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Post by boreham on Jul 12, 2020 13:31:34 GMT
A quick update after running in and general tinkering. Initially tweaking with the pilot jets to get the idle and initial throttle jetting correct, dropped to a 36 idle with 2 turns out the plug is a dark brown, just edging on rich but seems good on the road, a ram air filter now runs fine and quietens down the sound a great deal. On the road the engine pulls fantastic, straight off idle will happily pull through to 10K or run along at 30mph in 4th, the power is quite brutal with this pipe (pipe design bullet 150), with the power band coming in at around 7500rpm which is high with a scooter but fun! Gearing is 27/69 with a DRT input shaft which is giving aprx 10mph per 1000 revs, so 4K is 40mph etc.., it sits at 55-60 on the road with low throttle so it a surprise to a lot of people when a little Vespa 50 cruises past them! The engine itself has needed no fettling, just dropped the oil at 50 miles with no filings, the clutch has bedded in nicely and the initial jerky operation was just the plates settling, used heavier grade 85 oil as recommended. Had to tighten the usual areas as the power does tend to work things loose (rear light, number plate and stand all now nyloc bolted) The front disc kit has been a real pain, worked back to the bleed nipple on the integral banjo bolt, it simply will not seal and weeps over time, now replaced with a HEL unit and sorted, the pads supplied need to bed in, the material is quite hard so need to get them hot and cool over a few cycles. Overall happy with the engine, very powerful but easy to handle and ride, it does need constant high revs to get the best but it is designed that way, however it has enough torque to potter around the village. The pipe is fantastic compared to the usual supplier, it’s very powerful but even with the large carbon can is bloody loud, especially when it’s on full power! Never thought I would be pulling involuntary wheelies on a Vespa.
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Post by madmax on Jul 16, 2020 20:55:35 GMT
Did you use the extended HEL bleed nipple or just the standard lenght?
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Post by boreham on Jul 17, 2020 13:47:06 GMT
Did you use the extended HEL bleed nipple or just the standard lenght? Just the standard, the Caliper thread is quite shallow
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Post by madmax on Jul 17, 2020 19:09:57 GMT
Did you use the extended HEL bleed nipple or just the standard lenght? Just the standard, the Caliper thread is quite shallow Nice one, cheers.
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Post by rhys on Sept 17, 2020 9:14:34 GMT
Did you ever get this dynoed? Interested as the engine spec is pretty much what I am about to build but with Big Bertha or Franz pipe.
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Post by tzsteve on Sept 17, 2020 16:04:56 GMT
a nice looking scoot
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Post by boreham on Sept 17, 2020 17:55:39 GMT
Did you ever get this dynoed? Interested as the engine spec is pretty much what I am about to build but with Big Bertha or Franz pipe. Hi Rhys, yes at RJS bikes at Mallory park, had to fettle with the mid range jetting a bit but put out 24.8bhp, the pipe is seriously pulling at high revs, the power doesn’t really kick in TIL after 8k then pulls well past 10-11k, was too peaky, absolutely brutal on the road but being the 60mm is so torquey you’re can poodle around in 4th at 30mph, but if you want the power it’s all at the top. could play with the port timing but simplest is to reduce the pipe, it’s frankly a bit scary. upgraded to SIP shocks which has helped, even with the anti dive it now feels much better on the road, had it too 78mph but that’s enough! That is running the 34VHSB carb.
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Post by boreham on Sept 20, 2020 10:45:19 GMT
A mate had a new Polini Evo 2 pipe on the bench, could not find anything about them online, but as it’s made for the Evo reed kit we gave it a try, I had to drop the engine anyway to change the pipe so I stripped the top end just to check everything after the dyno runs, all good and allowed me to piss about with the base gaskets and get a better squish at 0.94, it was pinking a bit. The Evo pipe has a much narrower header at 31mm vs the custom pipe at a whopping 36.5mm, also the Evo has a much longer header pipe at 130mm before it expands, the custom once a meagre 40mm, hence its all revs (the longer the header = more low end torque, a shorter and expanding header = less torque, more revs) this is a rough overview! The pipe has turned it into a torque monster, a very different ride, off the low revs it just surges and tries to pull your arms off, also Max revs is around 7500rpm, had to adjust the pilot as it 4 strokes at low throttle but that just insufficient draw on the pipe. Just goes to show how impactful the pipe is on a 2 stroke! Fitted the SIP shocks, scoot sits visibly higher and much stiffer, the damping on the front had to be adjusted to full ‘slow’ rebound as it bounced down the road.
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Post by rhys on Sept 23, 2020 9:08:22 GMT
Yes the pipe makes a lot of difference. I'm going to try a Franz on my Polini Evo once I've actually welded it together. I got 25.5BHP on the dyno with the Big Bertha but the motor struggles between 4500 and 5500 which is a pain when riding on the road and not thrashing it through the gears. I'm hoping that the shallower diffuser will smooth that out a bit but not take too much off the top end. Will start my 60GTR build once the kit comes back into stock, will set the port timings lower for the road than the Polini as I originally built that motor for sprinting. Will be happy to get the same 24-25BHp but expect the motor to have wider more usable power band and more torque for the road like yours. Do you have the Dyno graph for me to have a look at please ? What primaries and size tyre are you using ?
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Post by boreham on Sept 25, 2020 16:49:40 GMT
Will dig out the graph and send over, I'm using 27/69 primaries with a DRT runner and standard gearbox, using 3.5 x 10 tyres, gearing is about perfect, you could drop the primaries to lower the power band but it will just bring the front wheel up in every gear, the 60mm kit really helps with a 54 stroke crank.
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Post by boreham on May 15, 2021 11:31:52 GMT
So lockdown gave a lot of Time for projects, I stripped the scoot back to a bare frame and decided to go back to the colour it came in, whilst apart I changed the loom to a BGM one (superb) and fitted the bar end indicators, they work really well and simple to fit with the loom and switch as it all pre wired The indicators are the SIP ones.
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Post by 50spesh on May 25, 2021 17:04:57 GMT
Looks great if you want a black horncast I have one spare
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Post by Deleted on Jun 3, 2021 12:53:19 GMT
Just had a read through this, fascinating build with the usual ups and down of performance parts. Also the usual - in, out, open it up again of the engine 😂 I often wonder how gasket manufacturers keep up with scooter enthusiasts needs haha. What stage is it at now? All running and being used hard? Or in the shed too scared to use it incase something breaks? Cracking build by the way 👍 also - user name.. 🤔 are you from boreham?
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Post by boreham on Jun 3, 2021 16:47:10 GMT
Hi Matt, always ridden hard, unfortunately the motor is in bits again due to missing n third when the power kicked in, turns out to be a third gear cog, just about to update the thread with an update on the gearbox rebuild. Boreham was based on building and rallying group 4 historic Escorts, hence built at the holy grail of early performance Fords!
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Post by Deleted on Jun 3, 2021 17:09:58 GMT
Hi Matt, always ridden hard, unfortunately the motor is in bits again due to missing n third when the power kicked in, turns out to be a third gear cog, just about to update the thread with an update on the gearbox rebuild. Boreham was based on building and rallying group 4 historic Escorts, hence built at the holy grail of early performance Fords! Ridden hard is what its all about 👍 motor being in bits again is standard lol - anything Italian with a motor demands more attention than my ex wife 😂 and she is a proper twat. Ah - tenuous boreham link then 😉 I was born and raised there, use to be a bit of a utopia... now its just another soullessgarden village waiting to be linked up to the city... ive moved to the outskirts but developments and bypasses are nipping at my heals so I fear my final move and resting place will be a long long way from chelmo... Looking forward to the thread update for sure 👍
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Post by boreham on Jun 3, 2021 17:53:55 GMT
So....... after a spring of running the engine in, it was clear the power had found a weak link in 3rd gear, at higher revs/power (10K) it occasionally jumped which was both terrifying and dangerous to the motor. I had used a standard PK gearbox and i really needed a solution to cope, I looked at alternative shafts, selectors and gears and finally bit the bullet and ordered the Crimaz complete gearbox. The gearbox is the short version, there are 3 options, a touring gearbox with a short 4th, the middle short box with short 2nd to 4th, then an ultra close for racing. The gearbox comes fully built and pre shimmed, with the tree. The ratios are Drive shaft 55-53-50-49 Tree 10-14-17-20
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Post by boreham on Jun 3, 2021 17:57:59 GMT
The gearbox is a thing of beauty, usual Crimaz quality Whilst apart I also reworked the transfers, lowering and shaping to make better flow at BDC, also opened the rear feed on the boysen port, should release the absolute power left in the setup. Also reshaped the spacer and added alloy gaskets as the multiple paper items to get the squish always had me worried on sealing. Also upgraded the reeds, I found a motor cross store that cuts carbon reeds, the Quattrini uses a CR250 reed block so 0.4mm carbon ones were off the shelf. Straight fit, plus they supplied much better gaskets than the thin paper ones you get with the original kit, the reeds were £14 so a bargain.
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Post by boreham on Jun 3, 2021 18:25:10 GMT
The last thing was the clutch, as we should be in the late twenties with the power I didn’t want to damage the CM4 unit, plus not wanting to strip the bloody thing again I opted for the PLC Corse item. The CM4 is rated at around 25bhp and has been perfect in the 20-30 miles of use, it came out unmarked so will be moved on, a perfect engineered clutch but I wanted peace of mind. The PLC unit is rated at 30+ and built for the track, it really is a great, but pricey option and comes in a funky box! Lastly clearcoated the Pipe design exhaust to put back on. Back in the shed on Saturday for the rebuild, looking forward to getting this back in and running.
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Post by boreham on Jun 13, 2021 9:37:16 GMT
An update on the Crimaz gearbox, all back together and off for a test ride. The box is a straight plug and play and incredibly well engineered as expected, the selector pawls seemed a little tighter to get in but I think that’s just every part is closely manufactured so it needed the selector bolt to be loosened off a bit of wiggling, the real hub splines are very tight, you can’t push the hub on, measured with a Micrometer the tolerances are very close so needs aligning and winding on with the rear hub nut, maybe an aftermarket rear hub. The PLC clutch is built in situ, I had to chamfer the inner edge of the casing to get it in, I am using a Fabbri billet basket so would go in with a standard type basket, it is a bit of a fiddle to build as you have to compress with the tool provided, then add bolts to hold it in place to get the top plate on, PLC have put a video on YouTube to explain as although the clutch comes with all the parts there are no instructions. On the road, the gearbox is simply fantastic, a gentle run first as the engine has been rebuilt but selects effortlessly, and the close ratios make it run through the Rev range nicely and keeps the engine in the revs, after a short run and checking everything was fine it was time for a power run. The clutch is very light, it feels like a standard 3 plate, very odd after needing arms like Popeye with most performance unit, it was a bit jerky for the first couple of minutes until the plates and oil gets around but now light and smooth and predictable! No creep at all. Hitting the power was a fun ride, the engine sits in the revs, with the M1R not having the real power until 8K+ It makes full use of the power, the ratios are just right and with the build quality you know the abuse is fine, change downs are smooth and noise free, the selector spring is clearly uprated but not stiff Overall a high priced item but we build these engines with £600 cylinders and cranks/clutches and until now used standard boxes with various upgraded parts which sometimes can be a pain getting everything to just work, but this is a great solution for high powered engines or racers which is the intended market.
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Post by Deleted on Jun 13, 2021 21:37:12 GMT
Incredibly engineered...? should fucking think so for what you paid 😂 be sure amd let is know the gains per £ achieved.
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