130hp mercruiser skips bad after running for 30 min.

[Rickharrissr]

I have a 1987 searay with 130hp Mercruiser and after 40 minutes it start to run really bad, skipping, Changed distributor cap, plug wires,condenser,coil,cleaned carb. roder. and the problem is still there. put in dry gas, a water seperator.and still does it. Found a bare wire from alt touching alt. bracket. tape that and still does it. Took out valve where the gas line hooks to the gas tank cleaned all gas filters even the one going into carb. still does the same thing, after it gets hot, runs terrible, If I let it sit and cool off for an hour it will run good for a little while.<br />Anyway if you have the part I need to fix this very irritating issue, I'll buy it. {lol}<br /><br />Thank you very much for any impute.<br />Rick R. Harris, Sr.<br /><br />Richar41@aol.com

 

[trog100]

Re: 130hp mercruiser skips bad after running for 30 min.

okay how hot is hot.. is the engine running too hot and is it getting enough airflow to the engine compartment..<br /><br />forty minutes is longer than it should take for an engine to simply get to normal operating temperatures.. once it gets there it shouldnt get any hotter..<br /><br />is the gas tank venting properly that fits in with problems after forty minutes or so running..<br /><br />trog100

 

[Don S]

Re: 130hp mercruiser skips bad after running for 30 min.

Might be just a plugged fuel tank vent. Once you run it awhile and it starts creating a vacuum in the tank it leans the fuel mixture till it won't run. After it sits for awhile the plug in the vent allows enought air back into the tank to allow you another 30 minutes.<br />Next time it does that, just remove the fill cap and see if it immediatly picks back up.<br />Mud Dauber wasps are noted for plugging up vents.

 

[DHPMARINE]

Re: 130hp mercruiser skips bad after running for 30 min.

I realize it could be most anything,but I would spray carb cleaner along the mating surface of the cylinder head and intake/exhaust manifold,thinking the gasket could be leaking.<br /><br />DHP

 

[neilmw]

Re: 130hp mercruiser skips bad after running for 30 min.

Ooh ooh another old sea ray owner......or should that be another owner of an old sea ray <br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=009868;p=1#000008 <br /><br />Always good to nose at someone elses

 

[papdetomaso]

Re: 130hp mercruiser skips bad after running for 30 min.

cleaned all gas filters even the one going into carb <br />Rick, Did you clean or replace the gas filters,especially the one going into the carb?

 

[pine island fred]

Re: 130hp mercruiser skips bad after running for 30 min.

might have a finger filter in the tank pick up tube. copper like screen, remove tube and push out from the bottom. regards fred

 

[Rickharrissr]

Re: 130hp mercruiser skips bad after running for 30 min.

Originally posted by papdetomaso:<br /> cleaned all gas filters even the one going into carb <br />Rick, Did you clean or replace the gas filters,especially the one going into the carb?

 

[Rickharrissr]

Re: 130hp mercruiser skips bad after running for 30 min.

Cadet,<br /><br />Yes, Cleaned all of the gas filters, including the one where the gas line foes into the carb. It was dirty but still did it after about 40 minutes.<br /><br />Rick

 

[Rickharrissr]

Re: 130hp mercruiser skips bad after running for 30 min.

Originally posted by pine island fred:<br /> might have a finger filter in the tank pick up tube. copper like screen, remove tube and push out from the bottom. regards fred

 

[Rickharrissr]

Re: 130hp mercruiser skips bad after running for 30 min.

Fred,<br /><br /> Right at the gas tank where the line comes out. That vave was checked, air went thru it but took out the valve anyway and that can not stop the flow of gas<br /><br />Thank you <br />Rick

 

[Rickharrissr]

Re: 130hp mercruiser skips bad after running for 30 min.

Originally posted by DHPMARINE:<br /> I realize it could be most anything,but I would spray carb cleaner along the mating surface of the cylinder head and intake/exhaust manifold,thinking the gasket could be leaking.<br /><br />DHP

 

[Rickharrissr]

Re: 130hp mercruiser skips bad after running for 30 min.

DHP.<br /><br /> WOuld a leaking gasket cause the boat to go from running great to terrible after 40 minutes of running?<br />Thank You <br />Rick

 

[Don S]

Re: 130hp mercruiser skips bad after running for 30 min.

Originally posted by Rickharrissr:<br /> DHP.<br /><br /> WOuld a leaking gasket cause the boat to go from running great to terrible after 40 minutes of running?<br />Thank You <br />Rick

No. Leaking gaskets will normally be noticed at idle speed first. At higher speeds, the exhaust pushes the water out faster than it can come in.<br />If you had bad valves you could suck water back into the engine, but it also wouldn't run very good at idle either.<br />Did you check your vent as I ask earlier. If it's plugged, they your fuel pump draws a vacuum and can't put fuel to the carb.<br />You may also find the timing advance is not working which will cause problems./<br />You mentioned you used dry gas and installed a water seperating fuel filter, have you checked the filter? IF it gets full of water it will then allow water to the carb, then you are right back where you started from.<br />If you do find a lot of water, you may have to drain the water from the tank. You will also need to get it out of the carb if that is the problem.