Blackburn Mark

Not as good looking as I hoped and not as ugly as I feared The perforated tube is welded to the outer two extensions (no flexible joints)... the two aluminium rings are pressed on for welding to the aluminium skin. Its a risky strategy... no flexible joint between the flange and down pipe. My welds might not be good for looking at but they are structurally sound Stainless wire wool packing before welding end cap on. With this bracket, the rigid flange and the lightweight canister, I am hoping it is rigid enough not to allow any flex/fatigue. Its much quieter than I was expecting... not as quiet as the original but not miles away. I don't know much about the dark art of muffler design so I am "assuming" the kick-up exit is causing some of the expected "snap crackle & pop" of a straight through, to propagate back into the canister....? I will now upgrade my chances of success to 31% I'm not looking forward to testing this... I have already ordered some 0.7mm stainless sheet in preparation for the canister failing.... but we shall see.

Holy shit, Skye was nice in that one! Getting nostalgic pangs here

Haha... Told you, even the experts don't like extracting broken bolts, its a risky sport Its never the end of the world but nobody likes having to resort to thread-inserts or helicoil inserts... they just don't seem right somehow!

Sticking with the theme: In preparation for replacing this old battered exhaust, I had already fabricated a new down-pipe. Here it is with an ebay-special silencer... it weighs more and is longer than the original so controlling the vibration/fatigue would be a nightmare which is why I hadn't fitted it and after a second look, its going back on the shelf. This is option two, 1mm aluminium sheet I formed months ago. A few problems have kept me shy so far... I'm not so good at welding thin aluminium, aluminium fatigues very quickly and the original stainless exhaust has a straw tint which means the stainless steel has been getting to 340*c / 370*c …. Aluminium loses half its strength at this temp. But I'm desperate and I like a bit of science so here we go... I'm not going to pretend I'm a dab hand with aluminium, you can see how often I dip the tungsten (blind in one eye is my excuse) and I ran a little cold (fear of blowing through) My thoughts are, the old exhaust is a chambered turbo affair so suffers direct contact with exhaust gas. I'm going to try a different tactic, an old fashioned perforated, straight-through with stainless steel wool packing. This ought to insulate the aluminium skin and dampen the pulses on the skin. If I kick the exit up, it might offset some of the extra noise that innocent earthing's have to suffer. Also, I am hoping to stave off bracket fatigue using high rigidity rather than the usual practice of floppy joints. The lightweight skin and packing lends itself to this if I attach/bracket via the straight through tube itself. Predicted fail mode: steel wool burns out in short order (being so close to the exhaust port), skin heats up, fatigues, disintegrates, hits prop, prop launches a blob of molten aluminium into my wing, wing catches fire, I take up playing dominoes Its an optimistic attempt, ill give myself a 30% chance of making it make sense in the long run.

I don't know the laws in Nepal or any schools or school practices. Schools tend to provide equipment. There is no end to study... plenty to be found online. Rules tend to be quite relaxed for foot launched flight compared to other forms of flight but teaching yourself is asking for trouble that can often be avoided. Paramotoring is a very simple form of flight but if you get it wrong, the consequences can be very expensive and that is if you are lucky enough not to hurt yourself.

I couldn't if I tried... The cage hoop is home made, the frame has been straightened, the dog-legs have gussets welded in, the exhaust has more welds than exhaust, the throttle is homemade... if something breaks, ill guarantee iv had my mitts all over it. Its old and heavy but I refuse to surrender

You are asking a lot of yourself there... not impossible "if" you are good at long term plans. Get some training and you will soon see if you are likely to become addicted to the sport, if the sport gets under your skin, then come hell or high water, you will make it work driven forward by your addiction for flight Not everyone has an affinity to explore the full envelope of the sport to the extent of becoming very proficient but you do look young enough to be one of those who may eventually be very proficient. Concentrate on getting your feet off the ground "then" re-calculate the dream from there

Did you use Loctite? Loctite will normally lose its grip with some heat but if that is paint (and not an anodised finish) getting enough heat in there without damaging the finish might be a problem. It looks like you did a good job of drilling that bolt... if it is spot on, you can just slowly up your drill size until you can peal out the thread like a spring but its not a job anyone enjoys, the stakes are high if it goes wrong

I had almost three hours worth of fuel left and I was in the mood for running it dry... I had quarter of a good flight

Having waxed lyrical in another thread about focused stress points on exhausts, I thought I would prove my point AND show how retarded I can be when the mood takes me. Having discovered the spring had broken on the pre-flight today, I chose to nip out the additional slack.... this left almost no flex but I was desperate to fly so what the hell. Looking on the bright side, my welding on the previous fracture was stronger than the base material although looking at the break, the heat affected zone may have hardened....? One and a half hour with not enough flex is all it took. The silencer started clipping the prop... This is where I went full retard, I thought a redundant wire I had tied off had come undone and was clipping the prop so I thought I would attempt to limp home. Bad move, it was clipping the exhaust which fatigued the baffle which came out. The baffle cut one tip off and took a chunk out of the other. I can build and repair anything on this machine dirt cheap... except the prop... maybe its time I made a copy machine and bought some wood. It was a nice flight up until this... I had a 10mph SE over a 10mph NW sea-breeze... tail wind in any direction

290cc.... Are you sure? I cant imagine how they have squeezed that in-between a 57mm stud spacing without going for a very long stroke.

Lol... I get that on a 23m kougar and Bailey V2.... ran like a bastard... no chance! Getting too old for nil winds on a 23m... that shit hurts

I was assuming the strap that you expect to be there was being overexposed and the steel cable was a failsafe... if its not, I don't like the look of the focused stress on the riser or the tubing!

Shorter days become a pain in the ass but you are less likely to be dealing with the complexities of switching wind strengths / direction... swings and roundabouts. The hard part is committing to actually doing it... Once you have pulled the trigger, chances are, sooner or later you will end up in the air and fall in love with the sport.

That's it Andy... rub it in! Us hillbilly types have to make do... On the up side, my dumper truck will do 50mpg in still air

Agreed... my kit, fully fueled is 45kg... debilitating for old legs like mine. Sooner or later I will have to drop the sport... £5000 for lightweight (two stroke) gear is more than I can face without throwing up on my hobnail boots

Lol, yep, sod that when you can get a complete GY6 150cc for less than £200... ill put up with the extra 20kg

You are in a tough spot. I bought an old Baileys V2 that had been in a smash (£1300) so copying and rebuilding was reasonably easy to do so you have that option at your disposal. Building a "ring-roller" is a pain in the ass (but easy to do if you have a lathe)... making the netting was not fun either but almost anyone could learn how its done. I have been flying that for a couple of years now and none of my welds have failed That might be true (and I agree, scarce is good) but in my experience, there are very few who can convert the rather common fantasy of flight into the realities of actually flying without taking the sport "very" seriously... A low IQ head-banger busting barrel rolls in other peoples airspace... Not impossible but I cant see it being common. Even more so for a "self-taught" or "self-builder" where the paranoia is at double bubble

Thought not... a lot of overkill in those, I have one on my V2. That might be the bugger! If that spade goes high resistance or intermittent, I guess it could stress the stator. They are mounted on the crankcase on the V5, lots of vibration. The V2 CDI is mounted on the frame.

Ah, maybe the OP "is" talking about a failed stator.....? Now I think about it, a worn plug, HT lead or bad plug cap would put more stress on all three coils (primary / secondary and the driver) I still cant see how CDI would play any part in stressing those coils so I still cant see it being the CDI causing a recurring problem. On a side note, does the V5 still have a flywheel like the following: The original GY6 flywheels are heavy... I would have thought the V5 would have got rid and installed something "much" lighter for a pull start machine.

That does look very weak! Did you strip to see if the spring was broken? I think the cam is a J300 from Taida but I am not 100% sure.... the J300 is the only decompression cam I have ever found for the GY6

Scratch all that complexity "IF" you are burning out the secondary winding of your ignition coil. If your HT lead (between the coil and spark plug) has gone high resistance (poor quality lead) then it may be that, that is causing the secondary winding to heat up and fail. That would make a "lot" more sense according to Occam and his infamous razor Fit a high quality HT lead!

You have me confused with that statement. This is a reasonably standard GY6 stator... the white coil is the driver for the ignition and all the other coils would be redundant on a V5. I don't have the V5 (I have the V2) but it looks to me that Bailey has made a custom lightweight stator and rotor for the V5 which I "assume" is burning out the ignition coils primary windings....? If this is the case, I would suspect it is possible that Bailey has pushed the limit of the primary coil by designing a higher than standard voltage magneto ignition driver coil and/or using neodymium magnets....? (make starting easier but at wide open throttle the voltage will be high) "IF" it is the case that you are burning out the "primary winding on the ignition coil" (not the stator winding), you would need to reduce the number of windings on the magneto or move the magnets further away (which ever is easier to implement) but like I said, I have not seen the V5 system. I cant see the CDI box burning out your ignition coil but I will have to have a think about it. The CDI is just a timing machine that will open (or shut) the gate between the voltage on the magneto side and the ignition coil so it is the magneto that dictates how much voltage the ignition coil sees and I am assuming that at wide open throttle, it is seeing too much and overstressing the ignition coil. Ill try to dig out a schematic for the CDI and have a ponder

I have also heard of people who forgo the balance cycle for long periods without any major departures in balance but a magneto / regulator system would make me nervous even if I had a plot of the output under all conditions. Even if the voltage never exceeded the nominal pack voltage you would need to be sure that your system couldn't exceed the packs charge current limitations. IF I was going to experiment, I would want that pack mounted in such a way that if it went off like a hand grenade, it couldn't do anything but cost me a new pack

Pretty sure there are only two types and you are after the 6 pin AC type (battery-less ignition) Slightly larger than the DC version (if my memory serves) EBAY: Racing CDI Box Ignition Coil Spark Plug Fit Gy6 50cc 125cc 150cc ATV Moped G7C5U For the sake of £7 its not worth having a heart attack unless you are in a rush to order one from a UK source. Are you sure there is a cdi/coil problem on your machine?