How to build an engine.

[lingeringstin...]

Here's one I decided to make earlier:

https://vimeo.com/69509292

An informative instructional in several episodes.

Search Vimeo for "stinkybob" and be made aware.

[Bunny Lingus]

Excellent work my man! You are a true shed head of legendary proportions. What happens with that SU carb is what I wanna know...
____________________
Bunny Lingus & The Flipside Faggots

[Aff]

You seem like a proper nut case.

Very entertaining though.

:edit: The fuck was that at the end of episode 3!
____________________
Current Bikes:Honda 929RR Fireblade, Honda CD200 Benly (Project), Stomp Z2 140
Electric Bike Project

[Bunny Lingus]

I'm bumping you man! Spill some beans on the SU & the diesel mix bro. I'm interested. I can see how it works to replace the 2t oil but why? Do you get more mpg? Why with the SU? Tuning?
____________________
Bunny Lingus & The Flipside Faggots

[RhynoCZ]

Great stuff.
____________________
'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[lingeringstin...]

I'll explain it all later today. It's a bit complicated but it works GREAT.

[Jenks]

oh no! Rex is here
____________________
1978 MZ TS 250 1 Supa 5
1992 yamaha fzr1000 exup
1998 aprilia af1 sintesi

[lingeringstin...]

Just testing how to upload pics here. If it works then I'll EXPLAIN the carb.


As usual absolutely NOTHING on computer is easy or even works right.

[Aff]

[.Bishbash.]

Bloody awesome
____________________
Current bike - GSX-R1000 k8

[The Shaggy D.A.]

...and man became aware of THINGS.


____________________
Chances are quite high you are not in my Monkeysphere, and I don't care about you. Don't take it personally.
Currently : Royal Enfield 350 Meteor
Previously : CB100N > CB250RS > XJ900F > GT550 > GPZ750R/1000RX > AJS M16 > R100RT > Bullet 500 > CB500 > LS650P > Bullet Electra X & YBR125 > Bullet 350 "Superstar" & YBR125 Custom > Royal Enfield Classic 500 Despatch Limited Edition (28 of 200) & CB Two-Fifty Nighthawk > ER5

[ForestRunner]

These videos are strangely compelling
____________________
Slowly learning...
CBF125 Red (Stolen) -> CBF125 White -> 1999 Hornet

[lingeringstin...]

OK, I still can't get the photo postings to work so for now here's The Poop about the carb if anybody's interested:




Years ago I worked at a wee two man bike repair shop out of a small unit on some dire industrial estate in South London. In between the scant customer work we spent entirely too much time experimenting on our bikes and things.

One day the other bloke from the shop dug a discarded 1.5" SU out of the skip at one of one of the neighbouring car repair places and handed it to me and said:

"Bet you'll never fit THIS to your bike."

Fighting words indeed. After much and lengthy experimentation I managed to cobble it into the best carb I've ever had, mostly by drilling holes in it and throwing bits of it away.

I don't use two stroke oil, I just mix one liter of diesel to a gallon of petrol. Been doing it for like 15 years and the bike loves it. However, it does make the fuel a bit thicker so if this mix is to run with a normal carb you should to use a bigger jet or raise the needle.

This SU carb has no actual "jet" to speak of, and no convoluted airways (at all) so it's basically just a slide, a needle, and an adjustable hole, and once you get the right taper of needle (and there's about 300 of them to choose from) it's just a matter of adjusting the jet tube up and down until it runs right.

Early on in the experimentation I removed the butterfly gubbins from the carb and attached the cable through the middle of the slide transforming it into a cable pull carb a bit like a giant Amal. It didn't run for shit.

Pulling the slide up in it's sealed housing by cable meant escaping air puffed down around the edges of the slide into the carb when you opened it which caused chaos inside the carb so the engine just spluttered and died the moment you twisted the throttle.

I had to drill some holes in the top of the slide housing thingy to let the air out and in as the slide went up and down and fitted a stiffer spring from another carb. Then it worked fine.

Taking out the butterfly gubbins also meant there was no way to set an idle now, so I just ran it like that. It was a bit like some old dirt bikes used to do. When the slide closed fully, it just killed the bike so you always had to blip the throttle to keep it idling at lights and things but that was no big deal as it soon became second nature to do this.

Then one day my mate at the shop said "Why don't you just introduce an air leak into the carb and see it that makes it idle?"

There followed one of those "why didn't I think of that" moments, so I drilled a tiny hole in the engineward side of the slide and it worked. I had an idle!

Unfortunately the hole I'd drilled in the slide was a bit too big and the idle was high so I filled it up with Araldite or something and decided to make an adjustable air leak. Luckily the carb had an unused vacuum hose thingy that fed straight into the carb body after the slide which I figured was a convenient place for an air leak.

So I drilled a small hole in a bit of plastic tube (discarded beer line from a pub) and screwed a bolt in the end to make an adjustable air leak and it worked.

Even though the slide might be all the way down, the needle doesn't actually stopper the jet tube hole completely. There's always going to be a bit of fuel seepage around the needle in the hole, so it makes sense to add a bit of air and, with the right needle taper, suddenly you get an idle- without an actual idle circuit! No tiny idle jets or airways to clog or anything, it just works. The simplicity appealed to me.

I tried running it on meths, alcohol, paraffin, paint thinner, vodka, unusual explosive gasses and all sorts of mixtures thereof, some injected into the crankcase or carb inlet for go-faster appeal and fire hazard, before I finally settled on the simple solution of premix diesel for every day use. Simple and cheap.

The SU carb's jet tube is easily adjustable by way of a spring loaded nut on the bottom of the carb and I can reach down and twiddle with it on the fly if need be. This way I can adjust the fuel mixture between exceptionally frugal for fuel economy to ultra rich for belting down the motorway. But most of the time I just leave it at a happy medium which gets a decent speed and about 80mpg.

Also without the butterfly gubbins there's no choke of any kind and my two stroke engine NEEDS choke to fire up from cold, so to start the bike I have to get on it and lean it over a bit to the right so the side mounted fuel bowl comes up a bit and then flip the throttle open and closed about 13 times which causes a little bit of fuel to sprinkle into the carb off the needle as it goes in and out the jet tube hole. This little bit of flooding is just right to then kickstart the bike, a similar sort of effect to the old Amal firestarter/dribbler they used to employ on old Brit bikes. Crude but effective.

I don't use any sort of air filter, just a long bellmouth arrangement that keeps the oily spew in and sucks up birds and small dogs as I go down the road. Rain just makes the engine run even better, which is precisely what you DON'T need with that handling and those brakes on wet roads but it's all part of the charm of this bike, which is why I sold my CBR6 and kept the MZ. The MZ costs about five quid a year in upkeep and takes me anywhere I need to go including around Yerp, and is so mechanically simple it can be fixed with twigs and rocks at the Siberian roadside if need be so I haven't seen the back of a recovery wagon for about 20 years with that bike.

At the moment the bike readily goes along at the heady breakneck speed of a mile a minute with ease and can, were one so recklessly inclined, go much faster. In the past when it was unencumbered with such frivolities as lights and mudguards and stuff it occasionally hit speeds of three figures on a track, something it's entirely unsuited for in it's current configuration as a road bike.




Carb pics may or may not be below:




https://www.imagebam.com/image/48efc9326794013

https://www.imagebam.com/image/e19e34326794153

https://www.imagebam.com/image/c84409326794221

https://www.imagebam.com/image/6e70cb326794306

https://www.imagebam.com/image/264305326794420

https://www.imagebam.com/image/e499d6326794491

[The Shaggy D.A.]

Where's the "Way fucking cool" rating when you need it?
____________________
Chances are quite high you are not in my Monkeysphere, and I don't care about you. Don't take it personally.
Currently : Royal Enfield 350 Meteor
Previously : CB100N > CB250RS > XJ900F > GT550 > GPZ750R/1000RX > AJS M16 > R100RT > Bullet 500 > CB500 > LS650P > Bullet Electra X & YBR125 > Bullet 350 "Superstar" & YBR125 Custom > Royal Enfield Classic 500 Despatch Limited Edition (28 of 200) & CB Two-Fifty Nighthawk > ER5

[Bubbs]

Man that made me laugh.
____________________
Life begins at the end of your comfort zone.

[Jenks]

and we ALL know what the MZOC think of you Rex!
____________________
1978 MZ TS 250 1 Supa 5
1992 yamaha fzr1000 exup
1998 aprilia af1 sintesi

[Bunny Lingus]

Well I love shed head innovation me, whether its out of necessity or circumstance. There is something infinitely cool about taking a vehicle & tailoring it to your own personal taste, especially when there is no precedent. Building a streetfighter is cool but its a well worn path. Customising is mostly form over function. Dude, on the other hand, has done something remarkable & unique. I have seen race prepped MZs before but this is the biker equivalent of Punk Rock - left field DIY work in progress which totally suits the man's character. There is more quirky personality oozing out of that bike than most people will ever dream of & I think its sublime. Top kudos fella!
____________________
Bunny Lingus & The Flipside Faggots

[ForestRunner]

Finally watched all the parts.
I have recommended it to a few people with the phrase "You'll either love this or wonder why the hell am I watching it"
Personally I think it's great, as is there bike.

My 125 is cared for in the pampered way that is diametrically opposed to the MZ in question.
BUT, that's only because I intend on selling it on for a minimal loss when I do my tests.

There's a lot that speaks to me about keeping something running well with what is available and to hell with aesthetics
____________________
Slowly learning...
CBF125 Red (Stolen) -> CBF125 White -> 1999 Hornet

[ForestRunner]

Oh, and who doesn't like hammers
____________________
Slowly learning...
CBF125 Red (Stolen) -> CBF125 White -> 1999 Hornet

[lingeringstin...]

You say you watched all the parts? Blimey. You deserve a medal...

Thank goodness it's all CGI and none of that was real.

[ForestRunner]

I worked out how to describe it now.
It's what Captain Beafheart would have made if he had been into bikes and video
____________________
Slowly learning...
CBF125 Red (Stolen) -> CBF125 White -> 1999 Hornet