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I will probably be attempting to start my NC 250 this weekend. Before I do, I have 2 basic questions:

1) does the oil level need to be checked with the dipstick screwed in all the way and the bike on the center stand with a cold engine?
2) can I run unleaded fuel? or do I need to add some lead substitute? what octane should I use?

Thanks

-Adrian

[quote= narrow_monza ...
" does the oil level need to be checked with the dipstick screwed in all the way and the bike on the center stand with a cold engine? "

____ The factory's dipstick checking-method isn't very trust-inspiring (as regular dipstick oil-level checking usually goes), since it can possibly seem inconsistent.
Anyhow, MY answers are: 'no' to "screwed in all the way" ; 'yes' to motor level-set "on the center stand" ; and, 'doesn't much matter' to "with a cold engine".
__ Anyhow, if you have at-least 2-quarts in the motor-sump, then it's certainly okay to run the engine. _ (And [whilst on the center-stand], even just one quart can get-by for the short time until the cyl.head heats-up too warm.)



" can I run unleaded fuel? "

____ Yes. _ (As I don't think we've had much choice since before the '90s.)


" do I need to add some lead substitute? "

____ Ya really don't need-to, but that's probably better for the valve-seats,, however a little-bit of ordinary fuel-lubricant*additive would likely help well enough.
(* Often referred-to as 'top lube'.)


" what octane should I use? "

____ Unless your engine's piston is just a mere 8:1-CR. version, ya ought always prefer the highest octane normally available.



____ BTW,, don't forget to turn-off the petcocks, afterwards, (or-else you'll most-likely get fuel down-into your oil) !
____ Also, are you already familiar with the preferred method for kick-starting such Duc.engines with the magneto-type ign.system (so as to avoid THE much-dreaded 'KICK-BACK') ?


Duke-Cheers,
DCT-Bob

I for one would love to hear the preferred starting procedure for the 250 narrow case with AC ignition, as I will be in the same position with my bike in less then a month if all goes to plan.

DewCatTea-Bob wrote:[quote= narrow_monza ...
" does the oil level need to be checked with the dipstick screwed in all the way and the bike on the center stand with a cold engine? "

____ The factory's dipstick checking-method isn't very trust-inspiring (as regular dipstick oil-level checking usually goes), since it can possibly seem inconsistent.
Anyhow, MY answers are: 'no' to "screwed in all the way" ; 'yes' to motor level-set "on the center stand" ; and, 'doesn't much matter' to "with a cold engine".
__ Anyhow, if you have at-least 2-quarts in the motor-sump, then it's certainly okay to run the engine. _ (And [whilst on the center-stand], even just one quart can get-by for the short time until the cyl.head heats-up too warm.)

I have 2 quarts in there now.

____ BTW,, don't forget to turn-off the petcocks, afterwards, (or-else you'll most-likely get fuel down-into your oil) !

Hmm, interesting. Why/how would gas get in the oil?

____ Also, are you already familiar with the preferred method for kick-starting such Duc.engines with the magneto-type ign.system (so as to avoid THE much-dreaded 'KICK-BACK') ?

I'm afraid I'm not, and I'd hate to experience the kickback. In the past I had push-started it, but now that I re-installed the kick-start and implemented the repair that Jim posted in the Tech section, I'm eager to use it. Please share the preferred method.

Thanks!

-Adrian

[quote= narrow_monza ...
" Why/how would gas get in the oil? "

____ Fairly simple... At-least the stock side-bowl carbs are pretty-much unable to completely stop fuel-flow from the gas-tank, and-so the fuel slowly leaks into the carb.throat and drips-down the inlet-duct & into the intake-port & past the in.valve, to next leak-past the piston-rings and then run-down into the motor-case oil-sump where it then gets mixed-up with the motor-oil.
__ I wouldn't trust ANY carb to completely prevent this quite COMMON oil-contamination issue !



" Please share the preferred method. "

____ A more detailed explanation for the preferred kick-starting method has already been previously posted in at-least two other older threads, so I'll be rather brief with this response.
__ Always very-SLOWLY work the kick-lever until the cyl.compression finally conspires to slow the lever's progress. _ Then (even more patiently), keep light pressure on the kick-lever as you feel the compression bleed-down,, and as it bleeds-away towards next-to-nothing, then STOP ! _ (It may take some practice to develop the sense to realize exactly just-when to give-up squeezing-out the compressed-air and release your foot-pressure off the kick-lever, so as to not go TOO-far.)
At this point, the crankshaft position should then be as near as possible to power-stroke TDC - (or well within 10-degrees of it).
Then next, you must let the kick-lever reposition back to as much swing-throw as it can normally achieve,, and then (with your leg positioned to your best advantage), WHOLEHEARTEDLY -(without ANY timidness !) kick-down the starter-lever with pretty-much ALL your might & speed !!
That-way, not-only will your-force attempt to push the crankshaft & piston past the (rather early) point-of-ignition,, but ALSO, (and most importantly), the flywheel will then much better store your inputted momentum-energy to greatly help overpower the (dreaded) early ignition-force, and continue-forth onward to normal engine-rotation (and hopeful start-up).
Otherwise (if ya don't care to take such patience),, the commonly done rather randomly-set kick-start technique will most-certainly often turn-up a quite unfavorable 'snake-eyes' chance-result, with the UNDESIRABLE kick-BACK (that's normally inherit with Ducati's mag.powered ign.system) !

____ Have you ever checked to see if your particular Motocross-motor has any AAU connected to the points-cam ?


Dukaddy-DUKEs,
DCT-Bob

" Why/how would gas get in the oil? "

____ Fairly simple... At-least the stock side-bowl carbs are pretty-much unable to completely stop fuel-flow from the gas-tank, and-so the fuel slowly leaks into the carb.throat and drips-down the inlet-duct & into the intake-port & past the in.valve, to next leak-past the piston-rings and then run-down into the motor-case oil-sump where it then gets mixed-up with the motor-oil.
__ I wouldn't trust ANY carb to completely prevent this quite COMMON oil-contamination issue !

I make it a habit to always close the petcocks but wasn't aware fuel can make it past the carb float bowl. Thanks for the warning.

" Please share the preferred method. "

____ A more detailed explanation for the preferred kick-starting method has already been previously posted in at-least two other older threads, so I'll be rather brief with this response.
__ Always very-SLOWLY work the kick-lever until the cyl.compression finally conspires to slow the lever's progress. _ Then (even more patiently), keep light pressure on the kick-lever as you feel the compression bleed-down,, and as it bleeds-away towards next-to-nothing, then STOP ! _ (It may take some practice to develop the sense to realize exactly just-when to give-up squeezing-out the compressed-air and release your foot-pressure off the kick-lever, so as to not go TOO-far.)
At this point, the crankshaft position should then be as near as possible to power-stroke TDC - (or well within 10-degrees of it).
Then next, you must let the kick-lever reposition back to as much swing-throw as it can normally achieve,, and then (with your leg positioned to your best advantage), WHOLEHEARTEDLY -(without ANY timidness !) kick-down the starter-lever with pretty-much ALL your might & speed !!
That-way, not-only will your-force attempt to push the crankshaft & piston past the (rather early) point-of-ignition,, but ALSO, (and most importantly), the flywheel will then much better store your inputted momentum-energy to greatly help overpower the (dreaded) early ignition-force, and continue-forth onward to normal engine-rotation (and hopeful start-up).
Otherwise (if ya don't care to take such patience),, the commonly done rather randomly-set kick-start technique will most-certainly often turn-up a quite unfavorable 'snake-eyes' chance-result, with the UNDESIRABLE kick-BACK (that's normally inherit with Ducati's mag.powered ign.system) !

Great info, will practice this approach and hope for the best

____ Have you ever checked to see if your particular Motocross-motor has any AAU connected to the points-cam ?

Yes I have an AAU of type AA367B. By the way, does it need to be oiled?

[quote= narrow_monza ...
" Yes I have an AAU
does it need to be oiled? "

____ I'd just give it a light-coating of grease from a spray-can.


Duke-Cheers,
-Bob

Starting: Put bike in gear, roll bike backwards until piston comes up on compression, put in neutral, kick.

Nick wrote:Starting: Put bike in gear, roll bike backwards until piston comes up on compression, put in neutral, kick.

____ This can possibly be a faster method that's also easier to learn & master, than that which I've suggested (which allows near 700-degrees of engine-rotation to build-up flywheel momentum),, however this-way provides about 20-degrees less rotation (which shouldn't matter much to anyone over a 150-pounds in size). _ In fact I-myself had come to use this particular kick-starting prep.method after I got a 10.5:1 MC-piston installed !
With a 8:1 piston, this prep.period is probably no faster to get accomplished,, however may still be easier to learn to do.


Dukaddy-DUKEs,
-Bob

Speaking of pistons, is it possible to identify the piston in my bike by reading what's stamped on the top part? I can see some digits/letters through the spark plug hole.