Running methylated spirits in the fuel!

[brendonv]

Well guys since im making a kart with a 2.5hp and not going to have it very long till i get a 5hp+ im going to abuse it and try a few simple things to increase power. My step bro (diesel Mechanic) said, take the baffle out of the muffler, dont do a straight pipe as they need back pressure still. Get a better air filter or no air filter, get higher octane fuel or run a bit of alcohol in the fuel. Then he said try metho since its like 99% alcohol, but im not sure if its harmful to the engine, can i run say 10-20% methylated spirits in the fuel or does it harm the engine?

Ill start with like 5% then increase it, see how much i can get outta a 2.5hp! Running an almost straight pipe, no air filter and 5%-30% alcohol.

Cheers,
From Brendon.v

 

[modelengineer]

Don't worry about back pressure. Put a straight pipe on it.

Oh, and I have no idea about methylated spirits in the fuel. Sorry.

 

[Russ2251]

dont do a straight pipe as they need back pressure

Glad he's not my mechanic.
Back pressure, or the lack of it, won't hurt anything. Slight improvement using a straight pipe may occur as long as governor is not in place.
I doubt you will notice the difference given you have only 2.5 hp to begin with.. Can be proved out with a stop watch. Noise pressure on ears gives illusion of increased power.

Get a better air filter or no air filter

Ever see the combustion chamber/spark plug (and ultimately cylinder walls) of an engine that did not use a filter? Use something.
Unlikely any gains will be realized here also.

higher octane fuel or run a bit of alcohol in the fuel.

My all time favorite!!!
Higher octane fuel does nothing to increase power.
This is just a waste of money. Unless timing, compression ratio, or re-jetting is altered...this does not do anything except to deplete you wallet faster.
If you want proof of this, go to local hobby store and get some model airplane fuel. Has methanol and nitromethane.
Put it in fuel tank and watch what happens.
Absolutely nothing.
Apply any of the above to a 2 cycle engine, then yes, you will see and feel a difference.

 

[jr dragster T]

The alcohol and gas idea will help a bit to keep the engine cooler and help it burn cleaner. In the racing world it's known as "gasohol". I dont see it helping much in that engine. I run 100% in my race engines.

 

[Russ2251]

Oh...I almost forgot. Methanol eats aluminum. Brrr...

 

[jr dragster T]

Yeah Methanol eat's aluminum. Did I mention Alcohol eat's aluminum?

 

[brendonv]

Alrighty i wont do any of that then haha. Once i build the kart ill see how fast it goes (already no, NOT VERY!)but then ill mod it if the price is alright. How do you re jet the carby? Do u just take the jet out n drill it out a bit or do u get a bigger one? How much are cams for the 2.5 horse and how much of a difference will that make?

 

[jr dragster T]

Yeah drilling jet's isnt that hard. Just pull the jet and drill with the according #'d bit. Personally me I like to run Mikuni carb's and I have a freind that has over 1000 jet's for everything so we dont bother drilling and screwing around with that.

 

[trails]

from the sounds of your mods, you will get a nicer sounding engine and maybe a couple more mph. but im no pro. jus my gesitmate

 

[BradenM]

I have a mate who raced 125's in the 80's, and he said they ripped stock air filter's off immediately, cut up a 1.25l sof drink bottle (cut holes in it and adapted it to replace missing air filter) and put panty-hose on it and hey presto, high flow air filter.

 

[brendonv]

good idea, i might try that one day.

 

[jr dragster T]

I'm not sure if I would realy trust that air filter. The Filter pictured (Which is mine for my go kart) is arguably the best in the world.

 

[Kenny_McCormic]

Pantyhose is a very poor filter.

 

[jr dragster T]

Yeah save the panty hose for the women. Or the men if you like it that way.

 

[trails]

def go with a uni. i dont know how to hook one to a gokart but i always used uni filters when i rode dirtbikes. great filters and cheap

 

[ZnsaneRyder]

He told you NO air filter, but don't use a straight pipe, hahahahaha!!!!

Just THE OPPOSITE!!!

Backpressure is a joke. The more flow the better. However, on your intake, you NEED a filter! Just get a better filter or remove any cover on a stock one. NO AMOUNT OF FLOW is worth scoring up your cylinder and hurting your engine.

 

[trails]

filter is a must

 

[ZnsaneRyder]

And to be on the topic of adding something to your fuel, I find that denatured alcohol works great. More low end torque and acceleration.

I use a mouthwash cap to measure, and do 3 capfuls to a tank.

 

[trails]

does this not decrease engine life?
i want to try but i dont want my engine to **** up

 

[Russ2251]

I find that denatured alcohol works great.

Depends on what was used to 'denature' it.
If it's MEK, I might agree.