Raptor three alcohol and crank case

Gokart57

New member
Just picked up raptor 3. 5horse Briggs runs on alcohol want to know why alcohol is found in the crank case with the oil?
 
If it's alcohol, it's either getting past the rings or the IN valve guide.
Now, it could be moisture (condensation drawn by the PAG based oil that is popular in karting.)

If it's got a Tillotson carb on it - you can bet it will load the crankcase with fuel in short time at idle. Don't idle an engine with a Tillotson that's been drilled for alcohol.
Stock appearing carb could be a similar problem - tons of fuel on low side.
If it's a stock (or blueprinted) stock carb, you shouldn't be seeing any alcohol in the oil at all.


-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
31 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
There are several reason for alcohol to be in the crankcase.
#1 reason: Idling the engine, There is no reason to idle an alcohol engine. It will fill the crankcase with alcohol with more than you will get in it during a 30 lap race.
while in the grid waiting to enter the track. Do not start the engine until you are ready to enter the track.
Sorry Brian, I just felt like it needed a little more extra exclamation point.
I watched a team start the engine on the stand, then roll it over to the grid. Put in on the ground, Kid put on helmet, gloves and then sat there for about 2 minutes. And probably will complain that the engine lost power because it wore out too soon and then blame the builder for sloppy work.
According to EC Birt, there is no reason to idle an alcohol engine. He suggests that you turn the idle screw out to where it will not idle at all. Then you have to make it run using your foot. That is the way all of my engines are set up.
Even if you have the stock Raptor carb drilled and running on alcohol . It will still do the same thing. Just not as bad as a tillotson.
 
Last edited:
There are several reason for alcohol to be in the crankcase.
#1 reason: Idling the engine, There is no reason to idle an alcohol engine. It will fill the crankcase with alcohol with more than you will get in it during a 30 lap race.
while in the grid waiting to enter the track. Do not start the engine until you are ready to enter the track.
Sorry Brian, I just felt like it needed a little more extra exclamation point.
I watched a team start the engine on the stand, then roll it over to the grid. Put in on the ground, Kid put on helmet, gloves and then sat there for about 2 minutes. And probably will complain that the engine lost power because it wore out too soon and then blame the builder for sloppy work.
According to EC Birt, there is no reason to idle an alcohol engine. He suggests that you turn the idle screw out to where it will not idle at all. Then you have to make it run using your foot. That is the way all of my engines are set up.
Even if you have the stock Raptor carb drilled and running on alcohol . It will still do the same thing. Just not as bad as a tillotson.
Thanks guys yes we were Idling it just after we purchased it kind of admiring the lope of the cam appreciate the info
 
Next question how do you break in a fresh ringed alcohol motor if Idling is a problem do you break it in on gasoline?
 
Next question how do you break in a fresh ringed alcohol motor if Idling is a problem do you break it in on gasoline?

low/medium rpm under load - constant, then varying rpm - load, then coast for 10 minutes.
Change oil.
Repeat, extending the time that you are on throttle, thus increasing peak rpm for 10 minutes.
By the time you are at the end of this 10 minute session, the engine should be ready to be raced hard.
Change oil and race.


It's especially important to change the oil often early on in an engine's freshen-up cycle. Keep in mind that these engines do not have an oil filter.
We do offer magnetic oil drain plugs which help significantly, but still, you can't change the oil too much in these things.


-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
31 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
low/medium rpm under load - constant, then varying rpm - load, then coast for 10 minutes.
Change oil.
Repeat, extending the time that you are on throttle, thus increasing peak rpm for 10 minutes.
By the time you are at the end of this 10 minute session, the engine should be ready to be raced hard.
Change oil and race.


It's especially important to change the oil often early on in an engine's freshen-up cycle. Keep in mind that these engines do not have an oil filter.
We do offer magnetic oil drain plugs which help significantly, but still, you can't change the oil too much in these things.


-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
31 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
Thanks
 
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