Help Honda MC22 back from the Dead

Hi All,

About 6 months ago I picked up a badly cared for MC22,

I Have rebuilt the bike apart from a major engine strip, has anyone had an issue where as the bike won’t start after the following:

Now has 4 good sparks
Good compression
Fuel good too

But won’t start

Question I have is; can you have 4 good sparks and still have a faulty pulse generator?

IE I believe its firing at the wrong time?

The online available service manuals do not discuss in detail the pulse coil in enough details for me to understand it’s interface with the CDI unit

Cheers
Richard

 

Hi there,

Thanks for the speedy reply, yes they are connected correctly, as per the workshop manual

It’s the N model

I’m still thinking its the timing of the spark? Which I believe is sychonized by the pulse generator/cam ?

 

Yes I had checked it and found to be 420 ohms, so looks good

I found a good article on the pulse generator so checking the physical set up , just drained the oil to get at it

I’ve answered one of my original questions, you do not get a spark if it’s faulty, proved this by disconnecting it

Thanks for your help

I will be taking the left side cover later today, and will know more then

 

Yep must have checked 20 times or so

Plus made up a new set of NGK plugs and leads all new, New Iridium plugs, 4 heathy sparks too

You hear it blow back through the exhaust but won’t fire up

 

Yep about 3 times now

Cleaned jets, new insulators New clips and sealed

New air filter, new needle valves in case Of leakage

Done a compression test but then not cold 180 170 170 182
So no differential of more than 15 psi what they s would equate to warmed up not sure but suffice to start?

Cheers

 

Yep running Aux tank suspended over the bike with inline filter so you can see the fuel

Yep set the mixture screws @1 3/4 turns out plus new o rings

 

Any tips on staying logged in yep have ticked the stay logged in box or do you have to be a premium member ? Cheers

 

Hi there,

No I tick the box every time and still have to log in (Iphone 6)

Back to the bike

Found bike carbs 1 2 3 on 1 1/2 and 4 completely wound in? Yep that’s how I found them

These are the settings taken from 2fiftycc;

CBR250(F) + CBR250R(H): 2Ѕ screws
CBR250R(J+K) : 1 5/8 screws
CBR250RR(L+N) : 1 3/4 screws
CBR250RR® : 2 1/8 screws

So I set as 1 3/4 as standard and am running standard jets

So not sure where you got the 2 1/4 turns out?

I have now removed the side cover and all is well, pulse generator is set correctly

So I’m now left with perhaps the cdi unit?

So about to do some reading to see what in the past owners fault issues for changing

Cheers for your help much appreciated

 

Yes all correct, also the loom for the left coil does not reach to the right coil, and checked by the WSM

Thanks for your input

 

Apart from getting a voltage peak adaptor to totally confirm the pulse generator .91v and the ignition coils 178v all looks well with the CDI unit, have no way of confirming the timing of the sparks discharged without another CDI unit to swap out that is

So going to spend some time rechecking the amount of fuel getting to the compression chambers

The weird thing is the way in which it pops back through the exhaust, it’s not a proper bang misfire it’s almost like like a mortar being launched then sound like it runs back up the exhaust? Odd

 

I would but I cannot get it to run - cheers