Here's an example of an anti-siphon valve.
http://www.discountmarinesupplies.com/F ... VALVE.html
They usually are screwed into the fitting on the top of the tank.....The fuel line to the filter usually connects to the hose barb side.
Cheers,
| www.iFourWinns.com https://www.smwebhead.com/phpBB3/ |
|
| 5.8L OMC Cobra https://www.smwebhead.com/phpBB3/viewtopic.php?f=11&t=2204 |
Page 1 of 1 |
| Author: | holysmokes [ Thu Jul 17, 2008 6:11 am ] |
| Post subject: | 5.8L OMC Cobra |
Went to run the boat for the first time and it would start,run, and then after about 3 sec. die. I found out that the gas was OLD (2 Years) so I drained every bit out. Also found that the fuel filter was the orginional....1992. I changed the filter. I put fresh gas with the carb cleaner and its trying to run but dies again. This is a 1992 sundowner boat with 5.8L motor. Any help or ideas you can send this way? BTW I can put gas in the bowls of the carb and it will run for a little longer.Fuel pump is not an electric one?Thanks. |
|
| Author: | Aussie_Horizon_190 [ Thu Jul 17, 2008 6:51 am ] |
| Post subject: | Re: 5.8L OMC Cobra |
Sounds to me like the fuel pump may be bad. These normally have a diaphragm inside them and the old gas may have made it go brittle. |
|
| Author: | millhaven_nice_guy [ Fri Jul 18, 2008 6:46 am ] |
| Post subject: | Re: 5.8L OMC Cobra |
I have a neighbour who got an older 1978 Peterborough boat and we have been working on it alot lately. He is having a similar problem. We have already tried what you described and it helped but still loses power at the top end from lack of fuel. We will be replacing the fuel pump and he is getting a rebuilt carb for it too. We are also going to check the timing and do a tuneup on the motor (cap, rotor, wires and plugs) If all this doesn't fix it then I am at the end of the rope! Just keep plugging away and eventually you'll get her running like she should. Unfortunately, it will cost you some money nut you will know that it will be reliable. |
|
| Author: | ht32bsx115 [ Fri Jul 18, 2008 1:14 pm ] |
| Post subject: | Re: 5.8L OMC Cobra |
Howdy, It's very possible that you also have a fairly "gummed up" carb and fuel pump if that gas sat in it for 2 years. In addition you may have a stuck/sticky anti-siphon valve at the tank or a partially clogged in-tank pickup/screen. You need to start at the tank and work your way to the carb. A boat that sat that long with "old gas" in it should probably have the fuel pump replaced. You may have to either rebuild or replace the carb. http://www.marinecarburetor.com/index.html Cheers, |
|
| Author: | holysmokes [ Fri Jul 18, 2008 3:42 pm ] |
| Post subject: | Re: 5.8L OMC Cobra |
Thanks for all of the replys. I have tried cleaning the carbs,and the anti syphon valve. The valve appeared to have a varnish like fluid comming out of it. (old old gas LOL) Bad thing is this isnt even MY boat. Im doing this for a family member that has fallen upon bad times. I can make the boat run if I put a little fuel in the carb. Its just the fuel getting to the carb that is lacking. I took the rubber line off the fuel filter housing and started motor. No fuel comming out of it. I guess this leads to the pump? If so, the pump is mechanical or electric. Im comfortable changing an electric pump, not so much a mechanical one. Thanks again. Smokes |
|
| Author: | BrentC5Z [ Fri Jul 18, 2008 4:10 pm ] |
| Post subject: | Re: 5.8L OMC Cobra |
Mechanical ones are a cinch. Don't be scared. |
|
| Author: | holysmokes [ Fri Jul 18, 2008 4:32 pm ] |
| Post subject: | Re: 5.8L OMC Cobra |
Does anyone have any info in the anti-syphon device on the 5.8L OMC. Pictures? What I took apart might not be the AS device. What I took apart was behind the fuel filter and had a little "dome" to it and had a single blue wire to the top of this dome. I shook it and could hear a slight rattle. I just talked to someone else and they said to look for a device comming out of the tank with a "ball bearing" to it. Again, thanks for all the input guys! |
|
| Author: | ht32bsx115 [ Fri Jul 18, 2008 9:02 pm ] |
| Post subject: | Re: 5.8L OMC Cobra |
Here's an example of an anti-siphon valve. http://www.discountmarinesupplies.com/F ... VALVE.html They usually are screwed into the fitting on the top of the tank.....The fuel line to the filter usually connects to the hose barb side. Cheers, |
|
| Author: | holysmokes [ Sat Jul 19, 2008 7:32 am ] |
| Post subject: | Re: 5.8L OMC Cobra |
OK yea, thats not what I took apart. My sister and brother in law want to trailer the boat about 650miles one way for them. In the past week, Ive put 4 new tires on the trailer ("oh the tires are only 2 years old....have a mfg date of 8 years ago) 4 sets of inner and outter bearings,grease seals,bearing buddys ect, and a new fuel fliter. After finding out the gas was 2 seasons old (1/4 tank) I decided to get the "ear muffs" on the motor and see if I would fire. Being frustrated is a deffinate understatement. To have this great info from you guys means alot. Thanks again. BTW Lord willing I get this thing running, is there anything that I should do or not do while getting fuel system back to "normal"? |
|
| Author: | holysmokes [ Sat Jul 19, 2008 8:15 am ] |
| Post subject: | Re: 5.8L OMC Cobra |
UPDATE! I pulled the floor over the tank. Found the valve. It wasnt stuck. I cleaned it for good measure. I did find fresh fuel between the valve and the filter housing. Is there a need to put fuel in the filter prior to installing it? |
|
| Author: | holysmokes [ Sat Jul 19, 2008 11:09 am ] |
| Post subject: | Re: 5.8L OMC Cobra |
How about that...Im no longer tadpole status! LOL Well, I pulled the fuel line off the carb. I now have fuel going TO it. found a huge hunk of varnish on the screen. After looking at carb closely, it has it all through it. Time to rebuild carb. 
|
|
| Author: | ht32bsx115 [ Sat Jul 19, 2008 2:45 pm ] |
| Post subject: | Re: 5.8L OMC Cobra |
It's not always the carb. I pulled my carb apart on the previous 460 King Cobra (only 20 years old) only to find out it was absolutely PRISTINE inside. All the gaskets were perfect......except I destroyed them taking it apart  I rebuilt it with a Sierra marine kit from NAPA Autoparts. Your other choice is to send it to Flying fish for either a rebuild or exchange. I think I would probably do that this time since they actually flow-test them before they send them out. You know what you have then. If you have a problem after that it's probably not the carb. Since you have the tank exposed, you might check the fuel pick-up screen inside the tank if you haven't already. holysmokes wrote: How about that...Im no longer tadpole status! LOL Well, I pulled the fuel line off the carb. I now have fuel going TO it. found a huge hunk of varnish on the screen. After looking at carb closely, it has it all through it. Time to rebuild carb.
|
|
| Author: | holysmokes [ Sun Jul 20, 2008 8:57 pm ] |
| Post subject: | Re: 5.8L OMC Cobra |
It looked varnished. I am however NO expert. Ive been getting quotes on new ones. Im not shelling out between $800 - $1200 on a new one.  The place I took it too just said " Holley is the biggest piece of poop, and we'll see what we can do".  If they say it cant be rebuilt I think I will take it somewhere that can AND flow test it. Anyone know a size or part # / specs on that particular carb?
|
|
| Author: | ht32bsx115 [ Mon Jul 21, 2008 11:18 am ] |
| Post subject: | Re: 5.8L OMC Cobra |
$800-1200 for a carb rebuild? What kind of place charges that much for a rebuild? I think Flying fish will turn that carb around for under $300 Eng, 5.8L, 1989-95, 4V Carb, H4, 4160 Model number R80383, (E8JL-9510-CA) Y41 Price: $248.00 Core charge: $88.00 |
|
| Author: | holysmokes [ Mon Jul 21, 2008 6:53 pm ] |
| Post subject: | Re: 5.8L OMC Cobra |
No, that was for a new one. I found out today that the one I have can be deep cleaned and will be just fine. He stated the orifaces were so plugged the compressor could not blow through them. He charged me $175 to do this. This is all new to me. Appliance repair is my gig. The info here has helped me out TREMENDOUSLY! Thanks a million! 
|
|
| Page 1 of 1 | All times are UTC - 6 hours [ DST ] |
| Powered by phpBB® Forum Software © phpBB Group http://www.phpbb.com/ |
|