through that solenoid. that means one of two things .... eather a short.... or something is binding up the starter.... my bike just did this and after checking all the starter cables and found no shorts..... and doing voltage drop tests,,,, i took the starter out to inspect the armature and look for internal shorts,,, what i found was that two of the magnets atached to the starter body had come loose and was rubbing the armiture.... after cleaning the whole starter, ( the mags had chipped ) regluing the mags i reinstalled the starter and it all worked perfictly

[Steve]

If you were using the starter a lot, sure, the solenoid would be a bit warm.

Take a good look at your jumper cable clamps to see how much contact area there is when they are used. Usually, they meet up with the post on only a couple of small points. Then you force about 50 amps or more through those little points while cranking the starter. Yeah, they are going to heat up.

.

[spyug]

Thank you once again gentlemen. All good thoughts. I'm tending to think Steve's idea is likely what I'm up against. I was finding it very difficult to get a good grab with the full size clips of the jumper cables and they did fall off a time or two.

I think I will try and fab up "L" shaped posts that I can bolt to the battery terminals and clip the jumper cable to.

I let you know how that works.

Cheers & thanks again.
Spyug

[spyug]

Well I tried again tonight with the booster battery but using "L" posts to the battery. Still smoke at the solenoid.

Changing the battery to the newer one from the 750 and I still get smoke. UNhook the booster battery and the newer battery gets it to fire so I call the old battery junk. Turning it over on the bike battery alone I still get smoking at the solenoid.

Do I have an issue with the solenoid? I'm thinking I likely do so I will change it out for a more modern one and see where that leads me.

I'm hoping I can get it running again smoothly by the weekend as I would like to try for a road test once again.

Cheers,
Spyug

[sk843143]

An electric moter draws the most current whenit starts spinning (actualy just before) if the armature is binding it will draw all the amps itcan from the battery....(mc batt cant produce a ton) when u use thejumpers the other batt can give the starter enough amps to start it spinning then the amps drop......you have some thing using a lot of amps.....take that starter apart and check it....its not that hard....i did mine in maaby 2hours start to finish.......

[spyug]

Thanks. So we are thinking buggered starter motor?

I haven't been inside one for many a year and haven't ever looked at a bike one but I'm assuming I'll need to clean the armature and maybe replace brushes. Where can you get those? Are there rebuild kits for them?

I do have a spare starter so I could try a swap out I guess.

Cheers all,
spyug

[koolaid_kid]

Just an educated guess on my part:
Your solenoid is functioning correctly but drawing an excess amount of current (measured in Amps).
The only place that current should be going (assuming good, clean connections) is to the starter.
The starter is designed to draw about 50 Amps of current, and the solenoid is designed to handle that efficiently.
Therefore, something in the starter circuit is drawing too much current. In order to "smoke" the solenoid, there would almost have to be a direct short in the circuit from the solenoid on. I suggest something inside the starter is shorted out, and I believe changing it out would be an excellent next step.

[spyug]

Thanks KK. I appreciate your insight and will make that my next move.

Cheers,
Spyug

[sk843143]

Yea..... I would see take the old one apart clean out up.the brushes on mine were fine just dirty. The magnets (poles ) had come loose and was rubbing the armiture (causing a bind)witch is another way the starter can draw more amps. Mine was saveable just some cleaning and gluing the 2 out of 4 magnets back in place . Starter comes apart with 2 screws. Try it on ur spare

[duaneage]

Dirty or worn contacts INSIDE the solenoid will cause it to heat the terminals and the body of the solenoid. Try a new solenoid.

[spyug]

Dirty or worn contacts INSIDE the solenoid will cause it to heat the terminals and the body of the solenoid

Now that is what I thought at first but wouldn't both terminals show heat as you mention. In this case only the terminal to the starter lead is heating up so that points back to the starter motor does it not? I have a new solenoid that I could try. If I get the same result then its for sure the starter no?

Time to wrench.

Thanks for all the thoughts guys. I'll report back when I find the culpret.

Cheers,
spyug

[duaneage]

Now that is what I thought at first but wouldn't both terminals show heat as you mention. In this case only the terminal to the starter lead is heating up so that points back to the starter motor does it not? I have a new solenoid that I could try. If I get the same result then its for sure the starter no?

Time to wrench.

Thanks for all the thoughts guys. I'll report back when I find the culpret.

Cheers,
spyug

The solenoid is easy to get to and cheap to replace. Being a sealed unit we don't know what is goin on inside. Check the crimped connection on the large wire feeding it, and remove any rust or scale from the nuts on the post. Dirt and rust = heat generation since it adds resistance. You have a large current draw on one end, a huge source of power on the other and in between wire and connectors that need to be as close to zero ohms as possible.

[spyug]

Thanks Duaneage. I will swap out the solenoid first. The one in the bike is the original and while I cleaned up all the posts and the contacts, as you say, who knows what's going on inside. I have seen solenoids go crappy so this could be the case again.

I'll wrench on that first.

Thanks bud.

spyug