fuel problems in my scarab
10-03-2011, 11:22 PM
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fuel problems in my scarab
Any explanations appreciated. I'm a newbie.
Ok, i'll break this into two parts cause i can get windy. The first part basic problems, second part longer with more details for those of you who dare.
Boat=84 30ft scarab new 350's
I bent some push rods and come to find out it was a tar like substance coating the valve stems. Cleaned and put back together and purrs like a kitten again. Another problem is that I adjusted the floats in the carbs and there seems to be a disolved aluminum in it(for lack of better words). I rebuilt them a little while back and found the same thing and dismissed it being that i had no idea of their history and they ran great after words. Nothing in any of the filters. Carb screens are clean. Tank from best i can tell is clean. Two problems-1 tar in engine-source?2 carbs are melting-what the hell.
Ok for the more detailed version. I bought this boat with no drives motors or trailer. Other wise a beautiful boat. I chopped a heavy built 22ft trailer in half and add 10ft, new runners, axles, wheels/tires, fenders and paint. After the trailer i built me some yard arms for picking these boats up. My buddy also has a scarab. Then i built an A frame that is 20ft wide and about 16ft tall and collapses into a trailer so that i can pull it with my truck.(have to see it) The A frame i had wasn't tall enough to pull and put motors in these boats setting on trailers. As for the boat i robbed all my parts from a rotten 26ft cabin cruiser that had two brand new crate 350s in it and alpha ones. (I know I know alpha ones suck but its what i had and could afford) And i have two extra alphas and they are easy to swap if blow one up. But with just 350s in front of them they are doing fine. I run in the low 50s and the add i saw for my boat original said it ran 54 with 454s so I figure im doing ok. One day ill get me some bravos and big blocks though. I'm young. So the first lake trial went well. It was just this past labor day. Only problem was lost ignition on one engine and found a loose wire in the dash. The next weekend both motors were hard to start and then one started to miss and was followed by some valve noise. Once home i pulled the valve covers and found a rocker off its push rod and another bent push rod. My props are only 17pitch and so i assumed that i might have over revd. So i did the one more lake weekend hopeful thing to do and put new pushrods in hoping she would be ok then i would tear it down this winter. When I adjusting the valves i noticed the intake valves were slow to close. So assuming i had a bent valves i pulled the heads and found the tar like junk. Maybe bad gas. Break cleaner ate the stuff like it was nothing and valves slid right back in and now she runs great other than the carb issue. Now the other motor is making valve noise. Tried b12 in the fuel filter and MM oil in the pan. Didn't seem to help so i guess i need to tear her down as well. But i don't know where this stuff came from. Before i put the motors in i sucked almost 25 gallons of gas out of the tank and used it in my lawn mower with no problem. Rebuilt the carbs and they had no tar just the aluminum paste. The carb screens are clean, new filters, new fuel line. The guy i got the boat with the new motors was kind of an ass so maybe someone poured something in the motors. What would dissolve the carbs though? Not realizing what was happening i ran the motors three different weekends and the build up in the carbs doesn't seem to affect them. Was running great until the valves started to stick. I should state also that the carbs are the original mercarbs, 2gc i think, that came on the 88 model cabin cruiser. Old carbs new motors. I'm going to put four barrels on this winter so i don't really care about the carbs but would like to know what caused this. Kinda stumped on this one. I've built several motors, put a few jet boats together, couple camaros, 4x4s and tranys and rearends so i'm not completely helpless but i've never seen bad gas pull the studs out of a head. Oh yeah, two of the valves had started to pull the studs out of the head. Now thats stuck. I know i'm forgetting things but this has gone long enough so thanks for you time especially if you read this far lol.
Ok, i'll break this into two parts cause i can get windy. The first part basic problems, second part longer with more details for those of you who dare.
Boat=84 30ft scarab new 350's
I bent some push rods and come to find out it was a tar like substance coating the valve stems. Cleaned and put back together and purrs like a kitten again. Another problem is that I adjusted the floats in the carbs and there seems to be a disolved aluminum in it(for lack of better words). I rebuilt them a little while back and found the same thing and dismissed it being that i had no idea of their history and they ran great after words. Nothing in any of the filters. Carb screens are clean. Tank from best i can tell is clean. Two problems-1 tar in engine-source?2 carbs are melting-what the hell.
Ok for the more detailed version. I bought this boat with no drives motors or trailer. Other wise a beautiful boat. I chopped a heavy built 22ft trailer in half and add 10ft, new runners, axles, wheels/tires, fenders and paint. After the trailer i built me some yard arms for picking these boats up. My buddy also has a scarab. Then i built an A frame that is 20ft wide and about 16ft tall and collapses into a trailer so that i can pull it with my truck.(have to see it) The A frame i had wasn't tall enough to pull and put motors in these boats setting on trailers. As for the boat i robbed all my parts from a rotten 26ft cabin cruiser that had two brand new crate 350s in it and alpha ones. (I know I know alpha ones suck but its what i had and could afford) And i have two extra alphas and they are easy to swap if blow one up. But with just 350s in front of them they are doing fine. I run in the low 50s and the add i saw for my boat original said it ran 54 with 454s so I figure im doing ok. One day ill get me some bravos and big blocks though. I'm young. So the first lake trial went well. It was just this past labor day. Only problem was lost ignition on one engine and found a loose wire in the dash. The next weekend both motors were hard to start and then one started to miss and was followed by some valve noise. Once home i pulled the valve covers and found a rocker off its push rod and another bent push rod. My props are only 17pitch and so i assumed that i might have over revd. So i did the one more lake weekend hopeful thing to do and put new pushrods in hoping she would be ok then i would tear it down this winter. When I adjusting the valves i noticed the intake valves were slow to close. So assuming i had a bent valves i pulled the heads and found the tar like junk. Maybe bad gas. Break cleaner ate the stuff like it was nothing and valves slid right back in and now she runs great other than the carb issue. Now the other motor is making valve noise. Tried b12 in the fuel filter and MM oil in the pan. Didn't seem to help so i guess i need to tear her down as well. But i don't know where this stuff came from. Before i put the motors in i sucked almost 25 gallons of gas out of the tank and used it in my lawn mower with no problem. Rebuilt the carbs and they had no tar just the aluminum paste. The carb screens are clean, new filters, new fuel line. The guy i got the boat with the new motors was kind of an ass so maybe someone poured something in the motors. What would dissolve the carbs though? Not realizing what was happening i ran the motors three different weekends and the build up in the carbs doesn't seem to affect them. Was running great until the valves started to stick. I should state also that the carbs are the original mercarbs, 2gc i think, that came on the 88 model cabin cruiser. Old carbs new motors. I'm going to put four barrels on this winter so i don't really care about the carbs but would like to know what caused this. Kinda stumped on this one. I've built several motors, put a few jet boats together, couple camaros, 4x4s and tranys and rearends so i'm not completely helpless but i've never seen bad gas pull the studs out of a head. Oh yeah, two of the valves had started to pull the studs out of the head. Now thats stuck. I know i'm forgetting things but this has gone long enough so thanks for you time especially if you read this far lol.
10-04-2011, 07:32 AM
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That stuff in your carbs is from ethanol fuel being stored too long. Basically, phase seperation happening inside your carburetor. The water is corroding the aluminum (and other materials) inside your carb.
I've rebuilt many different carbs this spring. Some where rebuilt just last year...for same thing. So, it seams about 8 months is the time frame for this to happen. Could be happening earlier but too cold for me to unwrap the boats and pull the carb to see.
Does the stuff look like a white granular jelly ? If so, that is what I'm talking about.
This winter I plan to fill the seperators with a gas/marvel mystery oil (or 2 cycle pre-mix)/ stabil (or startron) mix therefore guaranteeing the carbs see the treated fuel. When the engines smoke from the oil added, I know the mix has gotten into the carburetors.
Of course, the stabil or startron will be added to gas tank for lst run of the season.
Read up on filling tank or emptying it for storage. Again, keyword to search for is ethanol phase sepration. Or E10 phase sepration.
I've rebuilt many different carbs this spring. Some where rebuilt just last year...for same thing. So, it seams about 8 months is the time frame for this to happen. Could be happening earlier but too cold for me to unwrap the boats and pull the carb to see.
Does the stuff look like a white granular jelly ? If so, that is what I'm talking about.
This winter I plan to fill the seperators with a gas/marvel mystery oil (or 2 cycle pre-mix)/ stabil (or startron) mix therefore guaranteeing the carbs see the treated fuel. When the engines smoke from the oil added, I know the mix has gotten into the carburetors.
Of course, the stabil or startron will be added to gas tank for lst run of the season.
Read up on filling tank or emptying it for storage. Again, keyword to search for is ethanol phase sepration. Or E10 phase sepration.
10-04-2011, 10:33 AM
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Wow. It sounds like you have your hands full.
As for the engines, they really sound like they have some issues going on. Tar, studs coming out of the heads, etc. If it were me, I'd pull both of them engines, and start from scratch with some fresh rebuilds. It sounds like there are some valvetrain issues going on for sure. Sooner than later somethings gonna break, and ruin the blocks, heads, or cranks, then its gonna start getting expensive.
As for the engines, they really sound like they have some issues going on. Tar, studs coming out of the heads, etc. If it were me, I'd pull both of them engines, and start from scratch with some fresh rebuilds. It sounds like there are some valvetrain issues going on for sure. Sooner than later somethings gonna break, and ruin the blocks, heads, or cranks, then its gonna start getting expensive.
10-05-2011, 12:13 AM
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thank you guys for your replies.
The stuff in the carbs is a soft gray metalic substance. like very finely ground aluminum. I drained the tank before i put the motors in and have gone through the carbs twice within the last two months. I wouldn't have thought it would be seperating this soon or fast. I don't disagree at all that something is eating at the carbs though. Maybe someone spiked my tank with a little something? Maybe drain it again even though i have around 100 gallons of fresh fuel in it?
And as for rebuilding the motors they are brand new. They ran great until i bogged down with this gummy substance. The motor i pulled apart and cleaned runs great again and no bad signs. Both motors run smooth and hold around 55psi oi pressurel. The motor i pulled apart looks as though the cylinders were just bored. After running the boat four times at the lake the oil looks as clean as it did when i put it in. So the problem seems to be isolated to the intake/fuel and valve train.
The stuff in the carbs is a soft gray metalic substance. like very finely ground aluminum. I drained the tank before i put the motors in and have gone through the carbs twice within the last two months. I wouldn't have thought it would be seperating this soon or fast. I don't disagree at all that something is eating at the carbs though. Maybe someone spiked my tank with a little something? Maybe drain it again even though i have around 100 gallons of fresh fuel in it?
And as for rebuilding the motors they are brand new. They ran great until i bogged down with this gummy substance. The motor i pulled apart and cleaned runs great again and no bad signs. Both motors run smooth and hold around 55psi oi pressurel. The motor i pulled apart looks as though the cylinders were just bored. After running the boat four times at the lake the oil looks as clean as it did when i put it in. So the problem seems to be isolated to the intake/fuel and valve train.
10-05-2011, 12:43 AM
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Anything your finding in your carbs should not be related to the valvetrain problems. As for a aluminum metallic substance in your carbs, that's odd. I can see if your tanks were corroding, but I would think the canister fuel filters would catch that and not allow it to get to the carbs.
When you say the aluminum substance is in there, I assume your talking about inside the fuel bowl? Or do you mean inside the throat of the carb?
When you say the aluminum substance is in there, I assume your talking about inside the fuel bowl? Or do you mean inside the throat of the carb?
10-05-2011, 01:07 AM
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I don't disagree but?
Thanks guys.
Mild Thunder
Yea sorry i'm not doing very well at being clear. Yea the stuff in the carbs is in the bowls. And i've changed the filters twice just in case they were bypassing. But even the old gas that I sucked out of the tank before i put the motors in was pretty clean and was sucked out completely unfiltered.
Mike Tkach
The springs are dual and strong but i would agree with what you said if i had just read what i wrote. This gum was some stout stuff. It was a task pushing the valves out once the springs were off, just the intake valves though. the first one i pushed out i considered pushing back in and cutting the top of the stem off because i assumed it was bent just bad enought not to want to come out but not enough for me to be able to see with a straight edge. Once out though i found there was no bend and the gum cleaned right off with some break cleaner. Valve slid right back in. Exhaust valves were just fine, no gum at all. Had to of come through the intake.
Mild Thunder
Yea sorry i'm not doing very well at being clear. Yea the stuff in the carbs is in the bowls. And i've changed the filters twice just in case they were bypassing. But even the old gas that I sucked out of the tank before i put the motors in was pretty clean and was sucked out completely unfiltered.
Mike Tkach
The springs are dual and strong but i would agree with what you said if i had just read what i wrote. This gum was some stout stuff. It was a task pushing the valves out once the springs were off, just the intake valves though. the first one i pushed out i considered pushing back in and cutting the top of the stem off because i assumed it was bent just bad enought not to want to come out but not enough for me to be able to see with a straight edge. Once out though i found there was no bend and the gum cleaned right off with some break cleaner. Valve slid right back in. Exhaust valves were just fine, no gum at all. Had to of come through the intake.
10-05-2011, 01:11 AM
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fixx
this pertains to cars,when the old man catches his girl friend cheeting on him he gets pi$$ed and poars a pound of sugar in her gas tank, well at leaste thats what this guy did to one of my female customers and the brown tar stuff was sitting in the bottom of the intake under the carb and was on the stems of the intake and exhaust valves..
try poaring seafoam down the carbs, read the directions and fair warning when doing this it will asmoke out the neighbor hood..
another thing it could be is if the guy that winterised the boat used a ton of fogging oil,after years of sitting it turns into grease..
try poaring seafoam down the carbs, read the directions and fair warning when doing this it will asmoke out the neighbor hood..
another thing it could be is if the guy that winterised the boat used a ton of fogging oil,after years of sitting it turns into grease..
10-05-2011, 01:24 AM
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Hmm, that could fit my situation. I get along with my neighbors but the guy i got the motors from, well... I wouldn't have got along with him. The entire time i was there all he talked about was all the women he Fxxx and wanted to show me pictures and on and on then his pissed wife showed up. Couldn't wait to get out of there. I tried a little b12 but no sea foam. I will do that. Im going to do something i've wanted to try for a while. I'm going to make an adapter to pressurerise the cylinders through the spark plug whole and pull the spring and seals and see if i can get something to loosen up the build up on the stems in the motor i haven't tor down. And then i will defenitely try the sea foam. Is that like the pouring tranny fluid down the carb and don't dare let it die kinda thing?
10-05-2011, 02:05 AM
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You can always get a leakdown tester kit, which will allow you to pressurize the cylinders, plus do a leakdown test while your in there. You can try some seafoam mixed in with the oil. Run it like it says, then do a oil change.
This spring I some lifter noise in my old 454 powered dually, after it sat in storage all winter. I added a pint of seafoam to the engine oil, took it for a ride. Came back, drained the oil, and filled with rotella diesel oil. Ran again for a few hundred miles, and did one last oil change. It's a older original engine with 130k miles. It was used to haul 5th wheel trailers, and when it wasn't towing, it sat for long periods of time. I know diesel oils are high detergent, so my theory was to run it hoping it would degunk the engine. Lifters are quiet now, towed the boat all summer with no problems. Whether it was what I did, or just a fluke, its running good. Granted its gonna probably need rings soon, as I get a decent amount of blowby out the valve cover with the filler cap off at idle.
Mike tkach and mrfixxall, I have your parts requested on standby for you guys. I'll try to get with ya guys next week sometime, ill be out of town this weekend.thx, Joe
This spring I some lifter noise in my old 454 powered dually, after it sat in storage all winter. I added a pint of seafoam to the engine oil, took it for a ride. Came back, drained the oil, and filled with rotella diesel oil. Ran again for a few hundred miles, and did one last oil change. It's a older original engine with 130k miles. It was used to haul 5th wheel trailers, and when it wasn't towing, it sat for long periods of time. I know diesel oils are high detergent, so my theory was to run it hoping it would degunk the engine. Lifters are quiet now, towed the boat all summer with no problems. Whether it was what I did, or just a fluke, its running good. Granted its gonna probably need rings soon, as I get a decent amount of blowby out the valve cover with the filler cap off at idle.
Mike tkach and mrfixxall, I have your parts requested on standby for you guys. I'll try to get with ya guys next week sometime, ill be out of town this weekend.thx, Joe
