Bad Gas
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=2017
Printed Date: November-26-2024 at 7:25am
Topic: Bad Gas
Posted By: Guests
Subject: Bad Gas
Date Posted: July-06-2005 at 5:45pm
| I have a '90 SN that I have not started in 2 years. Ran great 2 summers ago. I failed to put fuel stabilizer in the tank back then. Now the engine turns over but won't start. I just syphoned all the gas out of the tank and put in new premium gas. Still won't start, but I did get a single backfire this morning, so I am encouraged (I think). There is probably old fuel left in the fuel lines and fuel filter. How long do you think it will take for the fresh gas to reach the carb? Any other suggestions (I'm a rookie)? THanks in advance! |
Replies:
Posted By: mackwrench
Date Posted: July-06-2005 at 5:59pm
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First thing is to unhook the gas line at the filter ( I think your is mounted on the left side stringer) and using a air hose or something blow all the old gas from the lines, change the spin-on filter as its full of yuk as well, unhook the line at the carb and get all old fuel you can from the pump back.You may need to rebuild the carb, sometimes when stored long periods with gas in carb all the gaskets will shrink causing a leak, and yuk grows in the bowls. Two years is a long time to let yuky gas sit in you carb! After you get it running add a pint of (Sea-Foam) you can get it at a auto parts place, to a tank of fuel and that may help clean the tank. ------------- NO LONGER A MEMBER |
Posted By: 79nautique
Date Posted: July-06-2005 at 7:00pm
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Rebuild the carb now, otherwise you are just going to have problems. With the gas setting it that long everything is gummed up and varnised over so the needle and seat, metering blocks, accel pump and everything else need to be replaced and/or cleaned in a tank of carb cleaner. A can of gumout isn't goint to get the job done. Also check the cap and rotor odds are they're rusted up and need replaced as well. Flush the fuel lines and replace the filters as suggested by mackwrench and have the carb rebuilt and you will save a lot of time and be back on the water trouble free. Also you need to replace the impeller and change the oil and filter as well. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: Guests
Date Posted: July-07-2005 at 1:03am
| Wow-My first time on this forum... you guys are great. Thanks for taking the time to respond! If I could push my luck a little farther with you, pertaining to rebuilding the Holly carb, I know I can get the rebuild kit at DIM, and if I am reasonably handy, do you think I could rebuild it myself? Once it is back together, is it easy to adjust the settings or would I need to take it into the shop? On an unrelated issue, when my battery died a couple of years ago, I replaced it with a deep cycle marine battery. I have read on a couple of posts this is not good, that I should just use a regular battery. Any thoughts? |
Posted By: Bob's2001
Date Posted: July-07-2005 at 3:09am
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I rebuilt my Holley just this spring with a kit from Summit Racing, cheaper than other places and it's the same kit. I am only reasonably handy in spurts. Take your time, take notes (pictures are great if you have a digital camera or go get them developed ). The kit has a exploded view of all the parts. You can do it, and if it don't work then call the mechanic. ------------- Bob Ed 83 2001 |
Posted By: skyhawkflyer
Date Posted: July-07-2005 at 10:15am
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Jim,
Do a carb search on this site. There have been some recent good posts about Holley rebuilts, power valves, float settings, idle adjustments etc. Also available at Holley.com is a rebuild book specifically for marine Holley's. I'm sure it has some good info in it.  ------------- |
Posted By: David F
Date Posted: July-07-2005 at 12:47pm
|
Jim:
If you attempt the rebuild yourself, make sure you note the position of the idle mixture screws and to a lesser extend the idle speed screw. Simply count turns to lightly seated and after rebuild adjust to same setting and you should be good to go. Does a '90 SN have ignition points? If so, sand them clean before doing anything else. After two years, they can rust over and cause a no spark condition...happen to me this year on my '77 after sitting the winter. You might try giving the engine a shot of starting fluid to see if it will fire. If not, look for no spark. If yes, get that old fuel out of the lines. Make sure it is not flooded with old fuel. See if it runs ok (after you get it to fire) before rebuilding the carb, you may get lucky. I also would try running two cans of BG 44K (fuel system cleaner) in one full tank. This stuff is amazing. |
Posted By: Guests
Date Posted: July-07-2005 at 4:38pm
| Thanks again, guys, for all the advice. I actually got it running this morning without rebuilding the carb. I think it just took a few days of trying to get the old fuel out of the lines. Runs great above 1,000 rpm, a little rough below that and tends to stall at idle. Should I just adjust the idle up to 1,000 rpm? I'll try the fuel cleaner you suggested, David. Thanks! |
Posted By: David F
Date Posted: July-07-2005 at 4:50pm
| The idle circuits are most suseptible to gum and varnish. See if the cleaner helps. By idling up, you are simply bypassing the idle circuits and opening the throttle plates...for the cleaner to work, you must get the fuel to flow through the idle circuits. Briefly closing the choke on a warm engine until it almost stalls (with throttle plates fully closed) forces a higher vacuum through the idle circuit which can help clear them out. |
Posted By: Siveck
Date Posted: July-07-2005 at 4:55pm
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About the deep cycle battery:
I do not reccomend that battery for our boats. A deep cycle battery is meant to run a trolling motor for a period of time. They also work for cranking a little outboard motor. However, we have bigger American V8's that need a little more battery power for cranking. I use an automotive battery that fits in the battery well. I always had trouble with cranking when I had the deep cycle battery. I haven't had any trouble with the automotive style. ------------- 1975 Ski Nautique "Small Letter Boat" |