MK III Starter Sprag?

Torontonian · Oct 26, 2015

Well after reading that it looks like I will be draining out the 20W50 , and using a Heavy Duty 30W as of tomorrow. It's cold out now anyways. And I doubt if it would negatively affect the operation of the 2 primary chain tensioners ? :?:

JimNH · Oct 28, 2015

Torontonian said:
Well after reading that it looks like I will be draining out the 20W50 , and using a Heavy Duty 30W as of tomorrow. It's cold out now anyways. And I doubt if it would negatively affect the operation of the 2 primary chain tensioners ? :?:

I wouldn't bother. The information I posted was just generic from a sprag manufacturer. Since you're still riding into the cold what are you running in the engine? Although I haven't changed my oil I do top it up with 15W-40 Rotela T. I'm running that in the primary as last time I had it apart it's what I had on hand, the 20-50 box was just an empty box and I had many gallons of Rotela. It's a diesel oil I use in tractors and other equipment and is probably much better than anything available when my Norton was new.

Please no one write how I'm going to blow up my engine by mixing oils.

Torontonian · Oct 28, 2015

I'm trying to blow up my engine by using 5W50 Full Synthetic Formula One from Canadian Tire Bank Corporation. It's on sale here at $28 for a 5 litre gold jug. Picked up 2 jugs. My primary reason is for it's cold starting consistent thin viscosity . I'm now changing my startup procedure in the cold too because when I hit the little green button (after generous carb ticklings ) the Dave Comeau starter will not engage with the starter train , it just spins. So I am treating it as it was intended , an electrical assister requiring the kicker and starter at the same moment , and this seems to work. After a warmup ,then a drive , I can hit the green button for instant engagement every time. I'm wondering which component doesn't enjoy the colder temperatures , could only be the backfire device or the sprague itself as I see it. Hurricane Patricia tail end outside today... so no drivings. :!:

JimNH · Oct 29, 2015

Torontonian said:
I'm trying to blow up my engine by using 5W50 Full Synthetic Formula One from Canadian Tire Bank Corporation. It's on sale here at $28 for a 5 litre gold jug. Picked up 2 jugs. My primary reason is for it's cold starting consistent thin viscosity . I'm now changing my startup procedure in the cold too because when I hit the little green button (after generous carb ticklings ) the Dave Comeau starter will not engage with the starter train , it just spins. So I am treating it as it was intended , an electrical assister requiring the kicker and starter at the same moment , and this seems to work. After a warmup ,then a drive , I can hit the green button for instant engagement every time. I'm wondering which component doesn't enjoy the colder temperatures , could only be the backfire device or the sprague itself as I see it. Hurricane Patricia tail end outside today... so no drivings. :!:

If the backfire device is slipping too easy it tends to be noisy. I found mine was seized up tightly - no amount of torque on the largest 1/2" drive torque wrench would make it release. After disassembling it and polishing up the various parts I was able to set it as the WSM requires. I've heard it slip and it clatters as it releases. It just has spring loaded detents so it doesn't slip smoothly. A sprag would probably slip noiselessly.

Torontonian · Oct 30, 2015

Could all be the backfire device doing it's job. Also there is a "clack" sound from the primary every time the motor is shut off. :?: . I have a friend with a MK 111 with the proper tools and bench who has offered to take it apart , inspect and calibrate to 50 lbs. slip . A nice offer , one of the benefits of O.N.O. membership.

ranmar850 · Oct 31, 2015

I've had it happen both ways. Jamming on after kickstarting, jamming after electric start. But the worst one is having it spontaneously jam on while riding--the regenerative braking as your electric starts tries to be a generator nearly throws you over the bars. Not good. I have removed mine for that reason, may revisit later.

Torontonian · Oct 31, 2015

Yikes , I can hardly wait for that exciting moment ! Almost as exciting as layshaft bearing lockup. :shock:

vidar hjelm johansen · Nov 3, 2015

Ranmar850
Hi
Read that you had a terrifying experience where the starter was trying to be a dynamo.
I experienced the same thing. It was scary, everything locked up. It turned out that the only thing that was damaged was the starter. Spragelse and all the gears was ok. anti backfire gear was ok and correctly set up.
I've tried to get an answer to what happened and why, without success.
I would like to know the answer to this, because I want to give the starter system a second chance.
Then with Dyno Dave's starter, and I do not want to experience this again.
Can anyone give me an explanation ???!
Vidar

JimNH · Nov 3, 2015

vidar hjelm johansen said:
Ranmar850
Hi
Read that you had a terrifying experience where the starter was trying to be a dynamo.
I experienced the same thing. It was scary, everything locked up. It turned out that the only thing that was damaged was the starter. Spragelse and all the gears was ok. anti backfire gear was ok and correctly set up.
I've tried to get an answer to what happened and why, without success.
I would like to know the answer to this, because I want to give the starter system a second chance.
Then with Dyno Dave's starter, and I do not want to experience this again.
Can anyone give me an explanation ???!
Vidar

Here's a video of a sprag in action. The elements are always in contact. a lot depends upon the drive and driven being hardened and lubricated. Perhaps the quality control of those pieces wasn't up to standard and wear suddenly increased once through the surface hardening allowing the sprags to tilt the other way resulting in a lockup. It doesn't sound like fun.

https://www.youtube.com/watch?v=Fsp3fm4KHs0

http://spragcomponents.co.za/faq/faq.asp

MK III Starter Sprag?

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