OzVMX Forum
Clubroom => Bike Talk => Topic started by: jimg1au on March 06, 2008, 06:41:51 pm
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hi
i am building a pre 75 mx360 slider and would like to run the motor on methanol.can any one tell me the rule of jet increase for running methanol.running big 2 strokes on methanol gives them a boost to match the japs and jawas and other 500cc bikes
cheers
jimg
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Comp over 14.5 to start, biggest carby you can fit and take the main jet out and run a 5/16ths drill through it. Worked for my old 360 ;) tim
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There is a proper formula for it but i can't remember it exactly, no doubt someone will know. Increase the flow through the mainjet by about 300%, i used number drills 30, 31, 32, etc and ran a 80 pilot jet and drill the needle jet bigger than the main jet also.
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After a days use run 98 octane thru the motor to stop it from rusting out the internals ;)
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where might one stumble across said methanol and will it send finances crashing? just curious is all, good ol' pump fuel for this weekend :P
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Doc methanol will hit you pretty hard in the pocket and your bike will guzzle it 3 times quicker than petrol. Plus fair bit of stuffing around to get it jetted right, and will melt a piston in a few seconds if too lean. Used to get it from shell depots.
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But it does sound sexy dont it doc ....
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Petrol will melt a piston in a few seconds if your to lean.Ask around the speedway blokes they diminish supplies faster than a fleet of Hummers outside a private school.
Everything needs to be BIG, spark,fuel tap, breather, fuel line, needle and seat, jet, thin needle, run as much compression and advance as possible to get the shite to burn.Buy a few extra pistons and your away.It can be your foray into tuning Doc.
Me I would take Elf 124 over it anyday, but no doubt you can get em going on it.
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Doc Lozzas ELF is the go! really! Tim ;) Methanol is real good at turning motors, carbies to goopy stuck blobs as mentioned if not cleaned out, oh and never try it in any fibreglass tanks! you can have deadly serious chemical reactions. >:( Just sneak a bit of R30 in with the Elf to make a heady scent MMM)
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Elf 124? What is that and where do you get it? Is it something someone seeking to make a bike go good at dirt track would like to have?
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Elf 124, using that would probably be illegal so I wouldn't recommend using it ;) You could use it on a practice day though!!! A well known racer here got a hold of a drum at the time of the Eastern Creek GP's and put a tankfull in an RGV, the effect was 'instant TZ' without changing anything.However if you get it on bare skin it will 'burn' and a solid whiff of it will make you pass out.If that doesn't make you fall over the $9/l purchased in a 50 litre drum might.
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mmmmm..for as nice as all this performance sounds I think I'll stick to pump fuel ;) my neighbor used to run his dirt track TM and speedway midget on methanol when I was a kid but he'd still finish at the tail end :-\ obviously an expensive little exercise..
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Methanol is tricky in two strokes, jetting will change with conditions on the day (temperature, altitude etc) i know of a sidecar racer (ex aussie champ on MX & Dirt Track) who had the brilliant Ray Fisher set his KX500 power Dirt track chair up on Methanol (or "fuel" as the old boys call it) it took a lot of development time and lots of lunched engines, in the end Ray put a thermostat from an outboard in the water cooling lines to stop cold siezures and finally got it jetted, the thing was a rocket (i swung on it for 1 meeting, never again).
i too considered it for my CR250 20 years ago for dirt track events and i was going to get a tuner to assist, he asked me one simple question "are you prepared to lunch 3 or so motors til we get it right" my answer was a "no" due to the expense. this question is still relevent today. if you need more speed in your aging VMX days its more than likely you need to twist the throttle more !
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Lot's of folks reckon they've got the perfect methanol jetting formula but in the end it's an inexact science that is best sorted by starting with the biggest and working down. The 34 Amal Mk2 on my 'DT1 from Hell' started its life on a Weslake Speedway bike. To start the jetting process I bolted it straight on, using the stock Weslake jetting. The bike performed so well I never changed another jet. For the rest of the bikes racing life the stock Weslake jetting did the job beautifully. My theory after that experience is that a 250 2 stroke is roughly the same jetting as a 500 4 stroke. At least it's a starting point. A 360 would be a bit bigger again on the main I'd presume.
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I don't know how Elf 124 is to jet for but it'd want to be easier than the VP C14 I used in my 250 Maico at the '99 Dirt track Nats. We had the 250 on the dyno for days trying all sorts of jetting, oils, pipes and even switching from Bings to Mikunis and back and while we finally got it pretty right using the stock 36mm Bing and a Wheelsmith pipe, moving the back wheel HP from 18 up to 29, the cost was extremely high running temperatures and having to run it as lean as shit to run clean and produce horsepower. The bike hooted and was only beaten for the title on a points countback by Peter Lees awesome Methanol burning ported Elsinore but it cost me a motor in the end. I rebuilt it and ran it on Methanol after that and it ran as well if not better but with no reliability problems. Granted that was nearly 10 years ago so racing fuel may have improved a bit since then........Why would Elf be ilegal for Dirt Track Lozza? Does it have a nitro methane content?
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Any developed 2T engine will be effected by changes in Relative Air Density Hoony, methanol a bit wider margin than petrol.If you use an Exhaust Gas Temp probe and a Cylinder Head Temp probe you might have a light seizure but never lunch an engine.With these it's possible to 'see' detonation/pre ignition setting in.
Firko saved me from another boring post,I don't have the MoM here but IIRC you should have 98 ULP.Trust me that Elf 124 is like nothing else,the secrets are in the ignition and cylinder head, you will do similar things as with alky, and see similar results and then some more because it burns faster than methanol
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ah well, back to the mothballs ;) 1 lump or 2?? :D
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i though mothballs changed the formula and that idea died a sad death , so to speak ?
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Hi guys, Talking of elf fuel, this is what I use in my 74 cr125m, a 98 octane with elf 2 stroke oil.
I have been using it for years with my kids dirt track bikes, and would recommend to anyone, gives longer engine life, burns cleaner, is expensive at $4.00 a litre.
For best results you need to machine the head and set up the squish band,then with the jetting go up a size in pilot jet, and middle clip on the needle, with the main jet go up and up and up and up, till it falls on its bum, then go back a size.
elf is great fuel, awesome out of corners, but you need to set up the head,
Graeme, the TM dont need more power,I cant keep up if you need more power!!!!
Need to find out more ring Aksel, at AXLE MOTORCYCLES, ACT 62820065
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Oh dear else you should go back and read some old posts and learn ::) the fuel you use makes no difference whaever so ever .............apparently ;D ;D ;D ;D ;D ;)
124 would be the same but X 10 I found BFK 98 a bit 'finnicky' on the needle especially 1 clip it felt like it would seize go down one clip and it would blubber away, went back to avgas.Might have another go one day.
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i run methenol in both my elsinores it cost me $220 for a 44 gallon drum i run it at 30:1 with castrol m. theres more to running than just changing jets, you have to get a lot of things right or it will cost you.
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mmm..I ran 91 octane caltex on saturday, I wanted Vortex 98 but I stuffed up at the pump ran with my mistake costing a considerable $13.60 for 10 litres..this and TTS at 30:1 served me well..burnt a nice light brown/tan colour and didn't run overly hot considering the relativity new engines and high rpm..power may have been a little down to the front runners but not enough to warrant a change in fuels or jetting..the under gearing and lack of control was more of an issue ;)
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$220 for a 205 litre drum!!!! ;D where did you get that!!!! please!
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At that price might rum my hilux on the stuff, Imagine the look on the guy with the clubsport as I smoke him in my 2.7 litre workmate.
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Hi guys,
I get 20 Lte's for $60 from ET Racing Fuel. Seems OK.