Starter issue Mitusba SM-229 and SM-8210

[Guest]

I have this 83 GS1100gl and apparently have a starter issue(I hope). When I go to start the bike the starter may spin the engine quickly, sometimes it just stops spinning the motor over completely or it is very slow to crank. There seems to be no rhyme or reason to what it may do.

So that is the starting issue and this is what I have done to remedy the problem.
New battery fully charged
Solenoid tested ok
All connections looked good
Took engine start switch and run/off switch out and cleaned it all up
Took the starter up to the parts store and it is drawing 18 amps(no load) on their fancy alternator/starter tester and it spins great
Took the starter apart to check the brushes and commutator(brushes are like new, commutator was a little dirty. Polished it up with some 400 grit emery cloth)

By rights I shouldn't be having any problems. But what I noticed is that the starter I took out is a Mitsuba SM-229 which is a 500 watt, two brush starter. I happen to have an extra starter which is a Mitsuba SM-8210 600 watt, four brush starter(which is JUNK).

Now the SM-8210 has failed quite spectacularly and will not be getting rebuilt(not even close to being worth it) I was wondering if the 100 watts will even make that much of a difference?

I did look on Alpha Sports site it seems the SM-229 was an early design as where the SM-8210 was a later design(Thanks Tom203 for an early post that led me to that)

If anyone would love to give an opinion or steer me in the right direction it would be more than welcomed.
Thanks,
Paul G

[planetcaravan03]

I should also add that it seems to run the battery down fairly quickly.

[Grimly]

Wouldn't be surprised if there's a shorted winding or segment there.

[tom203]

You recently had petcock leaking problem- did your check crankcase to make sure it did not fill with some gasoline? The starter motor would have trouble turning the crankshaft thru a high oil/gas level.
Where are you getting these watt ratings on starters?

[JTGS850GL]

Starter wattage wont give you inconsistent cranking.

Do check your oil level to make sure it's not too high. What voltage do you measure at the starter motor when it's having trouble cranking?

[planetcaravan03]

Wouldn't be surprised if there's a shorted winding or segment there.

I checked the armature and got low, but consistent readings doing the 180 and bar to bar test. The commutator did not show any continuity between itself and the shaft.

You recently had petcock leaking problem- did your check crankcase to make sure it did not fill with some gasoline? The starter motor would have trouble turning the crankshaft thru a high oil/gas level.
Where are you getting these watt ratings on starters?

I changed the oil and filter(filled to 3.5qts) before I attempted to crank. I also pulled the plugs to make sure the cylinders were not full of gas as well. The wattage ratings are stamped on the mounting tab end of the starters. The SM-8210 says .6kw and the SM-229 says .5kw

Starter wattage wont give you inconsistent cranking.

Do check your oil level to make sure it's not too high. What voltage do you measure at the starter motor when it's having trouble cranking?

I will have to check the voltage in the morning.

[planetcaravan03]

I have finally sorted out the erratic starter issue. Turns out the positive battery cable had a small tear in the insulation(backside to my view) and it had corroded to less than 1/4 of the strands being a solid connection. But that is o.k. It was a cheap fix and now every single wire in that circuit has been checked and cleaned. Now if I could only get the carbs straight so it will idle or start without using starting fluid life will be grand.

[Steve]

Now if I could only get the carbs straight so it will idle or start without using starting fluid life will be grand.

Congrats on finding the problem.

Now, about the starting issue, ... the two prime areas to address are dirty carbs and tight valves. Check BassCliff's site or Nessism's signature for the ultimate carb cleaning guide. Also in BassCliff's site, you will find the valve adjustment tutorial. When you get those two items done, you will not be able to get your thumb off the starter button quick enough. It will almost seem that you just have to point at the button and the bike will start.

If you don't feel comfortable doing your carbs, there are a few of us that will do them for you. Valves will have to done by you, I am just a little too far away for a house call.

Let me know if you need any help.

.