[Buckeroo]

I may have found what went clang during a kick start.  There are two broken teeth that look like they came from the gears that connect the crank shaft to the sprag clutch.  I have not located which gear yet, as that means removing the inner primary case to get at the back cover at the es motor.  I have read many threads on the sprag and it appears that it is very easy to break either the sprag or one of the transfer gears.

My questions are:
1)If I do nothing, will the more teeth bust off like dominoes falling due to the constant connection to the crank shaft?
2) will the use of the electric start break off more teeth?  I have not used the es in a while because of electrical issues.  That is on the list to repair.
3) Is there an AVL inner primary replacement available with out the es riser?  I don't want to do tapping and machining to adopt an older style Inner primary.  My machine skills are not that good.
4) If I have to keep the inner primary as is, and the gears have to be replaced, then will an air rachet remove the torqued inner nuts without special tools?
5) I read somewhere about a replacement Ignition module for lean burn engines.  I'm still unclear if this is a lean burn or not.  Can any body tell me?  And, if so, what do I order to replace the module to a green one?  If not a LB, will the green module help?

I am not looking forward to pulling out the clutch.  The thing that bothers me about all this possible replacement is that it can happen again very easily. 

[tooseevee]

I may have found what went clang during a kick start.  There are two broken teeth that look like they came from the gears that connect the crank shaft to the sprag clutch.  I have not located which gear yet, as that means removing the inner primary case to get at the back cover at the es motor.  I have read many threads on the sprag and it appears that it is very easy to break either the sprag or one of the transfer gears.

My questions are:
1)If I do nothing, will the more teeth bust off like dominoes falling due to the constant connection to the crank shaft?
2) will the use of the electric start break off more teeth?  I have not used the es in a while because of electrical issues.  That is on the list to repair.
3) Is there an AVL inner primary replacement available with out the es riser?  I don't want to do tapping and machining to adopt an older style Inner primary.  My machine skills are not that good.
4) If I have to keep the inner primary as is, and the gears have to be replaced, then will an air rachet remove the torqued inner nuts without special tools?
5) I read somewhere about a replacement Ignition module for lean burn engines.  I'm still unclear if this is a lean burn or not.  Can any body tell me?  And, if so, what do I order to replace the module to a green one?  If not a LB, will the green module help?

I am not looking forward to pulling out the clutch.  The thing that bothers me about all this possible replacement is that it can happen again very easily.

           Those are pieces of the sprag clutch.

            #1.  Yes. It'll just get worse if you don't have the whole thing repaired/replaced.

             #2  Yes. Same as #1 above.

             #3   I doubt it very much.

              #4  I don't believe an air ratchet is necessary if you properly lock the engine from turning over.

               #5  Yes. All AVLs are Lean Burns. AVL is the Austrian engineering Firm that developed the Lean Burn engine for RE. Their whole name is Anstalt fur Verbrennung skraftmaschinen List.

                Call CMW customer assistance to talk about the green module. They will ask for your VIN & will send you one for free.           

                 Here's a blown up sprag clutch:

http://www.google.com/imgres?imgurl=http://2.bp.blogspot.com/-cgYRI4BD_yo/Tc1m7LxHmEI/AAAAAAAAAC8/6zzfB70w4nM/s320/14%2Bwhat%252527s%2Bleft%2Bof%2Bsprag%2Bclutch.JPG&imgrefurl=http://handysnaks.blogspot.com/2011/05/slight-diversion-whilst-waiting-for.html&h=1200&w=1600&sz=141&tbnid=hGbqaC46VN4V6M:&tbnh=91&tbnw=121&zoom=1&usg=__0BLflksQCJZajxFJbO5RSgGcp_0=&docid=1A63V7qgAQ_Z9M&sa=X&ei=334jUunGLtXQsASMsYCgAw&ved=0CEwQ9QEwBQ&dur=578#imgdii=hGbqaC46VN4V6M%3A%3B0iS4bdV6HiqgGM%3BhGbqaC46VN4V6M%3A

            This is why I never use my electric start.

[Buckeroo]

Thanks tooseevee.  I kind of knew the answer already, but was hoping some experienced people here could shed some light on just how critical this could be.  I have not used the electric start in a long time.  But I like to have it just in case.  The two broken teeth are from one of those gears, but I will discover when I pull it all apart.  I'm suffering from the "can of worms" syndrome.  This bike is full of them.  I believe this broke when I was attempting to kick start the bike, and there was a loud clank.  I thought I had bent a valve, but they appear okay.  Those two teeth are the first evidence of something gone bad.

[tooseevee]

Thanks tooseevee.  I kind of knew the answer already, but was hoping some experienced people here could shed some light on just how critical this could be.  I have not used the electric start in a long time.  But I like to have it just in case.  The two broken teeth are from one of those gears, but I will discover when I pull it all apart.  I'm suffering from the "can of worms" syndrome.  This bike is full of them.  I believe this broke when I was attempting to kick start the bike, and there was a loud clank.  I thought I had bent a valve, but they appear okay.  Those two teeth are the first evidence of something gone bad.

           They're not teeth from a gear. They're the little "things" that are held captive in the sprag clutch basket. Picture below:

http://www.google.com/imgres?imgurl=http://i.ebayimg.com/t/Royal-Enfield-Sprag-Clutch-500cc-Classic-or-Electra-/10/!B4pwUDQCWk~%24%28KGrHqMOKjUEyKdE3iQkBMqp2kcm3w~~_35.JPG&imgrefurl=http://www.ebay.co.uk/itm/Royal-Enfield-Sprag-Clutch-500cc-Classic-Electra-/160995951012?pt%3DAU_Motorcycle_Parts_Accessories%26hash%3Ditem257c1b41a4&h=200&w=300&sz=7&tbnid=Dp1J0OzeA9upSM:&tbnh=90&tbnw=135&zoom=1&usg=__naYGQppMVCgnsyX9Wtx0cO1D3yM=&docid=X1qW2dydc3xnYM&sa=X&ei=5pAjUqvCFbKMigKY_oCYBA&ved=0CDYQ9QEwAw&dur=3843#imgdii=Dp1J0OzeA9upSM%3A%3BsdDW6ZKwMUzFxM%3BDp1J0OzeA9upSM%3A

         You have to face the fact that your sprag clutch is blown & will not get any better. (Sorry about this HUGE link).

[Arizoni]

Each one is called a sprag.

[tooseevee]

Each one is called a sprag.

           I KNEW I shoulda looked that up. Thanks.

            Here I am trying to advise a guy on his sprag clutch & I didn't look up sprag. I thought it was the noise they make when they self-destruct 

[D the D]

Makes me wonder why most motorcycles don't use a Bendix.  I don't think weight is a good argument when you look at all the gears in the sprag clutch setup.  Even Briggs, Honda, and Tecumseh use spiral gear engagement on mowers.
I just ordered a sprag clutch to replace my nonworking one before it comes apart.  I'll only use electric start if I kill it at a light.

[tooseevee]

Makes me wonder why most motorcycles don't use a Bendix.  I don't think weight is a good argument when you look at all the gears in the sprag clutch setup.  Even Briggs, Honda, and Tecumseh use spiral gear engagement on mowers.
I just ordered a sprag to replace mine nonworking one before it comes apart.  I'll only use electric start if I kill it at a light.

            Could it be the amperage a Bendix solenoid requires?

             And, yes, that's what I save my ES for, too.

[D the D]

            Could it be the amperage a Bendix solenoid requires?

             And, yes, that's what I save my ES for, too.

Amperage shouldn't be a problem with modern batteries.  I just added a picture of a Yamaha starter with Bendix clutch.  Bigger engines with higher compression manage without more gears in the starter gear train and the same output batteries.

[Buckeroo]

Opening a can of worms here.  I wonder what it would take to modify this pos with a bendix type engagement.  Not a machinist here, but I can do some things.  Seeing the Yamaha item above makes the juices flow.

[D the D]

Opening a can of worms here.  I wonder what it would take to modify this pos with a bendix type engagement.  Not a machinist here, but I can do some things.  Seeing the Yamaha item above makes the juices flow.

Yep!  I've been picturing things in my head.

[Ice]

Makes me wonder why most motorcycles don't use a Bendix.  I don't think weight is a good argument when you look at all the gears in the sprag clutch setup.  Even Briggs, Honda, and Tecumseh use spiral gear engagement on mowers.
I just ordered a sprag clutch to replace my nonworking one before it comes apart.  I'll only use electric start if I kill it at a light.

 You thinking what I'm thinking ?

[D the D]

You thinking what I'm thinking ?

Probably.  I wish I was a machinist with a shop to work in.

[Ice]

 Form Sprag in the US and Stieber of Germany are the worlds leaders in sprag technology and manufacture. Maybe they might have a type a sprag that decouples on kick back.

[Ice]

Probably.  I wish I was a machinist with a shop to work in.

 I know a few.

[potboiler]

Hi,
I have just bought a 2008 AVL Bullet 'Machismo'( 1800 miles on clock). and I am now horrified to read all these accounts of exploding sprags! I have this nagging feeling in the back of my mind that I now own a time bomb and that it is only a matter of time before it goes off.
Why was this defect not recalled by Enfield and rectified? Can you imagine that if this was a Toyota car with such a problem whether owners would tolerate such a situation? ( and then pay for replacement parts AND do the work themselves!). There are various consumer rights laws here in Britain whereby products have to be 'fit for use' and to last a reasonable amount of time. We motorcyclists are basically just doing product testing for free for Enfield!!   

[Ice]

Hello potboiler and welcome aboard !
 On this forum we tend to hold each and every little niggle up to the microscope, as so to speak, to share with all and because the lot of us here are just plain open and curious in general. Consequently you will hear of the ones that failed and not the hundred thousand that didn't.

 For sprag health, make sure yours has the green TCI box and use the de-comp instead of the key or kill switch for shutting down.

BTW Congrats! on your AVL Machismo.
I am doubly envious as none were imported "over here".
 
 

[Adrian]

Guys,

regarding Buckeroo's question #3 above, there isn't a direct kickstart-only replacement inner case, but the IS one that comes quite close and can be adapted.

The inner case in question is used on the later Indian home market 350cc 4-speed kickstart Electra, I'm using one on my AVL project which is based on a set of iron engine 350 cases. You'll need to drill and tap three 5/16" or 8mm holes in the drive side crankcase in the original mounting position (there are alloy bosses in the casting to take these), and if you haven't converted the gears on your Electra-X/AVL Classic/500 Machismo to right-foot shift you will also need to drill an accurate hole for the gear shift shaft in the inner casing.

Where do I get one of these?  Try here:

http://www.ebay.co.uk/itm/251021647790?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

Hopefully, a picture of it fitted (but no gear-shift hole) can be found here:

http://tinytim.forumcircle.com/viewtopic.php?t=2415&highlight=



Regards,

Adrian

[D the D]

Hello potboiler and welcome aboard !
 On this forum we tend to hold each and every little niggle up to the microscope, as so to speak, to share with all and because the lot of us here are just plain open and curious in general. Consequently you will hear of the ones that failed and not the hundred thousand that didn't.

 For sprag health, make sure yours has the green TCI box and use the de-comp instead of the key or kill switch for shutting down.

BTW Congrats! on your AVL Machismo.
I am doubly envious as none were imported "over here".

+1  RE was making over 50k bikes per year when yours was built, over 35k per year when my '07 was, and currently somewhere between 100k and 175k per year.  Six or eight of us post about a  bad sprag clutch, usually due to our own foibles of inadvertently allowing kickbacks somewhere along the line.  Those really aren't bad stats.  The Spaceshuttle solid booster was more likely to blow up than your sprag clutch is likely to crap out.
Dennis

[Buckeroo]

Probably because Bendix has a patent and RE would have to pay to use it.

Makes me wonder why most motorcycles don't use a Bendix.

[D the D]

Probably because Bendix has a patent and RE would have to pay to use it.

Nah, Mr. Bendix's patent had run out by 1925.

[Arizoni]

AIR, the Bendix was big and cumbersome.   It used a ratchet/pawl clutch that wasn't without problems of its own when it came to life.
That's why many Bendix units used a massive solenoid to engage it with the flywheel when the starter was used.
 When the starter wasn't being used the drive gear connected to the ratchet wasn't engaged with anything to keep it from breaking.

IMO, there's nothing wrong with a sprag clutch if it is designed to take the load/shock in the system.
Unfortunately, RE didn't size the Iron barrel or the AVL solenoid to take long term exposure to the loads and shocks the big engines can produce.

The UCE's seem to be much better but even they have had a few problems with their  sprag clutches.

[Buckeroo]

My Cub Cadet Lawn mower has a better starting system than these sprag gears.  I'm going to upgrade the ignition module and try to be very careful when kick starting.   

[Buckeroo]

Adrian, I love that red frame.  What are you doing with the tins?

[D the D]

My Cub Cadet Lawn mower has a better starting system than these sprag gears.  I'm going to upgrade the ignition module and try to be very careful when kick starting.

Your Cub Cadet has a Bendix type starter as does most outboard motors, even the big, several hundred horsepower ones, and probably your car.
I don't understand why anyone would say they are "big and cumbersome" nor faulty.  They're a spiral drive gear on a spring.  Elegant in it's simplicity.  It's the most common starter in the world.