CarlsonMotorsports
Site Supporter
I think he got it running just fine "mint" per original post....still in the dark as to what was the cause though.
L206 with no pulse-new engine
- Thread starter Tonypowerkartsupply
- Start date
Tonypowerkartsupply
Member
Oh Yeah, I got it started that same day. Just was mind boggled to what caused it. I know very little about engines, my father doesn't let me touch them lol. I poured oil into the cylinder and wd40. sprayed wd40 into the carb and after a few pulls it fired up and ran mint. I worked on it for over an hour though. I changed fuel lines, fuel pumps, primed the fuel lines. maybe it was just coincidence after I put oil into the sparkplug hole it fired up. Prob was the needle stuck.
Jimbo
You can fool some of the people some of the time
Dale
You are correct. Yes the breather controls crankcase pressure. That's what it's there for. It is a simple reed valve that lets pressure out when the piston goes down (also blowby) and is responsible for creating a vacuum when the piston goes up.
The valve cover has 2 passages from the crankcase. One is the .200" hole between the push rods as well as the space around the push rod as they go through the plate that the valve cover bolts to. There is also a .200" hole between the 2 lifters just above the camshaft.
The other is the approx 3/8" hole next to the cylinder that connects the valve cover to the crankcase via a channel in the head gasket surface.
You will still get a pulse in the crankcase (to some degree) if the breather is inoperative but depending on how bad it is the strength of the pulse will be diminished to some degree.
You are correct. Yes the breather controls crankcase pressure. That's what it's there for. It is a simple reed valve that lets pressure out when the piston goes down (also blowby) and is responsible for creating a vacuum when the piston goes up.
The valve cover has 2 passages from the crankcase. One is the .200" hole between the push rods as well as the space around the push rod as they go through the plate that the valve cover bolts to. There is also a .200" hole between the 2 lifters just above the camshaft.
The other is the approx 3/8" hole next to the cylinder that connects the valve cover to the crankcase via a channel in the head gasket surface.
You will still get a pulse in the crankcase (to some degree) if the breather is inoperative but depending on how bad it is the strength of the pulse will be diminished to some degree.
Tonypowerkartsupply
Member
My customer who purchased the engine had the same problem. Ran in one race day no problems. raced yesterday, ran 5 laps engine died. brought it to pits, it fired up and ran great. went out again, engine died after 5 laps. Then we couldn't get the engine to fire at all. Changed the carb, same thing. Then tried a new carb, nothing. Driving home my buddy called me and said gotta be in the valve cover. Im going to check this week.
Tonypowerkartsupply
Member
No I'm way beyond that point lol
Jimbo
You can fool some of the people some of the time
I know you said you switched the carb and tried again but the most common reason for not getting fuel into the carb is that the float needle is stuck shut.
If it is stuck the fuel will not move at all from the tank towards the fuel pump or carb. I'll say it again NO FUEL WILL MOVE ANYWHERE! You can pull the rope from now till Christmas and nothing will happen, If the pressure can't get out nothing will move.
Try this:
Pull the fuel line off at the tank and make sure fuel runs out freely. Make sure the tank is vented properly.
With the hose off at the carb pull it over several times and see if fuel moves up the line to the pump and then to the carb.
If it does but will not when attached to the carb the needle is stuck in the seat.
Try putting a little WD 40 in the fuel inlet of the carb and tap on the float bowl with a screw driver.
If that doesn't work leave the carb on the engine and take the float bowl off and free up the needle. It will probably free up when you take the bowl off.
Pull the rope and see if fuel comes out around the float needle.
If it does you just fixed the problem.
Each day when you are done racing drain the float bowl, pull the fuel line off at the carb and plug it. Squirt a little WD 40 in the fuel inlet nipple of the carb. Leave the fuel line off until the next race day.
If it is stuck the fuel will not move at all from the tank towards the fuel pump or carb. I'll say it again NO FUEL WILL MOVE ANYWHERE! You can pull the rope from now till Christmas and nothing will happen, If the pressure can't get out nothing will move.
Try this:
Pull the fuel line off at the tank and make sure fuel runs out freely. Make sure the tank is vented properly.
With the hose off at the carb pull it over several times and see if fuel moves up the line to the pump and then to the carb.
If it does but will not when attached to the carb the needle is stuck in the seat.
Try putting a little WD 40 in the fuel inlet of the carb and tap on the float bowl with a screw driver.
If that doesn't work leave the carb on the engine and take the float bowl off and free up the needle. It will probably free up when you take the bowl off.
Pull the rope and see if fuel comes out around the float needle.
If it does you just fixed the problem.
Each day when you are done racing drain the float bowl, pull the fuel line off at the carb and plug it. Squirt a little WD 40 in the fuel inlet nipple of the carb. Leave the fuel line off until the next race day.
Tonypowerkartsupply
Member
We had the bowl off, cleaned entire carb. Tried everything, at this point we went to the new carb. And still nothing. Not only did I pull the fuel line off the carb i, filled the gas line the blew Into it trying to push has through the pump. And this engine is brand new. It was ran only one day.
Have you tried changing valve covers? Like everyone is saying, the pcv check valve in the valve cover can and will fail, it can be bad on brand new engines even though it is rare. Since the engine has been sitting for awhile, I would try changing it with a new or known good one and see if it fixes the problem, you dont have anything to lose by trying.
