Carb type and size
- Thread starter Boomanchoo27
- Start date
Boomanchoo27
Member
For gas, never told him I was running e85r
Boomanchoo27
Member
Bingo on to many cooks. I did order a 24mm nibbi with jet kit, but I'm bound and determined to get this mikuni running, one way or another even if I have to carry with me on a run one day.
HOW ARE YOU EVEN EXPECTING IT TO RUN WITH JETTING FOR A DIFFERNT FUEL. YOU'RE SETTING YOURSELF UP TO FAIL BEFORE YOU START. EITHER RUN THE FUEL YOU ARE JETTED FOR OR GET THE RIGHT JETS FOR THE FUEL YOU WANT TO RUN. YOU SEEM TO HAVE A HIGHLY MODIFIED BUILD AND IT'S GOING TO REQUIRE FINE TUNING ON CARB TIMING ECT ECT YOU'VE STEPPED OUT OF THE PLUG AND PLAY GAME. BEST OF LUCK
Boomanchoo27
Member
And you have a pt, I've bought jets from tbparts.com for gas and a 180 is the size of a stick pin compared to the 180 that came with it. Don't give up on me as I'm trying here, I've always wanted to run gasoline not e85 or methanol. I m working the next 5 days so my time of actually working on it is limited until Friday. My next day off.
How much compression are you at? I have no idea why you're brother in law is pushing for the e85 esp if he doesn't even know how to tune the fuel system for it. Methanol is easy enough makes good power and is half the price of race fuel. You definately just need to decide on a fuel and get the JETS for that fuel and go from there.
Boomanchoo27
Member
The jets I have are for gas and that's what I'm going with, he thinks e85 burns cooler and makes more power than gasoline I say not true. Every other post on her is about methanol, I can't walk into a store and buy it so I'd have to order it, correct?
This is the kit I bought.
https://www.tbparts.com/product/20mm-28mm-mikuni-vm-performance-carbs-main-jet-kit/
This is the kit I bought.
https://www.tbparts.com/product/20mm-28mm-mikuni-vm-performance-carbs-main-jet-kit/
Boomanchoo27
Member
This is my full order... I ordered everything I could..
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Boomanchoo27
Member
I thought running rich was bad or is running lean bad...
running lean you will burn your piston up and run hot, running rich you may foul a plug and wont make temp or as much power neither are good but being rich isnt as exspensive
Boomanchoo27
Member
That's true, I'd much rather burn a plug than a piston
Boomanchoo27
Member
I do have another question and that's the emulsion tube or jet tube as it's called in the mikuni, should I order one that I know is for gas or leave the one in it alone and trust jimmy
Probably need a little lesson here to help the decision making process.
Octane is a measure of the fuels resistance to detonation, or preignition.
More octane, more resistance. Fuel burns slower.
87 octane is less resistant than 93.
E85 is more resistant than 93 octane.
Methanol, even more so
The resistance comes at a price of less power available from the same amount of fuel.
This is why, when you fill your flex fuel vehicle with E85 instead of E10, or standard gas, fuel economy suffers.
Since jetting is based on the amount of fuel per the amount of air, larger diameter jets are needed with more octane.
This is based on not making necessary changes to take advantage of the fuels resistance to detonation or preignition.
The jist of this is, don't expect to change fuels without the necessary carb to make this work.
I'm sure your carb supplier has a carb to get you close with the fuel you wish to use.
You can't expect to take a gas carb, or a methanol carb and switch fuels. To many other variables involved.
Most of the answers given in this thread are based on incomplete information.
Your guesses are as well.
Octane is a measure of the fuels resistance to detonation, or preignition.
More octane, more resistance. Fuel burns slower.
87 octane is less resistant than 93.
E85 is more resistant than 93 octane.
Methanol, even more so
The resistance comes at a price of less power available from the same amount of fuel.
This is why, when you fill your flex fuel vehicle with E85 instead of E10, or standard gas, fuel economy suffers.
Since jetting is based on the amount of fuel per the amount of air, larger diameter jets are needed with more octane.
This is based on not making necessary changes to take advantage of the fuels resistance to detonation or preignition.
The jist of this is, don't expect to change fuels without the necessary carb to make this work.
I'm sure your carb supplier has a carb to get you close with the fuel you wish to use.
You can't expect to take a gas carb, or a methanol carb and switch fuels. To many other variables involved.
Most of the answers given in this thread are based on incomplete information.
Your guesses are as well.
Last edited:
Boomanchoo27
Member
Very well said, so let me say this I want to run good ole gasoline, not e85 or methanol, my build is in one of these posts above, so with this being said I will aquire some 87 octane and a few spark cheap plugs to test and tune. I did order a .690 carb for gas and it did run so I know it's a carb jetting knowledge issue. I will figure this out with the knowledge that I have acquired since this post started and get this carb issue done.
I didn't say this before.
Max power from your chosen fuel is being at the ragged edge of detonation, or preignition.
Aerosmith knew what they were talking about.
Living On the Edge.
Boomanchoo27
Member
Ok so with that being said minus methanol, what fuel would you run?