Starter clutch problem

[Michael Sproston]

Looking for some advice guys. Bought a 1982 GS1100EZ about 2 months ago. Cleaned up the carbs and got it running good for about 2 weeks and then one day the starter turned but would not start. Pulled the left cover off and found the crank nut was loose and the rotor was spinning freely. Ah, must be the problem. Torqued it down, put it back together, and it did the same thing. Made sure the starter was good and after some research, and buying a rotor puller, took the starter clutch apart and found that everything looked normal. The three bolts holding the clutch to the rotor were good so I replaced the springs, pushers, and rollers in the starter clutch hoping this would cure the problem. Nope. The starter turns the intermediate gear which turns the large crank gear but it's not grabbing the crank for some reason. Very frustating as our riding weather slowly disappears. The only other thing I noticed was the inside of the rotor which gets pressed on the crank is a little chewed up from spinning freely before but when torqued on with the nut turns the crankshaft when spun by hand without any looseness. Any ideas? TIA

[posplayr]

You should be able to verify

the starter clutch operation even off the bike. If you reassemble it the gear will turn one way on the rotor and not the other way. You can do the same by simply removing the idler gear that is driven by the starter output gear. If you clutch spins both ways then there is too much clearance between the barrels and the outer hub of the drive gear.

If you used new barrels (which are 15.0 mm new if I recall) then the hub on the large gear is the next suspect. Again I think it should be approx 52 mm. I think if it is 51.5mm it will spin (ask me how I know). These dimensions for the small end (pre 83)and large end crank (later 83) rotors are the same.

Best bet is to buy a complete starter clutch from Flat out for about $95

Also when you re-assemble use blue Loctite on the allen screws and plenty of red loctite on the large rotor nut.

Also drop your pan and wipe out the metal dust that have been falling from your disintegrating clutch.

Posplayr

P.S. Oh and welcome aboard ; the welcoming committee should be along shortly

[Newbee]

Working on same issue

After much discussion via PM and phone calls(Thank you folks) I think we have determined that my problem is the hub on the large gear. My clutch appears to function correctly with spinning by hand but when starter engages it free wheels and doesn't grab the crank. I didn't measure anything but I can feel roughness and some grooving on the large gear. I feel that with a starter clutch repair kit and a new large gear my problem would be solved? Can't find a new gear anywhere. I am in the porcess of acquiring a complete used known good starter clutch and bolt it on and see if the symptom changes. I tried to find a complete starter clutch(new) from any source including FLATOUT and they are out of stock and back ordered. They had the cheapest price but it wasn't $95 it was $155 plus shipping..............

[posplayr]

Big v.s small end

I tried to find a complete starter clutch(new) from any source including FLATOUT and they are out of stock and back ordered. They had the cheapest price but it wasn't $95 it was $155 plus shipping..............

Ouch, the $95 is for the big end crank which I have bought two of recently. I wonder why the small end is 60% more???

Posplayr

[posplayr]

Cheap starter clutch and rotor

It is cheap but from the looks of it someone over did the torch and got the laminations for the magnets pretty hot.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=200252689678

Clutch might be OK, but who knows. Ask for some measurements

Posplayr

P.S. this is the small end rotor as it has the double roller bearings

[Carter Turk]

I just bought a complete starter clutch from Temecula Motorsport in California. It was about 130 bucks. Unfortunately they sent me the wrong large gear for my 1150 Katana. They claim it was the right one but it is not.

I needed the 35 mm ID and they sent me a 31mm. So I have a brand new 31mm ID large gear. Anyone want to trade for an unmolested 35mm?

I had scoring issues on the larger gear as well. All the rollers were worked over almost sharp on the edges. I spent about an hour polishing with 800-1200 sandpaper on the gear face that engages the rollers. I reinstalled it because I was getting nowhere with the guy at Temecula. I'll give him credit for trying to help, but the part is clearly the wrong one. In the Haynes manual they identify two different ID's with that gear. I have the bigger one with only one roller bearing.

If your starter clutch is ok I could sell you the gear, because I cant return it now. I don't know what a fair price would be though.

[Michael Sproston]

Thanks alot

I'll pursue the large starter gear as the problem - do some measurements and some sanding - see what happens and let you know. You guys rock!

[posplayr]

Polishing

I had scoring issues on the larger gear as well. All the rollers were worked over almost sharp on the edges. I spent about an hour polishing with 800-1200 sandpaper on the gear face that engages the rollers.

You need to be careful as take off too much. 800-1200 grit is pretty fine stuff but you only have 0.5 mm of total wear allowable on the Diameter of the gear face and the rollers (I called it a hub for lack of a better term).

Once the OD's wear down there is too mych space for the Sprage gear to lock ; at that point it doesnt matter how nice ans shinny the bearing face is.

I have seen two clutches now off of 1100's that have slight notching on the bearing face and they work fine. In gfact this probably helps the clutch work better as it gives it something to engage to.

Posplayr

[NICK!]

Michael, is the charging rotor spinning on the crank when you try and start it or is the big gear spinning by itself with out turning the rotor?

The problem you originally described (rotor spinning on the crank when you try and button start) was quite common on 1982 and before GS1100's. When they went to the big crank end most of that dissappeared.

What we use to do the first time it happened, if the rotor and crank end were still OK we would use valve grinding compound and lap the rotor onto the crank and then wipe off the compound and install the rotor. If the rotor persisted in coming off after lapping, we would lap it again and this time we would leave the valve grinding compound on the taper when installing the rotor. This fixed all but the most stubborn spinning rotors. In the case of this not working, we would lap the rotor, not clean off the grinding compound and mix more grinding compound with red loctite and put that on the taper and lap it as bit more and then install the rotor with that mixture left in place.

If that didn't work a new rotor and maybe a new left end was in order.

We had a lot of big bore street pounders in our neck of the woods back in the day. This was one of the common problems for the GS1100's. If it was a purpose built street drag bike we would drill the rivets out of the rotor, punch them through and seperate the rotor from the starter clutch housing and leave only the starter clutch but of course after that no more charging system.

If the big gear is spinning and not the rotor I would order a whole new starter clutch but off course there's no harm in what your doing now.

[Michael Sproston]

Thanks for the input NICK!

Big gear turns by itself only one way (clockwise when facing left side of bike) and rotor does not spin with it. Looks like I have to find a new starter clutch. I was having a hard time believing it was the clutch as I have already replaced the roller pieces and there isn't much else to the clutch itself.

[NICK!]

If your turning that by hand then it sounds like its working. If the rotor is installed on the crank and your standing facing the charging rotor and spin the big gear by hand it should only turn cockwise, you'd have to be awful strong to turn it counter clockwise as thats the direction of crank rotation and thats the direction the starter clutch should lock up.

Am I not understanding you?

[Carter Turk]

Posplayr, I don't know about the notchy rollers being a good thing. This is what caused the scoring on the gear face. My starter clutch snatches horribly almost everyday. This snatching finally destroyed my starter motor teeth.

I'm still toying with the idea of switching the wires on the handlebar switch so that the starter button turns the motor over without firing the coils, then hitting the run switch to light it off.

Rapid Ray here on this site suggested doing this with non stock high compression motors and may benefit the life span of a stock liter bike starter clutch as well.

[posplayr]

Notchy is slight

Posplayr, I don't know about the notchy rollers being a good thing.

I was referring to the outer face of the bearing surface (i.e. the big gear) that the rollers lock against. The one i took out of my GS1100ED was slightly notch and seemed to have zero ill effects. The diameters on both the "big gear" bearing face (52 mm) and the (roller) barrels (15 mm) need to be very close to those numbers.

I received another small end clutch that was nearly identical, and it was stated to be in good working order.

Were probably talking about 0.002-0.004" flatness around the perimeter. It is pretty slight and you only really confirm it by turning it in your hand ; you can hardly see it.

Posplayr

[Michael Sproston]

Starter rotation

NICK!, your previous post states that when facing the left side of the bike (rotor side) the crankshaft rotation to start and run the bike is counterclockwise (CCW). The large starter gear on the crank turns freely clockwise (CW) and locks up on the crank when turned CCW. When I engage the starter it's gear turns CW which turns the intermediate gear CCW which then turns the starter crank gear CW. Either you are incorrect on the crank rotation or my starter is turning the wrong way. I did take the starter apart and back together at first and then found the loose crankshaft nut so with that sequence of events is it possible that I somehow put the starter back together so it turns the wrong way? As simple as the starter is I don't see how that is possible but if that's the case I would feel like an idiot. Thank you for the info.

[posplayr]

I'm pretty sure

NICK!, your previous post states that when facing the left side of the bike (rotor side) the crankshaft rotation to start and run the bike is counterclockwise (CCW). The large starter gear on the crank turns freely clockwise (CW) and locks up on the crank when turned CCW.

I agree with all of this......

The rotor turns in the same direction as your wheels do under drive conditions (i.e. CCW when viewed from the left hand side).

When I engage the starter it's gear turns CW

I went and dug out a spare 750 starter I have. Jumper ed it across my car battery with booster cables. It also turns in the same direction as the rotor should (i.e. CCW).

Just for grins (and because I was fully isolated holding the starter in my hands) I reversed the booster cables on the starter and it still turned the same way (i.e. CCW). That kinda surprised me at first but it kinda makes sense as the commutator is switching the current in the armature so the orientation of external power doesn't make any difference.

That suggests you must have reversed the brush hookup locations , as that must determine the direction of spin.

This one is pretty amusing . I did my starter before, but it seemd the wires had a preference in length on how they should fit back together.

Good Luck.
Posplayr