PDA

View Full Version : Ok I am stumped....


TLR67
07-13-2011, 11:37 PM
Some of you may have seen my Vapor lock thread... Well it all started when I was coming back to the ramp friday pm and there was a slight hesitation at WOT... I figured it was water in the gas.. A little skeptickal since I drain my tank every year. I replaced the filters in the seperator and fuel pump too.. checked the gas and all was well.. Go to crank it and nothing... well she was turning over but didnt want to start.. I thought it was then the fuel pump but thanks to SKIDIM they told me how to check that and the pump was fine... I traced that down after putting in 8 new plugsect , setting the gap.. putting in the new coil ect... It turned out to be my Siphon Valve on my tank......She is running now but has a big hesitation at low speed like she's on 7 cylinders... I take her out and give gas and she runs great... Could this new Coil not be good? Couldm it be the choke? While running I saw gas going in all 4 bowlsds of the carb... Carb was rebuilt some time ago but I am thinking this Ethonal crap screwed up my 4160... Thoughts? Whats a easy way to check all plug wires? I know I dont have them crossed and checked all 8.. All seem snug and good... I will try my old Coil tomorrow....BTW, I dont have a timing gun or a spark plug tester.. I lifted them off the dist cap and heard clicking on them...Any help would be great.. Thanks in Advance....

TLR67
07-14-2011, 11:53 AM
Bump.... Any idea's? Or is everyone else stumped as well.....

TxsRiverRat
07-14-2011, 12:01 PM
Looks like you're checking the right things...

There's a vacuum hose that goes from the engine to the cap on the valve cover on the starboard side - check to see its connected and the cap is tight.

I ran my boat and that was accidentally disconnected a few weeks ago and i could not figure out why my boat was running like 'carp'

oldairboater
07-14-2011, 12:04 PM
Accelerator pump working? Can you see gas actually being pumped into the throats when you shove the accelerator down? Not flowing into the throats but actually pumped into the throats? You can test that visually. Don't start the boat. Just shove the accelerator down with you looking in the carb. One pump--one look. You may have to disconnect the linkage so you can work it while watching. Don't do this too much. Raw gas is not good for your engine. It will flood it. Coils usually break down and fire gets intermittent or nonexistent when they get hot.

JimN
07-14-2011, 12:06 PM
Some of you may have seen my Vapor lock thread... Well it all started when I was coming back to the ramp friday pm and there was a slight hesitation at WOT... I figured it was water in the gas.. A little skeptickal since I drain my tank every year. I replaced the filters in the seperator and fuel pump too.. checked the gas and all was well.. Go to crank it and nothing... well she was turning over but didnt want to start.. I thought it was then the fuel pump but thanks to SKIDIM they told me how to check that and the pump was fine... I traced that down after putting in 8 new plugsect , setting the gap.. putting in the new coil ect... It turned out to be my Siphon Valve on my tank......She is running now but has a big hesitation at low speed like she's on 7 cylinders... I take her out and give gas and she runs great... Could this new Coil not be good? Couldm it be the choke? While running I saw gas going in all 4 bowlsds of the carb... Carb was rebuilt some time ago but I am thinking this Ethonal crap screwed up my 4160... Thoughts? Whats a easy way to check all plug wires? I know I dont have them crossed and checked all 8.. All seem snug and good... I will try my old Coil tomorrow....BTW, I dont have a timing gun or a spark plug tester.. I lifted them off the dist cap and heard clicking on them...Any help would be great.. Thanks in Advance....

Check the plugs. If you pull a plug wire, you should notice a change in the idle quality, except on the one that isn't firing well/at all. If it doesn't change the idle quality, check the compression. The anti-siphon valve shouldn't affect WOT- that's why a carb has a bowl to have someplace to store fuel when demand is high. It also won't affect idle quality.

Get a timing light with the dial for setting advance. They're not that expensive. I got mine at Sears.

oldairboater
07-14-2011, 12:11 PM
I was going to mention dwell and timing but figured we would start with the accelerator pump first. I hate pulling plug wires as that always gets me lighted up and I have been told it is too dangerous with the new ignitions---too much voltage.

TxsRiverRat
07-14-2011, 12:24 PM
Just dont hold the wire while u turn the motor :D:D:D:D

TLR67
07-14-2011, 12:25 PM
I was going to mention dwell and timing but figured we would start with the accelerator pump first. I hate pulling plug wires as that always gets me lighted up and I have been told it is too dangerous with the new ignitions---too much voltage.

I have electronic ignition and no points.... I will check the Accelerator Pump... I have a new rebuild kit in a box but dont have the time to rebuild it before tomorrow.... Thanks Guys...