Looking for some ideas here hopefully.

I replaced the fuel lines with Gates, replaced the fuel filter and hoses on the motor as well.  The hose going to the carbs is slightly pinched, but I do not think it's hindering it atm.  Purchased a carb kit and replaced all 3 carbs.  

 

Here is the problem I am having.

Before I cleaned the carbs and replaced with a new kit there was some fuel leaking out from the bottom carb.  I have since replaced all the carbs with new parts with what was in the kit.  There is still a leak of fuel from the bottom carb and it appears it might be coming from the back side and leaking out the front.  When I replaced the bowl and float I made sure it was level and between 28-41mm when hanging upside down.  I thought about switching the bottom carb with the top to see where it leaks then.  Anyone have ideas on where to start?

 

thanks!

Not sure I fully understand you problem.  When you say leaking out of the bottom, are you talking about inside the throat/venture or are you talking about off the bottom and dripping down. 

On those carbs, do they have the plastic bodies and bowls or are they aluminum.  The plastic ones are really bad about warping and distorting to the point they don't seal around the bowl gasket.

Hey Way2slow,

 

It's leaking off the bottom and dripping down at a slow steady pace.  Here is a pic of what it looks like.  I can get you a picture or video later today to show the exact problem.  I know the previous owner had a 5/16 hose going from the fuel filter to carbs and the fuel connector (fuel connector was 3/8 however and they must have really had a hard time putting that 3/8 plug into a 5/16 hose).

 

ty

If the motor is sitting where the anticav plate is level with the ground and it's leaking gas out of the carb, unless there is a defective fuel bowl or the main jet access plug is leaking, it's leaking by the needle and seat.  There is a vent hole that's it's probably coming out of, but it can only do that if the bowl is over filled.  It won't even leak around the bowl gasket if the float level is right and the needle is closing off in the seat.  The short version of what I just said, sounds like it's leaking by the needle and set. 

Make sure the float is not bad and filled with gas and check the manual on setting the float level.  You said you checked it but did you check the height. It can be level but sitting too far down, when held upside down.  That raised the fuel level in the bowl enough it could be over filling.  Could just be a bad needle/seat. 

Just remember, if the bowl doesn't have a crack or flaw in it, and the plug in the front is not leaking, it can't leak gas if the float/needle/seat is doing what it's supposed to do.

Thanks for the info.  I have created a video for you to look at.  I switched the middle and bottom carb out and it still does it on the bottom carb.  The middle does not leak now, however it was leaking before when it was on the bottom.

 

I should have taken a pic of the gas I bought last week.  I got some of the gas out in a jar and you could see it had a ton of water in it.  This was ethanol free gas btw.  I went to shell a few minutes ago and got 90 gas and after mixing the oil, it looks clean.  I know this was not causing the spewing of gas out, but I cannot even imagine how the motor was running with that gas in it before.

 

Also, this line is just hanging and do not know what it's for.

 

Video

 

 

 

What I saw, if what you are talking about is not a leak.  It looks like it's spitting fuel out the pull over orifice, the hole in the center at the top of the carb.  Two strokes always have small blow back through the carbs, that's just part of the way it works.  However, that's excessive.  That looks more like a possible bad reed or reed plate gasket, or bad recirculation valve.  

If you hold a piece of paper close to the carb venture while it's running you will see gas collecting on it, or hold a flash light at an angle in very low light you will see a mist, that's normal.   However, that bottom carb is not normal, but that's not a carb problem or fuel input problem.  That's behind the carb. 

57 minutes ago, Way2slow said:

What I saw, if what you are talking about is not a leak.  It looks like it's spitting fuel out the pull over orifice, the hole in the center at the top of the carb.  Two strokes always have small blow back through the carbs, that's just part of the way it works.  However, that's excessive.  That looks more like a possible bad reed or reed plate gasket, or bad recirculation valve.  

If you hold a piece of paper close to the carb venture while it's running you will see gas collecting on it, or hold a flash light at an angle in very low light you will see a mist, that's normal.   However, that bottom carb is not normal, but that's not a carb problem or fuel input problem.  That's behind the carb. 

Thank you for the input!  What would you start looking at behind the carb?  Here the 90 ethanol free on the right and new gas on the left, both are mixed according to 50:1

 

would you think it could be the gasket plate to manifold or the manifold intake itself?

 

ty!!

This is a case where you probably need to do a crankcase leakdown test, but that's probably beyond your capacities.  I haven't worked on one of those three cylinder motors in ages, even though I have one under my shed.  I'm trying to think of some way you can pressurize the crankcase for that cylinders crankcase to see if it blows back excessively through that carb.  Something short of just pulling the intake to check it.  Do your homework on recirculation valves, where they are located and how to test them.  As fuel passes through the motor, there are areas that it tends to separate from the air and puddles.  the recirc valves let the engine siphon that fuel and feed it back through the intake.  If one is bad, it can cause similar problems or make an engine run rough.  Reeds and reed block gasket is a prime candidate for your problem.

 

Understand, crankcase leakdown is not the same as a cylinder leakdown.  Cylinder leakdown won't work because you have to get the piston down below the intake ports for the air to get into the crankcase.  The problem there is the exhaust port opens first so all the air you try putting in, is going straight out the exhaust.

You are correct on that, but I’ll do my homework and see what I can find.  Sometimes all you need is to be pointed in the right direction:)

 

have a good one and thanks for all the help!

 

kevin

Keith you are way 2 good, a cherished resource for OMC engines. 

I truely appreciate your detailed replies and hope the BR members realize how special you are. This from a old Merc guy.

Tom

13 minutes ago, WRB said:

Keith you are way 2 good, a cherished resource for OMC engines. 

I truely appreciate your detailed replies and hope the BR members realize how special you are. This from a old Merc guy.

Tom

Tom,

He's a life saver for sure!  Now when it comes to IT, I've been doing that for 30 years, but trying to figure something out which you have never done, well guys like him are a life saver for sure.  Take what they give you for advice and try to learn from it   I've googled and googled, watched youtube videos, researched, but then I said it was time I post on BR to see if Keith or someone else could chime in for me

 

Kevin

One thought, look for the pulse valve for the fuel pump and see which cylinder it's coming off of.  If you are lucky it might be coming off the bottom cylinder.  To find it, look at the fuel pump, if your motor is not extremely old, there should be a hose going from the fuel pump to a fitting in the block, that fitting is the pulse valve.  The crankcase is divided into three sections, if that valve is in the lower section you are home free.  Let me know and I can tell you what to do from there.  If it's an older motor, the fuel pump will be sitting on the hole for the pulse.  Then it's a matter off where the pump is located.

One thing about that gas, that stuff is junk.  The problem is the station own/attendant is not doing their job. Gas tanks in the ground collect condensation, and it settles to the bottom of the tank.  At least once a week they are supposed to put a paste on the bottom of their measuring stick that changes color when it comes in contact with water.  When the water gets to a certain level in the tank, they are supposed to have it pump out.  That's where you are iin a catch 22, ethanol free gas doesn't hold the water so it accumulates much faster in the tank and is pumped out as water to the customer when the level gets to the fuel pickup.  Ethanol gas will absorb the water and passes on to the customer where, when left sitting can separate out and settle into the customers tank.

4 hours ago, Way2slow said:

One thought, look for the pulse valve for the fuel pump and see which cylinder it's coming off of.  If you are lucky it might be coming off the bottom cylinder.  To find it, look at the fuel pump, if your motor is not extremely old, there should be a hose going from the fuel pump to a fitting in the block, that fitting is the pulse valve.  The crankcase is divided into three sections, if that valve is in the lower section you are home free.  Let me know and I can tell you what to do from there.  If it's an older motor, the fuel pump will be sitting on the hole for the pulse.  Then it's a matter off where the pump is located.

I believe I know where you are talking about, but I will check when I get back home this evening and make sure.  I’ll let you know this evening and thanks again!

 

kevin

4 hours ago, Way2slow said:

One thing about that gas, that stuff is junk.  The problem is the station own/attendant is not doing their job. Gas tanks in the ground collect condensation, and it settles to the bottom of the tank.  At least once a week they are supposed to put a paste on the bottom of their measuring stick that changes color when it comes in contact with water.  When the water gets to a certain level in the tank, they are supposed to have it pump out.  That's where you are iin a catch 22, ethanol free gas doesn't hold the water so it accumulates much faster in the tank and is pumped out as water to the customer when the level gets to the fuel pickup.  Ethanol gas will absorb the water and passes on to the customer where, when left sitting can separate out and settle into the customers tank.

Did not realize that, but it really is good to know now   I was shocked to see the gas.  Some from the gas tank actually looked like diluted coffee at one point.

If that's the way it came out of the pump, sounds like it's a small, low volume station and the tank has a lot of rust in it.  This can be especially bad if they had a recent fuel delivery.  When the tanker dumps the new gas in, it stirs up all that crud they haven't pump out.  It can take a couple of days for the rust and crud to settle back to the bottom. 

That's why I try to only buy gas at high volume stations, they have larger tanks and a fairly high turn-over so you are not as likely to get that crappy gas. 

Also, do a little research on Top Tier Gas and then only buy that.  However, you were good on that part, I'm pretty sure Shell is rated as Top Tier.  Most of the major brands like Shell, Amoco, BP, Texaco, Exxon, etc are Top tier, but think the brands like Marathon, Walmart, Raceway etc are, The bulk of discount gases are not even good to run in a lawn mower.  If people could see what that discount gas does to the inside of and engine, they probably wouldn't go near the stuff.

Just looked and fuel pump is on bottom and the hose is going to the bottom cylinder.  Not great typing on the phone here lol.

after priming it looks like some is coming from the celenoid also.

ty

 

kevin

You might want to consider a inline addition fuel filter with water separator. Doesn't help your carburator problem now it will later with clean fuel.

Both E10 & E15 gasoline attacks older fuel lines not designed for it.

Suggest using a large fuel funnel with disposable filters to catch debris from fuel storage tanks.

Tom

Sounds like your planets must be aligned nicely.  Do you have an air compressor or a source for compressed air?  The reason for all this is, if you can get to the pulse valve, you can take it out, put the bottom piston on top dead center and apply about 20psi of air into the crankcase where you took out the pulse valve. If everything was perfect it would hold that air, but never seen a perfect motor so you will get a little blow by in places.  What you are listing for is air coming out of the carburetor with the throttle butterfly open.  A very slight amount, that could just be old reeds ab, what you don't want to hear is a lot of air coming out.  Lots of air means the intake will most likely have to come off to check reeds, gasket or recirculation valve.   

You need to fix any leaks you get when pumping the primer bulb.  The solenoid you a see is most likely the fuel enrichment.  You can by the gasket/parts to fix that.

1 hour ago, WRB said:

You might want to consider a inline addition fuel filter with water separator. Doesn't help your carburator problem now it will later with clean fuel.

Both E10 & E15 gasoline attacks older fuel lines not designed for it.

Suggest using a large fuel funnel with disposable filters to catch debris from fuel storage tanks.

Tom

That sounds like a plan Tom!  Ty for the preventive maintenance

1 hour ago, Way2slow said:

Sounds like your planets must be aligned nicely.  Do you have an air compressor or a source for compressed air?  The reason for all this is, if you can get to the pulse valve, you can take it out, put the bottom piston on top dead center and apply about 20psi of air into the crankcase where you took out the pulse valve. If everything was perfect it would hold that air, but never seen a perfect motor so you will get a little blow by in places.  What you are listing for is air coming out of the carburetor with the throttle butterfly open.  A very slight amount, that could just be old reeds ab, what you don't want to hear is a lot of air coming out.  Lots of air means the intake will most likely have to come off to check reeds, gasket or recirculation valve.   

You need to fix any leaks you get when pumping the primer bulb.  The solenoid you a see is most likely the fuel enrichment.  You can by the gasket/parts to fix that.

Yeah, I’ve got an air compressor. I’ll see if I can find the parts to replace what is wrong with the solenoid.  I’ll also try and do that test tomorrow too.  Ty!!

Understand, absolutely no more than 20 psi in the crankcase so make sure you have a good regulator on it.  The crankcase will not handle a lot of pressure.

14 hours ago, Way2slow said:

Understand, absolutely no more than 20 psi in the crankcase so make sure you have a good regulator on it.  The crankcase will not handle a lot of pressure.

Ty!  I’ll put my regulator I use for my hvlp gun when I spray finishes for my wood projects on it to be safe.  Hope to get to try it this evening ?  Also have a main one coming from my compressor as well to control overall psi.

ty!

If there is any question about the pressure, error toward the low end, 10-15 psi is fine if you have good volume.

1 hour ago, Way2slow said:

If there is any question about the pressure, error toward the low end, 10-15 psi is fine if you have good volume.

Ok, will do .  Ty!

Did not get a chance to do the test tonight, hopefully I can find time tomorrow evening.

 

Kevin

Did not get enough time to do what I really wanted to, but I took off the solenoid, all carbs, vro oil pump and examined all hoses.  What I found was from the hose on the solenoid there was a zip tie inside the hose!!!!!  I have no clue how this could have got in there and no telling how long it's been there.

 

I bought a rebuild kit for the solenoid tonight as it looked like the o-ring and gasket could be replaced. I also noticed one of the hoses from the vro pump was loose and did not have anything to clamp on it.  It was one near the bottom.  Gonna try to do those test's you suggested I do next tomorrow or the next.  Gotta travel out of state tomorrow

 

Ty!