Dave B
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Post by Dave B on Dec 21, 2016 10:15:50 GMT 1
The problem is that the high pressure pulse from the opening of the exhaust port of one cylinder arrives back at the other cylinder at a time when the pressure in its exhaust port needs to be low. The only way that a paralell twin can work well with a 2-1 is by fitting a 360 degree crank, with both cylinders at TDC together. Three into one pipes on a triple can work if the front pipes are the correct length, since the cylinders fire at 120 degrees, and the return wave can arrive at the next cylinder at an advantageous time. They can work, and there will be an engine speed at which they work very well- BUT, there will be other revs where they are utterly awful. That's why they can be good in a Snowmobile fitted with CVT transmission- it's basically a constant speed engine. If you just want the look, fine. If power and rideability interest you, use two pipes.
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Dave B
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Post by Dave B on Dec 12, 2016 10:31:13 GMT 1
I had scam email last week, sent to me on an email address that is not my real name- it's the one I use on here, actually! It looked exactly like a NIP- a notice of intention to prosecute, for being caught speeding somewhere up in Lancashire. It claimed to be from Greater Manchester Police- but the sender had an email address that showed that it had come from Russia. It did strike me as funny that Darowyn is a fictional character who lived in the late bronze age, so he was probably not driving a car in Bolton in 2016. A couple of weeks earlier he apparently parked his car illegally in Kent. He really gets about in his bronze time machine, obviously. I also had a phone call scammer, from one of those Indian call centres. offering to prevent people from cold calling me on the phone! I have a favourite trick for the ones who claim to be from HMRC, or BT or my bank. I ask for them to give me the authentication code that the bank, or whatever have agreed to use to verify their authenticity. They ring off so quickly, you hardly have time to get one last insult in. Cheers
Dave
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Dave B
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Post by Dave B on Nov 22, 2016 10:30:30 GMT 1
As the person who wrote the "Two Stroke Repair and Maintenance" book mentioned above, I'd like to thank you all for your kind comments. As an older guy who went to a school where I had spelling and grammar hammered into me in three languages for eight years, and then became a teacher, I'd like to offer my support to anyone who would like me to have a look over anything that they really need to be correct in spelling or grammar. I promise not to send it back covered in red ink and with "See Me" written at the end. I've had so much help from my fellow RDLC fans on here, I would not be expecting any money for this.
Cheers
Dave
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Dave B
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Post by Dave B on Nov 8, 2016 11:16:33 GMT 1
I know that it's not kind to pick on typing mistakes, but Begbie, I got to say that I'm very glad that I've never had a bike that needed a line of Coke before it would start. Who needs a yuppie yamaha?
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Dave B
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Post by Dave B on Oct 31, 2016 10:17:40 GMT 1
You can post negative feedback for the seller , of course.
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Dave B
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Post by Dave B on Sept 17, 2016 9:48:42 GMT 1
Oh so we're counting scooters as bikes are we Dave My attitude is that if it's got two wheels and an engine, it's a motorcycle- and I want a go on it. The other thing is that my list doesn't discriminate between things that I owned and rode regularly, and the ones that I called "cash crop" bikes, that I bought, sorted out and sold to raise money for the race bikes.
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Dave B
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Post by Dave B on Sept 17, 2016 9:38:03 GMT 1
Triumph Tiger Cub, Capri 80, BSA Gold Flash, Lambretta Cento, Lambretta GP200, Sunbeam S8, Sunbeam S7, another Sunbeam S8, NSU Supermax, AJS Model 16 350, Capri 125, Suzuki B100P, Norton Dominator 99, Bridgestone GT350, Ariel Golden Arrow, Gitane Champion Veloce 50, Suzuki GT500, CZ 175, Lambretta GP200, Yamaha FS1E, Honda CB400/4, Honda CB175S, Suzuki GS850, Yamaha RD250, MZ TS250, Yamaha RD80LC, Yamaha RD50LC, Yamaha TY175, Yamaha SR500, Scitsu/ Minarelli 50, Puch 250 Split Single, Aprilia RS50, Kawasaki GP500, Honda Deauville, Aprilia RS125, Yamaha YPVS350 hybrid, Suzuki RG50 Gamma. I may have forgotten a few more, but they are in approximate chronological order. The last four are still in the garage. Cheers Dave PS I forgot "The Radical" a kneeler FS1E racer, based on the remains of a Yamaha AS1 frame we found in a scrapyard. PPS. How could I forget three of the best: Rudge Ulster 500cc 1936, Francis Barnett Seagull deluxe 1938, Huvo/DRS 80cc GP racer.
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Dave B
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Post by Dave B on Jul 18, 2016 8:37:11 GMT 1
I agree, you need at least 14 CFM- which is what I have. The powdercoaters near here have a huge Rotovane compressor with a tank the size of a 40 gallon drum. The compressor still runs all the time they are blasting.
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Dave B
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Post by Dave B on Jul 16, 2016 9:08:38 GMT 1
Tuning techniques have changed radically since the 80's. Exhaust port shapes and timings are very different, and include "nozzles", "ski jumps" and extended tracts to cope with the transition from port window to round. Timings are different, from the big ports and the long durations of the 80's to concentrating on blowdown time/area. You need to talk to someone who knows their way around Engmod 2T. Cheers Dave
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Dave B
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Post by Dave B on Jul 12, 2016 9:30:23 GMT 1
I see that it has been taken down, "because there was an error in the listing". That would support the hacker theory, either that or he put up the listing at gunpoint!
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Dave B
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Post by Dave B on May 17, 2016 9:41:10 GMT 1
What you describe is often a symptom of "squared off " tyres.- but you have changed yours for the Avons, which are nicely rounded when new. So we are looking for something that moves as the sideways loading comes onto the bike. The obvious suspect is something loose at the rear wheel. I won't insult you by assuming that you have not tightened the rear wheel spindle, but definitely check the wheel alignment, and the wheel bearings. Cheers Dave
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Dave B
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Post by Dave B on Apr 24, 2016 8:47:07 GMT 1
Metmachex have another LC on the way. This one is a straight four, across the frame. Outer cylinders are reversed, inner ones the normal way round. It seemed to be attracting more interest than the latest Honda RCV race replica on the other side of the walkway!
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Dave B
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Post by Dave B on Apr 19, 2016 9:16:03 GMT 1
I've just had a look at my photos from Stafford Shows. Bearing in mind that I was only taking pictures of two stroke bikes, I can't say that I can see any significant difference in the number of japanese bikes between the Spring and Autumn shows. I'm going anyway, on Saturday, to show people my book, especially the people whose bikes are pictured in it.
Cheers Dave
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Dave B
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Post by Dave B on Apr 14, 2016 9:16:03 GMT 1
The obvious explanation is that the engine had a piston siezure and the previous (cheapskate) owner only had one cylinder rebored to +.002. The bike has not run much since then so the one newer piston is clean and the other hasmore carbon build up. Cheers Dave
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Dave B
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Post by Dave B on Apr 13, 2016 10:49:29 GMT 1
Will do. Cheers Dave
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Dave B
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Post by Dave B on Apr 13, 2016 9:03:18 GMT 1
A family friend, Martin, contacted me to ask if I could put together a Laverda Jota 180 degree model for him. The bike had been standing for over twenty years in a barn, mostly dismantled. Small creatures had eaten the seat. He had been thinking about a rebuild for a while, because it came with a box of new bits including some new chrome bits and a new seat. The sad part is that the owner had got one of those horrible degenerative problems. That meant that he was not going to be able to work quite soon and could no longer do the assembly himself. I could not really say no, in the circumstances. He brought the bike over in a farm trailer, and while unloading it, it was obvious what a big, unco-operative lump it was! Anyway many months later and after a lot of muttering, cursing and sweat, I got it all together and through an MOT. That was the brief, rather than a proper restoration, get the bike on the road for what might be a last summer of biking for him. I've got to say that the day I took it up for the MOT was not the best. It snowed, and I'm riding a very heavy, very powerful bike with the gear change and brake pedal on the wrong side, also, as a man of 5'8", the seat is so high that I can barely get on and off it. I did not enjoy the ride at all. Anyway, I had a spot of free time yesterday, so before Martin collected the bike, I thought I'd give it a run across the moor to check that everything was OK. This time I was starting to "Get it". It reminded me of the time I found myself riding one of the very first Kawasaki Z1. The Laverda is a big, old-fashioned 1970s superbike. It's fast and unlike the other 70's bikes, the handling is superb. It's rock solid on the bends, not as responsive as a modern bike, but so sure of itself that it's hard to believe its age. The picture tells the story of how happy Martin is the see his bike ready to go.
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Dave B
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Post by Dave B on Apr 12, 2016 14:52:39 GMT 1
The YPVS was running fine until the time it started up and the pipes sprayed the inside of the garage door with gearbox oil. You'll be getting an order for engine spares in a week or two, when I strip it down. The 80 frame is on the bench now, and assembly is started with the steering head and swing arm. This is what has caused the delay. Cheers Dave
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Dave B
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Post by Dave B on Apr 9, 2016 9:02:56 GMT 1
id be happy to put a link up for yopu book in the shop mate when and if i get mt web building tool fixed . Thanks Norbo. Cheers Dave
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Dave B
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Post by Dave B on Apr 8, 2016 8:47:40 GMT 1
You only have to ask. I shall be at the Stafford show, or I could send you a sticky label.
Cheers
Dave
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Dave B
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Post by Dave B on Apr 6, 2016 9:13:53 GMT 1
Thanks Steven! I think you might be the first!
Cheers Dave
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Dave B
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Post by Dave B on Apr 5, 2016 9:37:51 GMT 1
My new book on two-stroke engines was published yesterday. Here are the details if anyone would like to buy one. Norbo, you don't have to buy one, you will be getting a complimentary copy to thank you for your help with the RDLC/YPVS chapter! Cheers Dave
Book
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Dave B
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Post by Dave B on Apr 2, 2016 9:46:22 GMT 1
It did not take that long when I taxed the 1938 Francis Barnett. Finding proof of the original registration number in order to keep it was the big issue. That involved getting a photocopy of the original registration card from the place it was first registered. Fortunately the original owner was a family member, and I knew where he had lived, so the original registration office was easy to guess. Once everything was in place, it took about fourteen days.
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Dave B
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Post by Dave B on Feb 15, 2016 10:45:01 GMT 1
Noticed this on Facebook this morning. Worth a look I think, treasure amongst the trash- but be quick, the online auction ends on Wednesday. The more interesting stuff is after all the Chinese 125s! Granby Motors AuctionPublic Viewing: Saturday 13th February, 10am - 2pm & Monday 15th February, 9am - 4pm. Bidding Ends: Wednesday 17th February, from 11am.
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Dave B
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Post by Dave B on Jan 31, 2016 10:16:49 GMT 1
Something wierd based on breathing sounds on 6 Music. It's called "2" by "Forest Sword". (Probably not his real name) I shall not be zapping over to iTunes to buy the album though. There will be something good on soon.
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Dave B
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Post by Dave B on Jan 27, 2016 10:46:12 GMT 1
Ethanol does not damage steel. It does absorb water though and that does encourage steel to rust. However the thing that really damages petrol tanks is leaving them empty in damp conditions- outside for example. Your trick with the oil is perfect for a tank that is not being used. I have two tanks here that say it all. One is from a bike that has been stored outside for three years or so - somewhere close to the docks as a guess. It has a hole that you can put your fist through. The other is from a bike that has been dismantled and it has been stored empty and in the loft of a house for fifteen years, in a box, surrounded by bubble-wrap. There is not a spot of rust inside. The actual problen with Ethanol is that it attacks some of the materials that have traditionally been used for lining fuel tanks. It's not kind to a lot of synthetic or natural rubbers too, so fuel pipes and diaphragms in petrol taps and some carbs are in trouble. If you did not know, by the way, Ethanol is not some new fangled chemical that has just come on the market, it's the normal form of alcohol- the same stuff that is in beer and wine that makes you fall over! You could, with a bit of rejetting, run your bike on Vodka or Absolut. The poisonous type of alcohol, Methanol, has more history as a fuel, and if anything, it's more destructive than Ethanol. Methanol runs cooler and gives more power that petrol, though the correct mixture needs to be much richer.
Don't drink petrol though! The alcohol is not the only poison in the blend. Cheers Dave
Drinking Methanol really does make you blind, and not just blind drunk, permanently blind.
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Dave B
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Post by Dave B on Jan 15, 2016 11:02:41 GMT 1
I don't know if I'm the only one on here who actually rode any of the 50cc race bikes on the track. A lot of the old original riders are still around in the classic 50cc club, and some of them still ride the full-on GP bikes, like the Kreidler, but you would be stunned to see how well a bike that used to be an AR50 can go with a modern tuning set-up. My best era was slightly later, with the 80cc class. I never rode the best bike, the LCR Krauser. It had a monocoque ally frame, and a rotary valve motor. I did race a Huvo though. The powerband was narrow- just over 500 revs, coming in around 12500. But actually it was quite easy to ride- all you had to do was relax, keep it smooth and just let it do what it wanted to do- go fast! In all the small classes, you learn not to use the brakes too much- after all, they only slow you down! Even after all these years, it still leaves its mark on my riding style. I wear out front tyres quickly because I just got so used to high corner-entry speeds. On the other hand you could roll back to the paddock after the finish, running at around 5000, and it was as mild as a moped! And yes, you really could buy a Kreidler 50 with pedals to make it a moped, to ride at 16. The Garellis and Gileras were fast, but overall, a good Minarelli engined bike was better than either. That P6 Minarelli engine is still recognisably the basis for the AM50 used in the RS50 Aprilia etc. A race 50 could usually finish a season on one crank, rings would be changed after every meeting, the piston every other one. (Unless you got the mixture and spark timing wrong). Spark plugs- well, on a bad day you might use four in a meeting! Cheers Dave
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Dave B
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Post by Dave B on Dec 5, 2015 10:18:03 GMT 1
Bump started it down the drive, turned round in the road and put it back in the garage facing the other way. I only moved it out so leave more room to sort out the clutch on the Laverda Jota.
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Dave B
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Post by Dave B on Dec 3, 2015 11:05:59 GMT 1
Yep dont disagree lol My phone line is down, I need to know how much of it I am responsible for. My understanding was that from the master socket forward its mine but the master socket, all external wiring etc is theres. Is that the case? I think you are right.
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Dave B
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Post by Dave B on Dec 3, 2015 10:30:10 GMT 1
It would take far too long to tell you of our experience with BT. Their customer relations are the worst I have ever come across. Their technical branch, Openreach, are a law unto themselves, and there is no way to complain when they fail to turn up, or mess up when they do arrive. It took nearly two years to get back money they had charged us for somebody else's broadband, and that included getting the Press and a Government Minister involved, and complaining direct to their CEO. Anyone you talk to at their call centre will promise the earth then do nothing. Nobody will ever call you back, whatever they promise. In a phrase, have nothing to do with BT!. Cheers Dave
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Dave B
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Post by Dave B on Nov 5, 2015 10:22:58 GMT 1
If you have a bench grinder with a wire wheel, you can use the wire wheel to bring any steel item to a good finish after it has been sandblasted. It is not good enough to shine up aluminium items. It would be perfect for a brake disk. Cheers Dave
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