Good morning all,
Just a quick question regarding the difficulty starting my nsr mc21.
I had to replace the crank thanks to a buggered center
bearing seal, all OK, carbs spotless, new iridium plugs, second
hand uprated Japanese coils, straight plug heads etc.
Problem Is that the engine requires a huge amount of
kicking over before the engine starts.
Plenty of fuel present as I fitted an additional fuel filter
that is easily seen just below the fuel tank.
Compressions are fine, cleaned the red cut off switch contacts,
Very sharp, bright spark on both plugs present.
Once started the engine ticks over at 1200rpm no problem.
Hot or cold, no difference still a bitch to start, especially if left for a while then restarting.
My bike is stock, carbs, jets, standard air cleaner and housing too and both stock exhausts present.
Only thing the engine has non standard are the plugs, heads and both coils.
Anyy ideas as to what might be causing this annoying problem?

What is your approach to starting the bike? Do you use the choke? Do you leave throttle closed, open or somewhere in between? I find the choke and no throttle needed until you sense its firing then open throttle a bit.

Is your battery fully charged? You might be seeing a spark, but it might be weak.

Have you looked to see if plugs are wet or dry after kicking it over but not starting? If very wet you are flooding the engine. If dry you may have a clogged idle jet.

Well, first off, I feel your pain! My MC21, since day one, has been a right PITA to start! So much so, I'm on my second kickstart lever, having broken (and welded) the first one. It got to the point where I was going to do the HRC delete, just so I had an excuse to bump start it!

Two things I will say initially, neither of which applied to me, but are something we have seen on other bikes over the years...

1. As Eric says, is your battery in A1 condition, and fully charged?

2. We have seen aftermarket/secondary filters restricting, or even preventing fuel flow, even though they appeared to be OK and showing fuel in the glass chamber.

If you suss this one, please post your findings, as I've struggled with my MC21 for 30 years! Particularly frustrating when I've seen people kneel beside their NSR and crank it by hand to start it!
_________________
Andy.
NSR-WORLD.COM

Please keep all responses to Forum posts on the Forum so that others may benefit.

Please DO NOT PM me for technical advice. My time is precious, and you will probably receive a faster response on the Forum anyway.

Check us out on Facebook! Please "like" our page!

Right o then,
Battery is in excellent shape being justvover a year old, i swapped it with the rgv's
battery just to eliminate it but made no difference..
12.7 volt upon turning on ignition andd 13.7 idling.
I also retro fitted a complete instrument panel got from Jauce in
Japan that has a digital volt/water temp. gauge along with a
Gear shift sensor so I'd thought the readings couldn't be way off.
The extra fuel filter i added is always full of fuel, forgot to mention that
the intank filter/fuel tap stop cock is one year old as I bought it along with
the battery.
I also fitted a second hand lightened flywheel, checked the pick ups
are both within spec resistance wise and cleaned regardless whilst fitting the flywheel.
I also changed the kick start pedal 'cos the dam thing was bent anyway.
Regarding the sparks, I get the impression that they fire randomly, the first few kicks I get no spark
then, out of the blue they appear..
I haven't started today, later on I'll pop down and have a look if a spark
is acutally present, first kick.
I'll be back..
Cheers
Forgot the initial start process, Doesn't make any difference anyway I try,
choke on, choke off no throttle, a wee bit open, identical symptoms, no start.
Plugs are wet, not soaked though.

Are you sure you've not stolen my MC21?!

Seriously, it sounds identical... right down to the bent kick-starter lever! I bent mine back into shape once too often, and it snapped. I welded it up, and it eventually snapped again, and I replaced it!

Sorry I can't be of any help on this one. I'm in exactly the same boat.


_________________
Andy.
NSR-WORLD.COM

Please keep all responses to Forum posts on the Forum so that others may benefit.

Please DO NOT PM me for technical advice. My time is precious, and you will probably receive a faster response on the Forum anyway.

Check us out on Facebook! Please "like" our page!

Right,
Good morning all,
I managed to get down this morning and see
what's going on spark wise.
Same old film, 1 nice, fat spark whenever the dam thing
wants .
Both plugs the same thing.
Connecting up a 12v test lamp onto the Utani
spII coil connector I kick it over
10/15 times and get nothing
then, out of the blue I start to see a series of pulses on the 12v test lamp,
not very bright quite dim.
Connected up a digital volt meter too, sometimes it shows12v then 3, 5, very random.
So, what's in charge of sending the 12V charge down the coils?
PGM? I'm gonna change the pick ups, even though they are within spec
What I can't figure is the random pattern of getting sparks,.
Andy, if I can fathom out what's wrong well and good, if not I'll show the bloody thing
over seas to you mate!

Just checked both pick up coil resistance, 213 Ohm both and both cold.