Buddy Novak

Boat started and ran good for 1 hour. Stopped to swim for about 15 minutes then TRIED to start boat then would spudder and die, spudder and die. Gas gauge was on 3/4's full but called my buddy for gas just in case with no success. He towed me in and about 30 minutes later while being towed, I finally got it started. It was definintely missing and running rough and would barely idle. Took it off tow and made it back to trailer keeping it reved up. Got it on the trailer and brought it home. Now what?

I have been reading about VST, schrader valves, and vapor locking? Where would you start? I hate to take it in and spend the big bucks plus it never gets fixed right the first time and they charge you for things that are not needed. I am not sure if it has the VST or the fuel cooler setup but will get in the boat later this week and try to figure it out? I have been running fuel stabilzer and never have had a problem. Is the gas tank easily accessible? Where is the anti-syphon valve I have read about on here located? I have owned this boat from new and it only has 125 hours on it since 2000. What would be the easiest? The racor fuel filter? the fuel pumps / injectors? drain the gas tank? I am open for any ideas. Please advise if any ideas!! If it is a fuel problem would you change the plugs or not? Which type of plugs do you recommend. I have only changed fluids and filters on this boat never anything else. Any ideas would be greatly appreciated.

HiPerf2000

I would look into replacing the fuel/water separtor first. I change these every season along with the plugs and cap/rotor. You have a single motor, so plugs are not too difficult.

hp500efi

sounds like mine when it vapor locks. All I do is open the hatch for a while to let the heat out and runs just fine.

velo

seeing as you were running well to begin with it sounds like you have a fuel issue on your hands.. Im no expert but having just gone through this, I might suggest a few places to look , first hi-per is right on with the water fuel separator.. thats the definite quick,easy, cheap first step..
second place to look would be @ the injectors one clogged one is all its gonna take, and a good bottle of injector cleaner will likely take care of that... Third, well just hope its not your fuel pumps.. they get expensive good luck! MW

Buddy Novak

Thanks for the replies. On the injector cleaner would you take them out & clean or just add the cleaner to the fuel tank? Never have messed with the injectors. Thanks

BN

velo

time permitting then taking 'em out is certinly the best route to go...
(blow em out backwards with compressed air)
Quality injector cleaner might do the trick without the work, and certinly isnt going to hurt anything...
good luck

articfriends

Before you get too ambitious and do alot of un-neccesary work,take a look at the simple things. 1.-if your motor vapor locked (which the 2000 mpi system DOES not normally do),your boat would start up fine after it cooled down 2.You can change the fuel/water seperartor but unless you got a s--t load of water on your last fill up it wouldn't run fine then just not start (it would start losing top end). 3-check fuel pressure w/a gauge (when you turn key to run and your fuel pump kicks on for 5 seconds or whatever it does-is the noise of pump any different?) 4.IGNITION system-pull dist cap and look at pickup coil and wires in it-I ran stock merc dist in my 2000 502 and after 200 hours i pulled motor to put in new motor-when i touched p/u coil wires they crumbled/disintergrated,water seems to drip directly onto distributer on bajas from engine cover mine looked like it had saltwater get in it and mine has never seen the ocean. I have seen gm vehicles w/same distributer barely start/run because of bad p/u coil and they run fine one minute then won't start or barely run the next minute.5-injectors- highly doubtful-1 bad injector could pull down fuel pressure if it sticks open but you will literally have gas running out of that cylinder when you pull the plugs or at least one really wet plug,not hard to check,take good look at plugs before you rip injector rail/plenum etc apart 6.-Anti-siphon ball in pickup on tank-also doubtful,pulled mine out of my 2000 baja when i replumbed fuel system for 540,was spring loaded,can't really foul shut,can get stuck open (which would defeat it's purpose but not kill your motor) ALOT of work to get to(rear seat&base have to come out,gas tank cover has to come out)-easily checked without ripping boat apart-unhook supply line AFTER fuel pump and turn key on w/end of line in a suitable container but you will know from your fuel pressure test if there is a problem anyways. i hate standing on my head in my baja trying to work on it and i'm sure you do too so check the easy things first,good luck,post us with your results,i'm betting on your distributer,Smitty

Buddy Novak

The weather finally cleared and I got in the boat and changed the water/fuel separator filter. I was going to go ahead and remove my sea pump and check the rubber impeller but that is a real ***** standing on your head so I gave up on that after dropping two sockets in the bottom and trying to remove the hoses. I filled the new filter with 1/2 gas and 1/2 with fuel injector cleaner tightened her up and she fired right up on the water hose. I let her idle and got to operating temperature then did numerous start/stops and never bobbled.

When turning on the key, you can hear the electric fuel pump just fine. I do have the cool fuel versus the VST tank. I was worried about it because that's another stand on your head job on the other side of the engine.

How in the hell do these guys work on these motors at the shop? I assume they must pull the motors. I am an average nuts and bolt guy, but damn you have to be a contortionist to do any of this work. I am going to replace the plugs with the AC rapid fire #1's and call it good before I go to the water this weekend. Any tips on plug changing before I tackle it? I would really like to know how the shops perform this work? MUST HAVE BEEN THE FUEL FILTER. I have never had it changed in 5 years so I guess you could say I deserved it and got my moneys worth. Would you go ahead and change the cap and rotor also? I can't seem to ever have a parts guy in at the boat store for those parts due to the boat show here in Houston taking place this week.

Thanks for all the replies . I Really enjoy reading on this site.

Be safe.

Buddy

Buddy Novak

Finally got a chance to change the plugs to Rapid fire #1 and the old plugs did not look too bad after 5 years and 120 hours. Not too sore either from standing on my head.

I decided to take off the distributor cap and wow! The contacts were aluminum and the corrosion was unreal. The rotor was worn so I went down to the parts store and purchased a new cap/rotor and will be installing them this am. Maybe this was why it wouldn't stay running once it was hot?

I noticed the spray or discoloration on the bottom of the distributor cap? I assume that helps seal the cap? I bought some electrical sealing spray but not sure best way to apply it? Please advise.

Also the #1's are a tad longer than the original plugs. I assume that is why they burn better being deeper in the combustion chamber and leave the soot off the transom. I hope they do not hurt anything. Thanks again for all the tips. You guys have saved me tons of money for sure. Have a safe and nice weekend.

BN

articfriends

Buddy,thats why i told you to check your distributer,mine looked like it had been in saltwater when i took it out of boat after 3 yrs,good luck,Smitty