Tri-power malady.
Thread Starter
Drifting
Joined: Nov 2002
Posts: 1,691
Likes: 206
From: Loveland, CO
Tri-power malady.
Tried to start my '69 tri-power today to move it around the garage for winter. The starter turned about 1/2 revolution and hydraulic locked up. I looked down the carb bores and saw standing gasoline. Took out the spark plugs and two cylinders flowed gas. So I took off the carbs, dryed out the bottom of the manifold and blew out the cylinders with compressed air. Gas kept dribbling out of the disconnected fuel line and I determined that the full gas tank was higher than the line outlet. Jacked up the front of the car and the dribbling stopped. I'm not sure how gas could get through the stock mechanical fuel pump. Am letting the engine dry out overnight. I just changed the oil, but probably should do so again.
What could cause this situation? Sticking upen float bowls? I think the full tank contributed, but not sure. Any ideas?
Ralph.
What could cause this situation? Sticking upen float bowls? I think the full tank contributed, but not sure. Any ideas?
Ralph.
Le Mans Master
Joined: Nov 2001
Posts: 8,799
Likes: 1,942
From: LONG ISLAND
2025 C3 ('68-'73) of the Year Finalist - Unmodified
2024 C3 of the Year Finalist - Unmodified
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Gas Smell
I smell gas all the time everytime i turn the car off, stinks up entire garage & house............must i also have the same sticky float issue ?
ZIXXX PACKER
ZIXXX PACKER
Safety Car
Joined: Oct 1999
Posts: 4,101
Likes: 10
From: NorCal
Gaaaahhh!, you guys are scarin' me bad! Yes, fuel can siphon thru the pump, but it has to have somewhere to go. Only a stuck float/needle will do it and it can be any of the carbs. Once you've "dried out" the engine (and I'm assuming great ventilation every step of the way, AWAY from a ignition source -water heater, spark, etc..), fire it up and determine which carb it the culprit. You'll know because it'll flood over after a few seconds, or drip badly in the venturi after you shut ut off. This assumes you have the air cleaner off so you can see what's going on, and you have an extinguisher handy. A helper is a real good thing here. Once you know which one, you can try "rapping" the needle/seat assy,. but it's a crap shoot at best. DON'T beat it to death! Easiest (and a sure thing) is to buy a replacement needle/seat assembly from Holley. Don't buy the after-market ones with the brass nuts and O-rings, they're too tall and hit the air filter base. Buy only the original with the alloy slide nut and screw lock top.
Hans
Hans
Le Mans Master
Joined: Mar 2004
Posts: 7,493
Likes: 1,502
From: Little Rock AR
Originally Posted by rponfick
Tried to start my '69 tri-power today to move it around the garage for winter. The starter turned about 1/2 revolution and hydraulic locked up. I looked down the carb bores and saw standing gasoline. Took out the spark plugs and two cylinders flowed gas. So I took off the carbs, dryed out the bottom of the manifold and blew out the cylinders with compressed air. Gas kept dribbling out of the disconnected fuel line and I determined that the full gas tank was higher than the line outlet. Jacked up the front of the car and the dribbling stopped. I'm not sure how gas could get through the stock mechanical fuel pump. Am letting the engine dry out overnight. I just changed the oil, but probably should do so again.
What could cause this situation? Sticking upen float bowls? I think the full tank contributed, but not sure. Any ideas?
Ralph.
What could cause this situation? Sticking upen float bowls? I think the full tank contributed, but not sure. Any ideas?
Ralph.
-Mark.
Racer
Joined: Mar 2006
Posts: 473
Likes: 0
From: Mooreville Ms.
Originally Posted by rponfick
Tried to start my '69 tri-power today to move it around the garage for winter. The starter turned about 1/2 revolution and hydraulic locked up. I looked down the carb bores and saw standing gasoline. Took out the spark plugs and two cylinders flowed gas. So I took off the carbs, dryed out the bottom of the manifold and blew out the cylinders with compressed air. Gas kept dribbling out of the disconnected fuel line and I determined that the full gas tank was higher than the line outlet. Jacked up the front of the car and the dribbling stopped. I'm not sure how gas could get through the stock mechanical fuel pump. Am letting the engine dry out overnight. I just changed the oil, but probably should do so again.
What could cause this situation? Sticking upen float bowls? I think the full tank contributed, but not sure. Any ideas?
Ralph.
What could cause this situation? Sticking upen float bowls? I think the full tank contributed, but not sure. Any ideas?
Ralph.
Thread Starter
Drifting
Joined: Nov 2002
Posts: 1,691
Likes: 206
From: Loveland, CO
Stingr69, yes Lars is usually a great help. We live about 2 miles apart, but he is usually wandering the world tuning Quadrajets (with a beer in hand). He wouldn't work on the Edelbrock carb. I had on my '73. I think he feels a little better about Holleys.
Thanks guys for the comments. For the amount of gas in the manifold and the cylinders, there had to be some percolation from the full gas tank. I agree that a faulty float would be about the only way the gas could get into the engine.
You guys with only one carb. are missing out on a lot of fun. As someone has told me before "It must be the bling thing".
Thanks again. Ralph.
Thanks guys for the comments. For the amount of gas in the manifold and the cylinders, there had to be some percolation from the full gas tank. I agree that a faulty float would be about the only way the gas could get into the engine.
You guys with only one carb. are missing out on a lot of fun. As someone has told me before "It must be the bling thing".
Thanks again. Ralph.
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Thread Starter
Drifting
Joined: Nov 2002
Posts: 1,691
Likes: 206
From: Loveland, CO
Tommy, I was just thinking about that as I was going through my carbs.
If the gas leaks out of the bowls slowly, either through evaporation or the usual leaky Holley bowls, could gas continue to be brought into the bowls and possibly leak into the manifold? You are correct if the floats drop down and if the tank is full and the fuel level higher than the carb inlet, you could have a problem.
I'm thinking that keeping your tank fully filled is not the best idea.
Am I the only one to ever have this problem?
Ralph.
If the gas leaks out of the bowls slowly, either through evaporation or the usual leaky Holley bowls, could gas continue to be brought into the bowls and possibly leak into the manifold? You are correct if the floats drop down and if the tank is full and the fuel level higher than the carb inlet, you could have a problem.
I'm thinking that keeping your tank fully filled is not the best idea.
Am I the only one to ever have this problem?
Ralph.
Racer
Joined: Mar 2006
Posts: 473
Likes: 0
From: Mooreville Ms.
Originally Posted by rponfick
Tommy, I was just thinking about that as I was going through my carbs.
If the gas leaks out of the bowls slowly, either through evaporation or the usual leaky Holley bowls, could gas continue to be brought into the bowls and possibly leak into the manifold? You are correct if the floats drop down and if the tank is full and the fuel level higher than the carb inlet, you could have a problem.
I'm thinking that keeping your tank fully filled is not the best idea.
Am I the only one to ever have this problem?
Ralph.
If the gas leaks out of the bowls slowly, either through evaporation or the usual leaky Holley bowls, could gas continue to be brought into the bowls and possibly leak into the manifold? You are correct if the floats drop down and if the tank is full and the fuel level higher than the carb inlet, you could have a problem.
I'm thinking that keeping your tank fully filled is not the best idea.
Am I the only one to ever have this problem?
Ralph.
Thread Starter
Drifting
Joined: Nov 2002
Posts: 1,691
Likes: 206
From: Loveland, CO
Carl, not sure yet if anything damaged.
Tried to start it this morning, but still would not turn over. Took all the plugs out again and found another cylinder full of gas. I thought I had them all the first time, but this one must have escaped me. Cranked engine over with all plugs removed to clear out any remaining gas. Shot air in the cylinders again. Shot a little oil in each cylinder to give it some lubrication. Am awaiting my wife to return to stand fire extinguisher duty and help out.
Ralph.
Tried to start it this morning, but still would not turn over. Took all the plugs out again and found another cylinder full of gas. I thought I had them all the first time, but this one must have escaped me. Cranked engine over with all plugs removed to clear out any remaining gas. Shot air in the cylinders again. Shot a little oil in each cylinder to give it some lubrication. Am awaiting my wife to return to stand fire extinguisher duty and help out.
Ralph.
Thread Starter
Drifting
Joined: Nov 2002
Posts: 1,691
Likes: 206
From: Loveland, CO
Started the tri-power up this afternoon and it runs like usual. Looks like I may have dodged the bullet.
Lessons learned: Don't store nose slightly downhill with a full tank of gas. Maybe, don't store with a full tank of gas period.
Ralph.
Lessons learned: Don't store nose slightly downhill with a full tank of gas. Maybe, don't store with a full tank of gas period.
Ralph.