starting

[buell1203]

well no replies to my wiring query but i seem to be getting there! sparks on both cylinders. fuel as evidenced by wet plugs but it wont run. tried most things and just valve timing to check now. any ideas if it isnt this??

[robinh44]

Hi,

It would be worth checking ignition timing as well. To start with you can check by looking at the pickup with should have an arrow moulded into it, this should line up near enough to a notch on the casing. Have you got any technical books on the morini ie the blue book?

Regards

Robin

[MickeyMoto]

Just looked at your wiring topic, see you mentioned the transducers.

Just a thought, but are the transducers reversed and firing the wrong cylinder?

Mike.

[buell1203]

Yes I have a manual and original 75 handbook. I think that even if the transducers were reversed it would still run. I have used the one with the coloured wiring tag as cylinder one. The timing lines up but even if it didn't it can't be far out and would try to fire but there is nothing.
The transducers are, one grey with a hump and one red.prob aftermarket. Marked green x2 red and White.

Valves are .10. Will check the valve timing tomorrow. I have never run it so don't know how it used to be..
Thanks anyway.

[morini500dave]

Hi.
Re starting,do you get any miss firing or firing at all,have you checked that the cam belt is in the correct position

Dave.

[buell1203]

yes i have a manual and a 75 handbook. been trying things today but but makes no difference. stator reads 210 bt my meter is not accurate. spark on both plugs. swopped over feed to transducers just in case but no change. leads give 5mm plus spark. removed staor and belt. checked and reset valve clearance abd timibg but no sign of life. all very frustrating. plugs get wet so fuel is there too.

[unreal]

Hi, this may be a long shot but check the pickup rotor isn't 180 degrees out, as it's possible to fit it either way (and yes i've done it...), you'd still get sparks but at the wrong time!

Simon

[buell1203]

yes. tried that too but ut was marked to keep it the right way around

[buell1203]

no decision reached but i am considering a kirby rowbotham or nlm aftermarket system. anyone have experience of these? i favour the battery/ coil system and would use points if i cud source a cam to drive them. i understand the diferences in the system but wonder which gives the most advantages.

[EVguru]

no decision reached but i am considering a kirby rowbotham or nlm aftermarket system. anyone have experience of these? i favour the battery/ coil system and would use points if i cud source a cam to drive them. i understand the diferences in the system but wonder which gives the most advantages.

There's little wrong with the stock system in good condition. My bike is all stock ignition, starts easily and pulls strongly well past 9000rpm.

The NLM ignition is the same circuit as the original, but with new closer tollerance components. The pickup part is the biggest improvemenyt giving a more progressive advance curve and more stable idle.

The stock type system will NEVER kick back if correctly timed and not relying on the battery has been an advantage on many occasions.

I wouldn't fit any wasted spark system that fires both cylinders together. Sometimes people will ask for advice after melting a rear piston. The first question is wether they have a Boyer (kirby) ignition fitted.

Coil and points? I'd much rather be riding than adjusting the gap(s). This isn't the dark ages!

How are you testing for a spark? You should remove the plugs and see if they fire whilst clamped (not just lain) against the engine. The ceramics may be faulty and be partially conducting. I've had this even on new plugs, mostly Champion, but also Bosche, and even NGK (my preferrred plug). What plugs are you using (make & type).

How fresh is your fuel? It can go off to the point that throwing a lit match in a puddle of it will put the match out! Even if it's not that bad it can make the bike very difficult to start.

Asuming the fuel is ok and so is the spark and that the engine has reasonable compression, it can only be that the spark is at completely the wrong time. Can you describe exactly how you have set the static timimg please.

Including a location in your profile might alow someone to offer local help.

[buell1203]

thanks for the info re the ignition systems. as for my timibg technique i have followed the manual to the letter. what i do nit kniw is whethet the system was correct to start with as it had wires and switches everywhere. the trigger is red. one teansdycer red and one grey. no spot! i have swopped the feed to each transducer and reversed the trigger rotor but to no avail. fuel is fress. pkufs are marelli as supplied with the bike. fairly new and spark well..although one is weaker but sufficient. carbs are rebuilt with new gaskets but both alloy choke levers broke off in my efforts to start it.

[Harry]

I think EVGuru is getting his electrics mixed up. Advance is controlled by the resistors in the transducers, the pick up simply generates a small voltage to trigger the thyristor in the pick up. You mention that you have odd transducers one with a bulge and different coloured stickers. One will be from a 500 and the other a 350. Also you may have a transducer from the early series without the diode. Miss matched could be causing you problems. It is quite alright to run 500 transducer on a 350 and vice versa as long as they are matched. If you have a strobe light then you can check if the plugs are firing and at the same time check the real timing. If you have a look the Dutch Morini web site they have a table of what pickups go with what transducers rather than me explain. If you do have sparks then you simply swap the pickup leads over at the transducer if not starting as opposed to just firing. I think without looking, that the red tagged lead goes to the back cylinder, but I am happy to be proved wrong. If you have wet plugs just have a check at the float levels or drop the float bowel incase a jet has not dropped out flooding the engine. It maybe a case of flooding the plugs then they will never spark in the cylinder owing to too high a rich mixture. ( Ship tankers only blow up when the tanks are being loaded or emptied, not when full). I have had on occasions the float needles sticking open and draining the tank into the cylinder and wondered why it would not start. You have to isolate whether it is the ignition or the carburisation. Not sure where you are, but if relatively local to Shropshire I am quite happy to have a look for you. I have been fiddling with these bike for a very long time including modifying and building for people. Most of the time people overlook the fundamentals and assume the problem is complicated.

[HoveActually]

As others have said the standard ignition (assuming all components are matched) works a treat.

If you haven't done so already you might want to read the tech report on incompatibilities of Morini ignition components here - http://www.motomoriniclub.nl/tech.html - explains it all really well.

Regarding the resistance of the ignition power supply coil in the stator, this should be closer to 300ohms rather than 200ohms according to Stuart at NLM. Mine measures 295 ohms which perhaps explains why my 3.5 starts so well.

[buell1203]

yes i have read up on component compatibility . mine do not conform hence my query as few things are set in stone. cannot be sure of the coil resistance as my meter is inaccurate. it should fire as it sparks the plugs but i accept it can make thibgs more difficult if not enough current gets through.

[HoveActually]

You've prompted another couple of thoughts.
1. If you look at the transducer wiring diagram on the Netherlands club site you will see there are electrical differences between the transducers. The function of the extra diode is perhaps critical and the 500 uses a higher value timing resistor, all together affecting spark generation / timing. You need to be absolutely sure that both transducers are matched to your pickup.
2. Assuming you are good on 1. then, if you haven't already done so, remove ALL earth connections, lightly clean with fine emery cloth till shiny, apply vaseline and re fix. Good earths work miracles, especially with ignition and tacho operation. A good spark outside the cylinder is not necessarily a good spark in a high compression environment.
Good luck for there is nothing more discouraging than a motor than should fire but won't.
Finally a bump start may be worth trying so long as you have fit / healthy pusher.