[UncleErnie]

I've always heard you should turn off an iron barrle by pulling the decompressor, in order to prevent wet-sumping. 
So- I've been doing it that way with my AVL.  BUT; I got to thinking the two decompressors work differently.  Does it matter on the AVL, or should I just turn the key to the left and get off?

[ScooterBob]

I've always heard you should turn off an iron barrle by pulling the decompressor, in order to prevent wet-sumping. 
So- I've been doing it that way with my AVL.  BUT; I got to thinking the two decompressors work differently.  Does it matter on the AVL, or should I just turn the key to the left and get off?

You have your metaphors mixed up. Turn the bike off with the decompressor to prevent KICKBACK ...... park the crankpin at TDC by feeling for the compression to prevent wet-sumping .....

[UncleErnie]

oh...

Well, I got to 9500 miles today and don't think I've had any problems with wet-sumping. 
What are the symptoms?

[R.D.]

Uncle Ernie,

If all the bike fluid levels are within acceptable limits + catch can is checked regularly then i don't think there's any problem with'' killing'' an AVL500 engine with the kill switch @ engine idle with the key in ''ON''

Atleast i havent faced any of those  dreaded backfire / sprag problems- on start up,   in all my 4200 miles of ownership

May be i got a pretty lucky piece dat hasn't given any ' stranded on the road' kinda symptoms
But i am also very meticulous about servicing and preventive maintenance of my vehicle..........May be,  myself   being a Service Advisor for 4 wheeled vehicles @ start of my career has helped 

R.D.

[ScooterBob]

oh...

Well, I got to 9500 miles today and don't think I've had any problems with wet-sumping. 
What are the symptoms?

You start it up and the fire truck comes to your house to investigate why your garage seems to be on fire with all the smoke bellowing out of it ..... It's QUITE dramatic - but harmless unless you foul a plug. I screw up every now and again and forget to "park" the engine at TDC ...... D'OH! 

[UncleErnie]

My second sprag went out a long time ago, so  I just decided to kick it all the time.  Sprag gears are not inexpensive, either. 

So- the bike keeps running better all the time, I restored an Indian tank and it looks tits on the bike.   I guess I wait to worry about something when a problem comes up. 

Oh- here's another question;
I've run Seafoam in the tank once or twice, and Marvel Mystery oil all the time (gas only)
Do I still need to open up the top and poke around looking for carbon?  If so-  will there be gaskets to replace?

[ScooterBob]

My second sprag went out a long time ago, so  I just decided to kick it all the time.  Sprag gears are not inexpensive, either. 

So- the bike keeps running better all the time, I restored an Indian tank and it looks tits on the bike.   I guess I wait to worry about something when a problem comes up. 

Oh- here's another question;
I've run Seafoam in the tank once or twice, and Marvel Mystery oil all the time (gas only)
Do I still need to open up the top and poke around looking for carbon?  If so-  will there be gaskets to replace?

You know - I think de-coking is a thing of the past ..... As long as it runs just fine - leave it the heck alone and RIDE it! I screwed up on the old Duh-Nyepper once and took the heads off for a look-see and dutifully removed the carbon in the chambers and off the tops of the pistons. I removed all the dang COMPRESSION from it , too! I'll NEVER do that again! I had to ride it around for a week with the air shutter closed to carbon it BACK up so it'd run like it used to ...... Go figger! If it ain't broke - I ain't a-fixin' it! 

[UncleErnie]

Oh- you're a silver-tongued devil who knows what I want to hear...

You better not get me in trouble.

[ScooterBob]

Well - You gotta look at it this way. Back in the "Good Old Daze" we had to de-coke to keep the valve seats alive. The engines would "grow" carbon because the rings didn't seal, the gasoline was real and the mixtures were RICH, man! Nowadays, we have better metallurgy for the valves and seats, better machining for the whole engine, no lead in the gasoline to make deposits and carbies that can actually meter fuel precisely - so the end result is no carbon accumulation. I say RIDE, don't scrape ..... ! Hahaha!

[pneumatician]

Its Great to hear Scooter Bob reminding us how good the old days were.
My Velo Clubmans required a new primary chain at every oil change, decokes were done after work on Friday night. This so you could ride to the race meetings with mates at the weekend knowing your bike would be in fine fettle. Essential to emulate the race competitors on the way home.  You needed to arrive home before dark because the electrics (Miller) were useless and you had to pray that yet another dynamo belt didn't break or slip.  I could go on and on but even I would lose interest.

Steve

[cyrusb]

Don't foget to praise the modern oil that's available now. Remember that green glop that was once motor oil? Modern oil, is like it's from another planet compared to that .

[1Blackwolf1]

  Actually I run Penn Green semi-synthetic motor oil.  Works great as far as I can see.  But it doesn't load up like the green base oils of the 70's either.  Rich in ZDPP, and not bad price per quart, right around $5 buckaroos.  Of course I also run some marvel in the tank and in the oil also.  Hasn't hurt anything I can see.  Been running the marvel for years, haven't had anything coke up in a long time.

[UncleErnie]

Back to the original question;
Being willing to live dangerously on occasion, I have just turned the key off a couple of times.   (pretty scary, too!)  I must report that I notice NO difference at the next start-ups.

[1Blackwolf1]

  I usually just turn off the key myself.  On either the iron or AVL.  I do use the decompressor on the AVL to help to start it easier using the electric starter.  Guess I haven't had any trouble with kickback yet. 

[cyrusb]

Where did you originally hear to stop the motor with the decompressor? When I shut mine off with the key it is allmost allways against the next compression stroke which is good enough to prevent wet sumping. I don't believe the decomp valve is designed to see fire.

[UncleErnie]

Either  Uncle Pete or / and Scooter Bub. 

[cyrusb]

Well, I must admit I forgot which forum I was on. The AVL decompressor  holds the actual exhaust valve off the seat.  This is in your favor if you want to stop it that way. The bullet originals have decomps that I don't think were made for that purpose.

[Tiny Tim]

From my own humble opinion and personal experience, the sprag failure that I've had have all occured when the engine has stalled; with the ignition on and the kill switch on.

The higher compression engine means that, combined with the settings in the old (black) TCI unit, low revs or insufficient revs mean that when the piston approaches TDC on the compression stroke, if it doesn't have the momentum to get "over the top" it may well fire and send the crank spinning backwards.

This is no problem for the engine per say but it certainly is for the poor old sprag!

CLANG! There goes another one!

The Green TCI unit and a slightly higher tick-over rate seems to have made things last a little longer this time.

I've never had a problem whilst killing the engine with the key or the kill switch or even running out of fuel. The decompressor would certainly prevent the spinback problem.

That being said, when the next one goes, I'm going to wheel the bugger over to Henry Price and get him to fit one of his electric start Yanmar clone 406 c.c. Diesel engines.

[Joe28]

Jeese! I must have been absent that day in "Motorcycle School" when they talked about that!
This is my 3rd R.E., (my '99 was converted into a trails bike, man was thatLOUD and HEAVY, but fun on certan sections! My friends could ALWAYS hear where I was and I was doing, like when I'd stall it!. My '01 iron barrel  vintage and this '09 MIltary with the Cozy) and I've yet to do that. .
I pull into where I' wanna go, turn off the gas, (old habit) and turn the key off and go.
 Maybe that's way sometimes I check my oil level and it LOW and then when I get to work before I leave, it's HIGH!
Hmmmm, an old dog can learn new tricks!
When I ripped my motor down for the mains, it had 4500 miles and the piston and valves looked like it had 1000 miles, pretty clean and shiney!
You 'ol salts- remember getting your engine HOT and squarting a fine mist of WATER into your carb to "shock" the carbon outta the cylinders?
You used to be able to buy this oil?? stuff, that you warmed you engine up poured it into your carb as you'd race the sheet outta your motor to keep it runnin, smoke BILLOWING out the muffler, the directions were pour 1/2 can while running, the  drown out your motor with the  rest, wait 1/2 hour and refire the motor, (if you could).
It was "Engine Re build" in can!!!
I can remember filling my mothers kitchen with smoke trying that on a BSA!!
Joe
It's amazing what they came up with back in the daze!   And we bought it!

[UncleErnie]

uh... I hear you can do that with Seafoam.  I hear it smokes and smells a little.