Wont turn over on Starter Motor

[LTD Project]

Bike: GB’s ZX1100 A2 Unitrak

Ok so jobs done since it last fired up no issues.

Alternator cover over off, rotor and stator off and reseated, thread lock where it should be, everything cleaned and reassembled, obtained 95 ft/lb on rotor bolt by sticking a piece of wood through rear wheel and up against swing arm.
Was recommended on this site but is it possible to do damage to the internals using this method?

Front sprocket off and shift casing removed to turn the the drum plate one pin as neutral light was coming on between 2nd and 3rd rather than 1st and 2nd.
Got 60 ft/lb on front sprocket nut by using same method of wood in back wheel.

Anyway, all work done and tidied up, she wouldn’t turn over, starter doing nothing and just a single click sound from battery area when button pressed. Thought it might be a flat battery but now fully charged and same outcome.

Thought I would just check that engine turns over by removing timing cover and putting a socket on the end of the crank. She does rotate but one of the four compression strokes is quite tight! I wonder if it is too tight for the starter motor to turn over?

I should add that clutch is free and it moves easily from neutral to 1st and back to neutral.

Have I buggered something putting all that torque through the engine rather than using a proper tool?

All constructive comments welcome to troubleshoot/fix this as I am pretty much out of ideas.

Thanks

[Al]

Take the generator cover off and the starter idler pinion out. Check that the starter gear rotates freely in one direction only. If that is good turn the engine over from the timing side as before. If the tight spot has dissapeared then my guess would be that the stator has not sat down flat in the casing and is binding the rotor. Its easier to get it not flat than flat.
Its worth bearing in mind that at 95 ft/lbs you are putting 50% more torque through the crank than the motor makes. The correct figure for the bolt is 116 f/lbs which is twice what the standard torque for the motor is. I am sure the margin of safety is likely four times the standard torque but the Uni 1100 did have a reputation for twisting the cranks!

AL

[LTD Project]

Thanks Al
Will do what you suggest this morning.

I checked and rechecked that the stator was seated properly.

Are you saying that I may have twisted the crank by putting that much torque through it?

Should I have had it checked and welded when the engine was apart?

[LTD Project]

Update:

Did as Al said, removed alt cover and starter pinion gear. The starter motor still does not turn on the button, even though only having to turn itself.
So either battery, solenoid or starter motor itself?
How do I work out which.
Battery across terminals is 12.58 ctek charge program.

Should I remove the starter motor and connect it directly to battery…. Shouldn’t it spin freely or will it damage it with a dirct connection?

Is the solenoid easily testable?

[Al]

Oppologies, i thought we were talking about a mechanical problem.
At 95 ft/lbs i dont think there is a chance of twisting the crank. At 116 ft /lbs there only would be, if there were an already existing weakness. I am sure you could go to 200 ft / lbs without issue all things being well.The point i was making was that strategy of chocking the back wheel is not great for tightening the rotor bolt and the proper tool will get it where it needs to be without any likely other issues being caused. If the crank twists it will be immediately apparent when you start it. Vibration will be un-bearable. I am sure it will be fine with what you have done. The rotor may need more torque on the bolt to stop it spinning though.
You can power the starter direct from a battery with no penalty, it wont damage it. Standard method in garages i have worked in, to remove the solenoid from the equation, is to short across its terminals with a screwdriver or the prongs of an open ended spanner. I strongly recommend that you dont do this because it makes dangerous amounts of sparks, damages the threads of the solenoid and there is a chance it could weld the spanner on there and you cant turn it off. I am reminded of a mechanic who was working under the bonnet of a mini on a ramp. He reached into the engine compartment to do something down low and his watch bracelet shorted the solonoid terminals. Engine was on and it was in gear and it took off with him in front of it (welded to it)
Dont know about the Uni 1100 solenoid but the J version was something like £80 from KHI. i bought one from Electrex World and its been doing the same job for about ten years and was around £20. Might have been this one
https://www.electrexworld.co.uk/acatalo ... ml#SID=726
AL

[moizeau]

To test the solenoid remove the solenoid to starter lead and make sure you have full battery voltage going to the solenoid input terminal. If good, hit the start button and see if you've got the same voltage leaving the solenoid. You said it was clicking so the earth should be OK but worth confirming all earths are nice and clean.

[LTD Project]

Thanks guys, looks like it is the solenoid as although it clicks loudly, there is 0 voltage on the B post…
New one ordered via Z-Power, a week away…. I sure hope it fixes the problem and I don’t have any of the problems being envisaged in the earlier part of the thread.

What irritates me is that it is so disconnected from the work that I was doing…. Work on selector drum and alternator / stator, and guess what, the starter solenoid packs it in, go figure!

[LTD Project]

OK, well both positive power leads and the earth lead have been replaced, as has the solendoid.... the problem persists. When pressing start button you can hear the solenoid click but the starter motor does not spin.
If I bridge the starter motor body to the battery negative terminal and then press the start button, the starter motor spins willingly.
I should add that spinning the starter motor this way is only when the motor is free from the engine.
when the starter motor is located properly and bolted down, even the earth bridge approach used above is not effective. Do I need a new / refurb starter motor?

I have checked and cleaned the main negative battery to engine cable termination point.

Two thoughts/questions... the starter motor doesn't have a negative cable ( I assume that the thing is designed to earth via its body ? ) and should / would the addition of an earth cable be needed / would it help?

This is not an issue that has plagued this bike since getting it, it has always spun over and started, even on rough ol fuel. What might I have upset to cause this problem?

Thanks guys....

[Al]

Starter motor off the bike; jumper cables and it runs fine. Starter motor on the bike and tighten the feed cable to the stud and no go. Does the stud rotate as you tighten the cable to it? If so it may be loosing internal contact through the 'band' with the stranded cables to the brush plate!!
AL

[zed1015]

It sounds like the crank is locked.
Especially as you have had the alternator off.
Check that the starter gear behind the rotor rotates freely clockwise.
If not the whole assembly may be jammed against the crankcases due to either the thrust washers being in the wrong orientation or missing.

[LTD Project]

Thanks Al, didnt notice loose (turning) positive connection on starter motor, but I will go back and check for this.

Thanks zed1015, I can turn the crank by hand on the rotor and by spanner on the bolthead at the timing side of the engine, so it does not feel that bad, also I should have added that starter motor fully installed, but pinion/ idler gear not, so motor not trying to turn crank at this stage in the proceedings.

Thanks to you both for trying to help me move this forward. I might have to check the internals of the motor for anything obvious. After that, maybe buy a new starter motor. Given that ideas are running down now, I may have to break the bike if I cant get it MOT'd.
Perish the thought.........

[Al]

Run a jumper cable direct from the +positive side of the battery to the stud on the starter motor when it is bolted in. If it does not spin; remove the cable and turn the splined end of the starter by hand 90 degrees in any direction. Try the jumper cable again. Next turn the starter shaft 45 degrees by hand in any direction and try again. This will remove the ignition switch, starter button, solenoid, wiring and fuses from the equation together with the possibility of burnt out segments on the commutator.
It ran when it was on the floor with youre foot on it so it must do again. If it doesnt; you have an earth problem.
AL

[LTD Project]

‘Twas the starter motor, stripped and cleaned ( it was filthy inside) and then refitted. Engine started straight away, she now goes for her MOT next week. Fingers crossed.