does any body out there know how many parts per gallon a person can mix for a four stroke machine before the mods or constant cleaning is needed?

 

I think you're talking about mixing alcohol and gas?I've heard that is a bad idea.Not sure though.I use alcohol in my banshee.It is more work than just using gas.You should always purge it at the end of a day of riding,I also drain the tank and get rid of the alcohol I did not use.The alcohol needs more compression,the timing needs to be advanced,larger fuel line,etc...

 

what mods were needed to run the alc. and what sort of increase was there in power?

 

I had to have increased compression(shaved head),Timing had to be advanced(timing plate +8 degrees),I have a dyna ignition for increased spark and is left on the stock timing setting,I run a br9es plug(yours will be different).I already had porting,K&N filters.I switched from stock carbs and T-5 pipes to shearer in-frame pipes and 35mm keihin carbs that were converted to alcohol.With the different pipes and carbs it picked up alot.It pulls hard on topend.Make sure you get a very good set of clutches to handle the extra power.I need another set now.I was at little sahara and having clutch problems.When it would actually not slip,it would feel like it would keep pulling forever.It does require more work for maintaining.Purging the bike after rides,empty the tank,etc...I use benoil with my alcohol.I know you don't have to mix your gas and oil.I do.I left some gas and oil in my tank one time for about a week.When I checked it,it had all kinds of stuff floating in it.That's why I get rid of the alcohol I don't use.It was probably the oil that broke down in the gas,so you most likely won't have that problem.I raced some YFZ's with hi-compression,porting,pipes,and alcohol.They run really good.I was very impressed with them.

 

thanks for the info. very much appreciated[img]i/expressions/face-icon-small-smile.gif[/img]

 

It seems like you're pretty close to getting it ready for alcohol.You already have a hi-compression piston,you're going to get a hotter ignition(It might be able to advance it enough for alcohol,but not sure),so you should be close.You might PM, THEBOM.He builds some insane DS's.I think he normally burns gas,but he might be able to tell you more or tell you someone who can.He really favors the 4-strokes.

 

thanks[img]i/expressions/face-icon-small-wink.gif[/img]

 

You're welcome.

 

You can mix alky with petrol (gas). Every 10% increase needs a corresponding increase of 12% jetting (roughly for a start). 10-20% shouldnt need purging after riding or racing for the day. An added top end lube would be helpful though. Also keep the container sealed up tightly and keep the fuel cap vent hose plugged so the fuel wont be contaminated with water. Alky is very hydroscopic and will draw moisture if left open. Bubba

 

thanks. i also know that it actually decreases your octane levels ,so is a higher octane of fuel needed or is this the whole point?