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 »

Not too bad a day for working outside so I decided it was time for the engine to come out of the 250 2C. I've videoed it running first in case I decide to sell it to defray the unexpectedly high cost of the 350 engine rebuild. Then gave the grotty area around the swing arm a deep clean. I haven't got time for a full strip down of cycle parts. Swing arm seems OK as do the forks (though they will get an oil change) and wheel bearings. It has Ikon shocks on the back which should be at least as good as the OEM Sebac units I reckon. At this stage it's very much a case of a test bed to see if it shows promise first, so cosmetics are last on my list. All the non essential bits will be removed and stored in boxes to leave a minimalist machine. I'm not sure the tank or seat yet. The tank it came with is so rusty it's beyond anything but the full POR15 treatment and it has no cap anyway. Plus it's a bit large for a lightweight hillclimb special. Shouldn't have sold the converted Puch moped one. It may have to do its first event with tank and seat borrowed from the 2C/375, but I think I may be able to graft something like a Suzuki GS125 one on which are available as cheap Chinese copies. So long as it's for a bike of the correct period, a pattern one is OK under the FE rules. It may eventually get a replica TZ250 fibre glass seat unit (like the original 81 special and FE bike Mk1) as that also provides somewhere for side numbers. No rearsets or Ace bars this time. Too much expense. It will keep the seemingly original (for Spain at least) high wide bars and standard footrests. For the short hills there's not much to be gained by a racing crouch and a more MX style position will be familiar to the lad when he rides it. Though he will have to get used to the gear lever being on the wrong side!

The 250 started surprisingly easily even though it had been sitting in a shed for months. It seems to spark very well, so I've definitely decided to rob it of the rotor and stator to get the project up and running ASAP rather than use the "not known good" ones sitting on the shelf. A bit of a struggle, as was the gearbox sprocket nut, but the breaker bar came to my rescue. The motor heaved out OK but the 350 will be going in as just a bottom end to save my back.

I was overjoyed to find the 350 rear pushrods and rocker gear in a box in the shed as I hoped. Filing the notches of the clutch centre is next but the spring studs are good and sound. The basket isn't too bad at all. Then I really must make a start on cleaning up and reseating valves. A pity you can't still get the special WeeVee light alloy valve caps, or can you?
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72degrees
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by 72degrees »

Yet another call to NLM for odds and ends. It's not until I come to re-assemble various sub components that I find more 'issues'. When I took the clutch off I noted vaguely that it had a three shims. On coming to check the free play I found that two were nothing like the usual ones. Much larger ID and OD and bear witness to having been fitted *behind* the spider! Even with just the one slightly thicker one, in the usual location, the centre isn't free enough for my liking. So I've decided to treat it to a new 'spider' and shim pack to get it just right. Clutch take up is pretty important on the start line if aiming for the magic sub 2 second 64ft lights time target.

The sump plug is some kind of pattern (or worse) item and was rather reluctant to come out. The threads in the case seem OK but I'll treat it to a new proper pattern one from NLM to be on the safe side (needs drilling for lock-wiring first anyway).

I was totally unsuccessful at removing a steel inlet stub from the duff head to go on a usable one that originally had alloy elbow items, so one of those had to go on the shopping list.

Still, the cylinders are now at my local place to be bored and honed. I went with +0.6 Sport pistons in the end, as though nobody else would know I was cheating (in the 251- 350 class) if I went for '375s'', I would. Time to start re-assembling the heads and valves now. I'm not sure with the project running so far behind schedule that I can be bothered to do any 'gas flowing'. A quick check of valve timing with a degree wheel before the top end goes back on at least established that it seems about right for an 'L' cam using the marks on the case and drive pulley.

It might even be ready for an attempted first start by the end of next week.
3potjohn
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by 3potjohn »

I've been following this thread as have nearly completed my 350 rebuild,as have had no spare weekend time, it;s taken a while. Today I think I'll get to start it up. I somehow managed to loose 1 cylinder head nut, and have searched inside the heads to make sure it is not wedged in somewhere.This is very frustrating.I never loose bolts or washers. I have plenty of suitable replacements though.
Lets hope I don't hear the sound of expensive clashing metal once it turns over.i've given the gudgeon pin circlips a damn good talking to as they are of the "curly wire" type on these pistons.
Might get up to Harland to watch all being well.
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72degrees
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by 72degrees »

Unfortunately, it took far longer for the boring and honing to be done than anticipated and so I only picked the cylinders up yesterday afternoon. I have to get at least one bike out of the garage to make room to allow comfortable access all round the 2C while slotting the 350 bottom end in, so that's unlikely to happen today in the pouring rain and cold. The heads are reassembled after more swearing than I remember before whilst popping the valve collets in to place. I had to use my extra strong reading glasses. I belatedly remembered that one set of rockers from this engine was robbed of bits for the 375, so the 2C engine will have to donate a set for now at least.

Even if it starts up OK and gear selection is fine there's no way that it will be ready for Hartland, even borrowing carbs, tank and seat (plus possibly wheels with only old rather than ancient tyres) from the 2C/375. If things go more smoothly from now on it may be ready for Loton in the middle of April.

Fingers crossed for your start up today.
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by MickeyMoto »

Pray tell how you used your strong reading glasses to get the valve collets in.....
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by 72degrees »

MickeyMoto wrote:Pray tell how you used your strong reading glasses to get the valve collets in.....
Ha! Simply to see what I was doing clearly at close range. I also used tweezers, as my valve spring compressor is not as svelte as it should be and access is difficult with unaided arthritic fingers.
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by MickeyMoto »

The perils of ageing. I have to take my specs off to do close work, then can't find them, then tread on them....

I use an old Panther compressor my dad used to use. Still works.
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by 72degrees »

Well at last the engine is off the kitchen table. Just as well as SWMBO is home from her skiing trip on Saturday.

The bottom end lifted in much more easily than the whole lump lifted out. I remembered that you have to put just the bottom rear engine mounting in at first on 2C/350 if fitting cylinders with the engine in place. Still a tight squeeze, but with it drooping down at the front as far as possible you can just get the rear cylinder over the studs. You also lift it up at the front once the rear head is on to make dealing with the front cylinder and head easier. I couldn't find my old faithful ring compressor, which was a very nice slim alloy band type. From previous experience I knew that the oil control ring is much trickier than the other two so I got a cheap one off Ebay. Not so nice, being steel and a bit too deep really for a Morini. If all else failed I was going to use the large jubilee clip and yoghurt pot trick but it was just about possible. My trials and tribulations with Nordwests years ago made me think of fitting the piston partway in to the cylinder first and then pushing the gudgeon pin finally through once in place, but that works best when an engine is on the bench. Not quite so easy when it's a tight j-j-jiggle to get a cylinder in position at all, particularly as these Vertex pistons really didn't want to accept the pins easily unless significantly hot. Anyway, I managed it. The compressor worked fine - just a bit of a struggle to get it out from between the studs once the rings were safely within the cylinder, but fortunately it was flexible enough to do that.

The heads went on with no drama and I robbed the 2C engine of its rocker gear. Both sets are in better condition than the surviving one on the 350 anyway. I'd already put the cam belt on using the standard marks and no nasty noises resulted from a very tentative turn over. I'm puzzled by the timing though. The cam is a bit of an unknown quantity. It's certainly in the right ballpark and I'm pretty sure it will run OK. I need to rig up a more accurate degree wheel and pointer system to confirm exactly what the valve timing is, but it's certainly 'hotter' than a Strada.

Put the missing engine bolts in and called it a day. Tomorrow the clutch can go back on (though I've already sorted the shimming whilst it was on the kitchen table). New plugs have also gone in so once the clutch is operational I can feel how good the compression is before putting the stator, rotor and pickup from the 250 on. Persuading the 2C exhaust system in to place (with a 350 engine) will be the usual fraught experience but it only has to be OK at the exhaust ports at this stage and I'll worry about getting the silencers properly in position once I know it runs OK. That will need the PHBH28s borrowing from the 2C/375. The jetting probably won't be right but it will be near enough to start - if it's going to.
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by 72degrees »

It Lives!

I couldn't bring myself to rob the 2C/375 of its carbs in case I had made a bish of the rebuild and it all had to come apart again. So more in hope than expectation I stuck the 22mm carbs from the 250 on.

Before that I frightened myself a bit by trying to check the stator. This 250 has weird ignition wiring with some kind of capacitor? in the green feed form the stator. A largish can which has an earth lead. For whatever reason this means that when you check the stator resistance or output voltage at each transducer green lead you get nothing! Checked at the connection before this thing it was 220 ohms and a reasonable AC voltage at kick start speed.

Managed to get the pickup rotor 180 degrees out first time (brain fart over the rotor marks) but I realised before too many abortive kicks.

As you might expect on tiny carbs it need both chokes to fire, but it started after a couple of kicks. Throttle response was a bit sluggish unless one 'choke' kept on, but good enough to confirm that on the centre stand at least it seems to select all the gears OK. That is once I'd remembered that you can't get a 250 remote gear linkage on with the front pot exhaust pipe in place.

A bit noisy in the clutch/gearbox area - the first gear cog bush was worn and NLM have only used items. Fortunately it was much better once the clutch cover was back on. The clutch is a bit below par. The oils seals must have been leaking a bit, and despite a good clean of the plates, the compression of new sport pistons almost defeats the grip at times. Two of the plates are a bit iffy but at least it is probably worth getting new ones now.
3potjohn
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by 3potjohn »

Glad to see the progress. I used a big jubilee clip rather gently to help get the piston rings compressed. Seemed to work OK. And useful to make up some new petrol pipe as mine was brittle with age and cold.A bit like me really. I lapped the exhaust valves lightly but not really any evidence of pitting etc.
Mentioning glasses i have rolled a BMW over a pair of expensive ones,and also had a postman stand on another pair when he chose an ususual route along my drive.
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by 72degrees »

Well it's now equipped with the PHBH28s temporarily borrowed from the 2C/375. The throttle response is much, much better, but it isn't quite as free revving as that engine. Maybe the cam (the other one is definitely supposed to be an 'L5'), maybe still a bit tight, and definitely restricted significantly by the small diameter 250 exhaust pipes. I don't suppose anyone has an old 350 2:1 system going spare? It will do for now though, so everything else non-essential has been stripped from the 250. It even seems that the centre stand is going to come off eventually without resorting to a hacksaw blade. Perhaps the benefit of having spent the years standing unused in Spain rather than the UK. The steel rear mudguard will be replaced with a lightweight plastic one. The front is more of a problem to lighten without fabricating some kind of fork brace. I have a DIY thick alloy one in the shed from the Original, Rotarini and MK1 FE versions but they had 350 forks so I'm guessing the bolt centres may not be right for the 250 Paoilis. I must dig it out and check.

It's not going to be a very attractive machine to begin with. The high bars give it a slightly flat tracker look. Fortunately, they aren't so high that the throttle cables from the other bike don't work for this evaluation period. It ought to get a 520 sprockets and chain conversion. The weedy 250 ones are shot anyway and it really needs a significant reduction in overall ratio if it isn't going to be a total snail. That will probably need a custom rear one making up anyway, as the 250 sprocket carrier is the same, smaller diameter, as the early 350s, so presumably a Kanguro one won't fit. Oh well, I can pinch the standard '350' sprockets and chain off the 375 for now.

I just got defeated by a stuck fastener for the first time that will need drilling out. One of the grub screws that clamp the light switch base to the handlebars. I'd soaked them with plusgas first and the one 2.5mm key socket head screw moved fairly easily so I got over confident and impatient with the other and rounded off the hole. I used an impact screw driver to shift the drain plugs for the forks, but guessing they would be well stuck in I didn't even attempt it without percussive assistance. The front wheel spindle clamps, and the spindle itself, had been soaking in plusgas for days and they seem fine. Investing in sticky Dunlop classic racing tyres might have to wait until after the first event as they are a fearsome price. The wheels can be borrowed from the 375 if I can make do with well scrubbed in pretty unremarkable road legal rubber.

Time to start thinking about how to attach racing numbers with minimum effort and get a breather catch bottle rigged up. I must also remember to drill the sump plug for lock-wiring.
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by EVguru »

72degrees wrote:I just got defeated by a stuck fastener for the first time that will need drilling out. One of the grub screws that clamp the light switch base to the handlebars. I'd soaked them with plusgas first and the one 2.5mm key socket head screw moved fairly easily so I got over confident and impatient with the other and rounded off the hole.
Get yourself some left hand drill bits.
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72degrees
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by 72degrees »

EVguru wrote:
72degrees wrote:I just got defeated by a stuck fastener for the first time that will need drilling out. One of the grub screws that clamp the light switch base to the handlebars. I'd soaked them with plusgas first and the one 2.5mm key socket head screw moved fairly easily so I got over confident and impatient with the other and rounded off the hole.
Get yourself some left hand drill bits.
I just drilled it nearly through and hammered a Torx bit in to it. Came out easily then.

Top tip. Don't unscrew a top yoke clamp screw on 250 Paoili forks too far or you may then wonder what the weird square nut lying on the floor under the front of the bike is.

I found the fork brace in the shed (another success for the never throw anything away strategy). The mounting holes are indeed at different centres but as the 250 ones are closer together I can modify it. I'm having trouble finding a suitable skimpy café racer style guard to go on it (the old fibre-glass one from 1981 was beyond re-use) even on Ebay.
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by 72degrees »

The front wheel from FE MK1 has been dug out of the shed. The tyre is a very fancy Dunlop racing one and though old, has been away from sunlight and stored with no weight on it. Still seems pretty sticky compared to a newish road tyre at the same temperature so it will do for now. The bearings felt a tad rough though, so new ones have gone in. Swapped the disk over from the wheel in the project 250. Just a bit of surface rust on the inner side and marking where the pads had been sitting, but I've seen worse. I had also kept a blanking cover that fits in place of the speedo one. This 'race' wheel has no speedo drive gear on it anyway. Much neater.

The front brake system from the 250 needs all new seals and probably pistons so more borrowing from the 375 for now. One slight snag. The braided brake line is long enough but with the M/C mounted on the higher wide 250 bars (not like the lovely adjustable 'ace' bars on the 375) the banjo orientation is a bit dodgy. Just needs twisting round, with hopefully no need for a complete re-bleed. Works OK even as it is but also looks like the caliper will need very slight shimming to get the disk running perfectly centrally (as it does when on the 375).

Dropped the back wheel out to extricate the 428 six bolt sprocket as a pattern to get a 520 version made up, if there is time. The rear brake lever on the hub has a return spring fitted to it. Not sure if it is DIY, or a later addition, as the 1980 250 hasn't got one.

The front mudguard mount/fork brace will definitely need new mounting holes drilling as the Paoili forks have them higher up as well as closer together. Natty lightweight red plastic trials guards have been ordered for front and back (as fitted to 1980s Italian trials bikes apparently so OK for 'a 'period' special.

I had broken my rule about never throwing anything out last year by finally getting rid of several battered old exhaust pipes. Just what I need to make up sleeves to get a good seal between the 250 2:1 pipes and the bodged up silencers. I think they may have started life as 350 silencers. Ebay to the rescue hopefully.
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Re: Forgotten Era Speed Hill Climb 350 Morini MKII

Post by 72degrees »

Now it can be told :(

I cannabilised the 2C/375 to get the project ready for Loton Park in April. I even had to rob it of the clutch plates and borrow the rear shocks as the Konis on the project bike had been bodged to fit by wrapping tape round the bolts to take up the slack in the larger mounting sleeves! Not approached with great enthusiasm, to be fair, as just launching it up my drive suggested it wasn't going to be as eager as the 375 with L5. It was starting OK though and not sounding unduly mechanically noisy.

Anyway, launched it off the line for first practice and it was pretty tame, though to be fair I hadn't had a chance to get a custom rear sprocket made so it was on standard 14/38 gearing. Handled quite nicely round Loggerheads and Triangle. After Keepers the red mist set in a bit as it was so dog slow and I revved it rather too high up the start of Cedar Straight for a not run in engine. On changing up it lost all power, or tightened up. I'm still not sure which because my two stroke finger had reacted automatically and pulled the clutch. I wobbled on to the grass and it kicked over but wouldn't start again.

Back in the paddock it started but by then I had convinced myself that it had nipped up, or the slight gear selection problems I had experienced when bench testing had bound things up. I also thought it sounded a bit rattly. Not wanting to hold everyone else up again with another red flag or do more damage, I decided to call it a day. In fact the split time to triangle wasn't the slowest bike but it did feel so dog slow.When I got home I just threw it in the shed.

For financial reasons I decided that ploughing the cash needed in to it to finish it wasn't worth it (carbs, sorting front brake, tank, shocks, decent tyres) particularly as we were only going to do one more event this season (for the same reasons). So I reinstated all the borrowed bits back on to the road bike and got an MoT for that instead. The same reasons crystallised my decision to sell the 1200 Corsaro. It was an itch I had to scratch but I have been finding riding it too intimidating so it had been languishing unused in the garage. It has now gone to someone who will ride it as intended. I've also just sold one of my Gilera GFR125s (who logically needs two identical machines?).

The question now is whether to revisit the project or spend the proceeds of at least the GFR sale on improving the suspension on my ER6n and fitting a comfort seat. Plan A is to bodge back on the 22mm carbs from the 250 and see if it will start again and what it sounds like. I may then put the rebuilt 350 engine in to the road bike to run it in properly on and evaluate further. The OEM 250 pipes were probably strangling it a bit and I didn't have time to do any re-jetting of the PHBH28s, so perhaps it will not be quite so sluggish with a 350 2:1. That won't be until the good weather is on the way out though. Riding the 2C/375 again has reminded me just how much I love that bike :)
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