400ccStroker_shee Posted March 28, 2007 Report Share Posted March 28, 2007 I was thinking of switching from gas to alky, what do I have to do? Does is require different porting from an aggressive dune port? Carbs? Anything else? I can use all the help you guys can hook me up with. Quote Link to comment Share on other sites More sharing options...
dajogejr Posted March 28, 2007 Report Share Posted March 28, 2007 I was thinking of switching from gas to alky, what do I have to do? Does is require different porting from an aggressive dune port? Carbs? Anything else? I can use all the help you guys can hook me up with. First things first. How and where do you ride your bike? If you want to trail ride....scratch alky. You'll be going through twice as much alky and oil as you do gas. You'll need to supply more alky to the motor, here are some common ways to do that... 1. Remove a float 2. Buy a dual feed pingel valve 3. Buy larger float bowls, holding more volume 4. Fuel pump setup (mechanical or electrical) You'll need to install powerjets on your carbs, too...think of it as an externally adjustable main jet...which dumps more alky into the motor as the RPMS raise. Alky responds to higher compression and more advanced timing as well. Also...you'll have to get used to a purge routine. In other words...once you're done riding for a weekend, you have to hook up a gas tank (external, auxillary, etc.) and run gas and premix oil through your lines, carbs and motor. Alky sitting in carbs and a motor can cause parts (gaskets and seals) and metal parts to rust internally. And...you will need bigger carbs. It will run on stockers...but, because of the amount of alky you need to flow, bigger carbs are a much better idea... Are you ok with all of that? If so...let's move on! Quote Link to comment Share on other sites More sharing options...
badassbanshee479 Posted March 28, 2007 Report Share Posted March 28, 2007 dont forget to factor in a new top end to the equation. There is a learning curve to tuning alky, and you will probably melt a hole in a piston a couple times before ya figure it out. Quote Link to comment Share on other sites More sharing options...
lowriderb Posted March 28, 2007 Report Share Posted March 28, 2007 i have ran stock carbs converted to alcohol on my 350 stock cylinder on up to the 38mm carbs i ran on my 4mm cub.. you do not go through twice as much oil as you do with gas, i have mixed mine at 32:1 ratio since i started running alcohol, think of it like this, there is twice as much fuel being put into the cylinders that would equate there would be twice as much oil now too, not premixed just becuase of what is in the fuel already.. you do have to purge your bike, some people go overboard with it and purge every day after riding, this i believe is not needed by a long shot.. go riding for the weekend, purge the bike when you get home (i normally purge my bike with 97pump fuel at 32:1) the carbs do need power jets in them for tuning it in.. the power jets are auxillary jets put on the filter side of the slide in the carb.. there are a few different types out there from some that use actual jets in them to adjustable ones that have a needle type screw in them.. and aggressive dune port would do fine on alcohol.. just keep an eye on your gas tank.. Quote Link to comment Share on other sites More sharing options...
dajogejr Posted March 28, 2007 Report Share Posted March 28, 2007 i have ran stock carbs converted to alcohol on my 350 stock cylinder on up to the 38mm carbs i ran on my 4mm cub.. you do not go through twice as much oil as you do with gas, i have mixed mine at 32:1 ratio since i started running alcohol, think of it like this, there is twice as much fuel being put into the cylinders that would equate there would be twice as much oil now too, not premixed just becuase of what is in the fuel already.. you do have to purge your bike, some people go overboard with it and purge every day after riding, this i believe is not needed by a long shot.. go riding for the weekend, purge the bike when you get home (i normally purge my bike with 97pump fuel at 32:1) 2 things. Most people run their alky from 20:1 to 28:1 premix ratio. And even if they left it at the common 32:1 mixture....they'd still be going through more oil due to you're be burning twice the amount of fuel (Alky) I agree on the purging. I wouldn't leave it in there for a long time, but...if you have a long weekend of riding...and ride it every day, then purge it at the end of the ride OR when you get home, I'd say you're gonna be fine... I won't be purging mine daily...no way! the carbs do need power jets in them for tuning it in.. the power jets are auxillary jets put on the filter side of the slide in the carb.. there are a few different types out there from some that use actual jets in them to adjustable ones that have a needle type screw in them.. and aggressive dune port would do fine on alcohol.. just keep an eye on your gas tank.. Yep yep!!! Quote Link to comment Share on other sites More sharing options...
400ccStroker_shee Posted March 29, 2007 Author Report Share Posted March 29, 2007 2 things. Most people run their alky from 20:1 to 28:1 premix ratio. And even if they left it at the common 32:1 mixture....they'd still be going through more oil due to you're be burning twice the amount of fuel (Alky)I agree on the purging. I wouldn't leave it in there for a long time, but...if you have a long weekend of riding...and ride it every day, then purge it at the end of the ride OR when you get home, I'd say you're gonna be fine... I won't be purging mine daily...no way! the carbs do need power jets in them for tuning it in.. the power jets are auxillary jets put on the filter side of the slide in the carb.. there are a few different types out there from some that use actual jets in them to adjustable ones that have a needle type screw in them.. and aggressive dune port would do fine on alcohol.. just keep an eye on your gas tank.. Yep yep!!! I ride sand only. my mods are an stock bore, aggressive dune port, +6 timing, pro design coolhead with 21cc domes, for right now I have fmf fatties with powercore 2's, but I was thinking of switching to shearers or cpis. Thanks guys if you can help me with what type of carbs would be best for me and other mods that would help this thing scream!!! For right now I just want to keep the bore and stroke stock!!! Quote Link to comment Share on other sites More sharing options...
badassbanshee479 Posted March 29, 2007 Report Share Posted March 29, 2007 bump up the compression, and get your self some 35pwks. Then get with a reputable builder and have them converted over to alky. They will know where to set your mains and dumps at, and they will also install the power jets for ya. I had FAST do mine and they work great! Quote Link to comment Share on other sites More sharing options...
dajogejr Posted March 29, 2007 Report Share Posted March 29, 2007 Is your crank welded? If not...get that done. Otherwise, you have a great base for an alky bike!! I'd say 35PWK carbs...you could get 39's...but, I think you'll be happier with the overall output of 35's on alky. If you do get Shearers...then you're gonna be a pretty much all top end motor. Then get 39's. I'd go with 19 or 20cc domes as well, alky likes a bit more compression!! Again....weld that crank!! Ha...that's funny JT...same time, same stuff... :biggrin: Quote Link to comment Share on other sites More sharing options...
badassbanshee479 Posted March 29, 2007 Report Share Posted March 29, 2007 great minds think alike! :yelrotflmao: Quote Link to comment Share on other sites More sharing options...
400ccStroker_shee Posted March 29, 2007 Author Report Share Posted March 29, 2007 (edited) Is your crank welded? If not...get that done. Otherwise, you have a great base for an alky bike!!I'd say 35PWK carbs...you could get 39's...but, I think you'll be happier with the overall output of 35's on alky. If you do get Shearers...then you're gonna be a pretty much all top end motor. Then get 39's. I'd go with 19 or 20cc domes as well, alky likes a bit more compression!! Again....weld that crank!! Ha...that's funny JT...same time, same stuff... :biggrin: The crank is trued and welded, so it sounds like 35 pwk's and still deciding on the pipe. one more question, i heard with mukini carbs they can go back and forth between gas and alky? Edited March 29, 2007 by 400ccStroker_shee Quote Link to comment Share on other sites More sharing options...
r/atvshee Posted March 29, 2007 Report Share Posted March 29, 2007 How much does alky cost these days. Kinda tossing around the idea of switching to alky lately. Quote Link to comment Share on other sites More sharing options...
dajogejr Posted March 29, 2007 Report Share Posted March 29, 2007 The crank is trued and welded, so it sounds like 35 pwk's and still deciding on the pipe. one more question, i heard with mukini carbs they can go back and forth between gas and alky? Correct. Some 35.5 TMX Mikunis are a great alky setup too. Dump tubes (where the needle slides down into the main) needs to be drilled. You can replace this dump tube on most Mikuni carbs. You can not replace this on Kehins. I think T5s would be a good all around pipe if you're gonna dune...CPIs more so....but Shearers if you're gonna drag more than dune. To be honest, if you're gonna go alky, it should probably be because you're gonna drag race 75% of the time. I don't know too many people on meth that just plan on bouncing around the dunes with the occasional race... How much does alky cost these days. Kinda tossing around the idea of switching to alky lately. Usually, it's half the price of race fuel from the pump...but, you go through twice the amount and more oil too...so, no cost savings really. Just more power, from 5 to 20 percent, roughly of course. Quote Link to comment Share on other sites More sharing options...
cam2 Posted March 29, 2007 Report Share Posted March 29, 2007 if you're going to change pipes, do it right the first time and get the shearers. the cpi's would be another good choice, a better choice than the T5's. you won't gain much if anything at all by going with the T5's over the fatty's you have now, maybe shift the power band slightly. Quote Link to comment Share on other sites More sharing options...
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