Forgotten Era Speed Hill Climb 350 Morini MKII

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72degrees
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by 72degrees »

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Finally ready again for Loton Park tomorrow.

The sporty seat gives it a pleasing flat track racer look and gives a very nice riding position. Now lubricated by Motul 15w-50 semi-synthetic. Next option will be a full synth 10w-60. I've persuaded myself it sounds a bit less mechanically noisy but I'm not totally convinced. No signs of nasty metal bits in the filter when I drained the running in Halfords 10w-40 semi-synthetic though.

I managed to silver the solder the silencer/pipes junction to give good gas tightness. I then found that Autosul 'bluing remover' pretty much does what it says on the tin (well bottle).

I've got the carbs reasonably balanced on the Morgan manometer by tweaking the adjusters on the Tomaselli QA throttle but it is behaving slightly oddly. Inclined to suddenly die if I try and get the idle speed well below 2000. I'm wondering if the upgraded ignition is not sparking well at low rpm, but then it kickstarts easily. Perhaps still a bit of an air leak somewhere but no sign of popping on the overrun (not on load though). The stator winding could do with being a bit higher resistance and the rotor stood in a Spanish barn for years so may really need re-magnetising. I'm taking the standard transducers along just in case I have to swap back. Picks up well on a snapped throttle once warmed up though. The proof of the pudding and the front tyre will be first practice tomorrow.
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72degrees
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by 72degrees »

I'm so glad I took the OEM transducers to Loton. In first practice it wouldn't rev past 6000 under load.
Not carburation, as that was unchanged. I had taken the precaution of mounting the NLM module and some 2 pin coils so that it was easy to put the known good transducers back on between runs, though I had a truly wasted spark system then, as I left the coils and spanky new HT leads/caps tucked away (but not activated as the green wire was only feeding the OEM transducers).

Going much better then, though I was braking way, way too early after the April experience. The hill had been totally resurfaced with 'shell grip' which was amazingly grippy dry (though less so when wet yesterday apparently). The race roadrunner front tyre gave me no qualms. Last run was a 77.99 so only about a second quicker than first practice on old, cold tarmac (and old front tyre) in April. I stayed on though and was only second slowest time of the day. Over 10 seconds slower than my Morini 350,personal best at Loton but that was set 36 years ago ;)

The problem felt like the ignition advance was going retarded at over 6000, if you see what I mean, so I am suspicious of the NLM module. It is the later two cable group version. The older one cable box on the 375 works very well. A substitution test is in order, then possibly a trip to NLM to be tested on their diagnostic rig. I'm pretty sure the NLM module is supposed to be compatible with any pickup (including their own) but now I'm wondering.

The time may have come to go for a Sachse system.

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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by EVguru »

I just looked up the Naraku coils. They're claiming twice the voltage output.

You only need about 12Kv to fire a spark plug with a typical gap. More if it's contaminated and/or if the ceramic insulator is starting to conduct slightly, but really nothing over 16Kv.

With capacitive ignition systems, no energy is stored in the coil, that's what the capacitor is for. That's why the coils are usually so much smaller than those in an inductive system. The spark voltage is the capacitor voltage times the turns ratio of the coil.

The Naraku coils my not be compatible with the capacitor voltage of the Morini system.
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http://www.morini-mania.co.uk
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72degrees
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by 72degrees »

Hmm. I shall certainly be checking the coils resistances against the ones on the 375 and then perhaps a substitution test . Easier to diagnose on that by taking it out for a ride rather than on the hill climb bike. You could tell a difference when blipping the throttle on the paddock stand once the transducers were put back on, but it was fairly subtle. If the 375 goes OK on the Naraku coils and its own module that would pretty much confirm where the issue lies. I never did get round to checking the advance on either machine with a strobe which might also be informative.
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72degrees
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by 72degrees »

72degrees wrote:Hmm. I shall certainly be checking the coils resistances against the ones on the 375 and then perhaps a substitution test . Easier to diagnose on that by taking it out for a ride rather than on the hill climb bike. You could tell a difference when blipping the throttle on the paddock stand once the transducers were put back on, but it was fairly subtle. If the 375 goes OK on the Naraku coils and its own module that would pretty much confirm where the issue lies. I never did get round to checking the advance on either machine with a strobe which might also be informative.
Well curiously the primary and secondary winding resistances of all four coils check out the same. 4 ohms and 3000 ohms (so much for the 'high voltage racing tag on the Nakaru ones - still orange has to be faster). A substitution test of the module is now a must.
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72degrees
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by 72degrees »

QED. No need to try riding the 375 with the two cable group NLM module hooked up to the NLM supplied coils. Seems to only run on one below 3000 and doesn't rev very well on two above that. Whereas the FE bike with the one cable group NLM module (intriguingly marked Kokusan), used with the Naraku coils,is as crisp as you like, even crisper than on the OEM transducers.

NLM did say something about how they were now using different coils to the ones they supplied with the first module way back in 2012 but I can't imagine they would be other than a similar 2 pin min-coil? I'll give them a ring tomorrow. Meanwhile I'm going to make a proper dual ignition system installation on the FE bike using the Kokusan module/Naraku coils alongside the OEM transducers. It will need a bracket making to mount the coils to squeeze everything in but then I can do comparison speed trap results at Curborough just by swapping a few spade connectors and the HT leads over.

Still contemplating the Sachse or SWF ignition system for the FE bike though.
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72degrees
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by 72degrees »

Ah, after a long chat with Rob at NLM it seems their own later ignition module may not be compatible with the 2 pin scooter coils that the "Kokusan" one cable group unit I have works with. Yet this "Kokusan" unit is clearly not one from a Coguaro or other later 350 with that make as OEM.

Anyway, the coils they use with their own module now are larger and with a two screw fixing, so that suggests they may be significantly different in other ways. Fitting them (along with the module) in the space available on a 2C still having a reg/rec may be a bit of a squeeze but I'm sure I could find a way.

Naturally I'll be jury rigging first to make sure it then runs correctly or I'll certainly have to send the module back for testing.

Probably easier to put the two cable group and larger coils version on the hill climber. We shall see.
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by huub »

on my morini ( with SWF ignition) i've been using xv 250 coils bought from aliexpress,
i think i paid 10 euro each , including postage :D
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72degrees
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by 72degrees »

huub wrote:on my morini ( with SWF ignition) i've been using xv 250 coils bought from aliexpress,
i think i paid 10 euro each , including postage :D
I shall be making enquiries !
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72degrees
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by 72degrees »

Well the second generation NLM module is definitely fubar. Wouldn't work on the front cylinder even with the coils they now recommend (just like the XV250 ones Huub mentioned). The older module works really well with them, or the scooter 2 pin coils (using the same red pickup, stator, rotor, HT leads and (5k) caps. Starts very easily and idles ultra-reliably. I've rigged it up properly as a quick swap dual system so I can do speed trap comparisons at Curborough tomorrow - place bets now!

I decided it needed 'ace' bars to go with the café racer seat. The wide ones gave too much leverage on such skinny tyres. 2C OEM adjustable ones would be better with standard footrests - any one got a pair going spare?

As it is pretty much finished in development now , other than a possible engine/top end swap for next season to produce a 350 with L5 cam, I decide to take photos of the non-identical twins.

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72degrees
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by 72degrees »

Well the standby ignition system wasn't needed as the FE was starting and running very well all weekend.

I've never gone very well at Curborough and the only award I might be eligible for would be "The Consistency Cup". Seven times over two days (didn't bother with T2 on Sunday as it was honking it down with rain).
64ft Speed Time 64ft Speed Time 64ft Speed Time
314 Peter Fisher Moto Morini 350 NT 2.74 71.60 46.33 2.78 73.60 46.47 2.90 74.20 46.60
314 Peter Fisher Moto Morini 350 2.67 70.50 46.61 2.65 71.00 46.35 2.63 71.20 46.34

So less than 3 tenths variation and the first run on Saturday was the better by a hundredth than the last on Sunday. I've been going there for nearly 40 years and it's not the first time that my initial run has been the best even in good weather conditions. I don't like 'twisty sprints' as much as a proper hill climb - a bit like airfield race circuits in being a bit featureless. Didn't get round to swapping ignition systems. It was possibly getting to 9000 a bit sooner in 4th than with the OEM system in April as I grabbed 5th briefly a couple of times so my speed at maximum power calcs for a 14/44 final ratio are spot on. No point going for a 13 I think as 1st is pretty low. My 64ft times show the problems I was having with the binary clutch.

The ace bars were not a great success with standard 2C footrests. Perhaps I'll try some 'straight' bars.
The lad got down to 43.21 on his last run on Saturday and declared it great fun (cf. 37.10 on the KTM 250EXC). He was offered a ride on a Honda 450 on Sunday which meant one less 350 to better but even his time wouldn't have got any championship points as that would have needed a sub 40 second time. I might have accrued a point or two in the <400 Forgotten Era table though.

Time to swap the good NLM module back to the 375 for the Coalport hill climb on 6th August (just a cavalcade).
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by 72degrees »

'Vincent' straight bars now waiting to go on. The rear cylinder header pipe definitely needs lifting an inch or so but I don't want to start hacking at it yet - a project for the winter.

I managed to get the NLM 'performance' ignition pickup running (see other post)! Whether I will try it at the next event remains to be seen, though it wouldn't take long to swap back to the known good red one if required. After a long chat with another 'senior' competitor I decided I need to ride this thing more after all the cash it has consumed and the time I've spent on it, so I've entered Manor Farm, Wiscombe and Shelsley Walsh. I'll probably not get a ride at Shelsley as it's limited entry though. I'll also take the KTM to Manor & Wiscombe. The lad won't be able to ride but getting twice as many runs makes the fuel costs for the weekend seem less ridiculous and the venues are only 20 miles apart on the same weekend.

Riding the 375 up the old Coalport hill climb on Sunday reminded me that the L5 cam in that does seem to give it significantly more urge, so cunning plan C may have to be put in action this winter.
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by 72degrees »

New ignition module fitted and the timing on the NLM pickup checked. Pretty close to perfect now on both cylinders and it will idle amazingly slowly. I'll save the very fine tuning for a hill climb paddock where the noise won't bother the neighbours and someone can operate the throttle while I grovel on my knees peering at the alternator rotor. Starting pretty well but needs a firm kick. Good throttle response but the proof of the pudding... I've left the OEM transducers in place but not the old HT leads. The OEM red pickup will also always be carried to events in the spares box.

The Vincent straights needed handlebar risers, but some intended for trials bikes with 7/8 bars worked a treat. The riding position feels very nice indeed now. Just got to adjust the gear pedal height for my swanky new boots which are chunkier than my old Prexports.

Now I can turn my attention to the KTM. A trial fitting of the 38mm Keihin air striker carb (cf. 36mm standard) was very promising - once I remembered to remove the bung from the silencer!

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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by Ming »

I do like the look of that - may have to crib it for my 250 (or even look for a 350 engine...).
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by 72degrees »

Ming wrote:I do like the look of that - may have to crib it for my 250 (or even look for a 350 engine...).
A very similar riding position to a 2C with OEM adjustable bars - "the bars and controls fall readily to hand", as they used to say in road tests in "The Motorcycle". I'm not sure how well it would work with the standard 2C instrument binnacle and switchgear though.
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