View Full Version : 89 PS 190 Carb. timing, alternator question

08-26-2007, 11:07 PM
First time poster, long time reader. Have learned a ton in the last year since buying our first MC.

Have a 89 Prostar 190. 550 hours, 351 indmar and Powerslot.

Has the 4160 carb and boat runs real rich from time to time. Was just rebuilt over winter and ran fine up till last weekend. I pulled the flame arrestor, and the right (drivers side) front venturi is dripping gas down onto the butterfly. About a drip a second at idle. Its loading up and black "soot" soot in the water, and all over the back of the boat under the platform. It is also starting hard. I tapped the front bowl last night and it ran great for the next few hours, then later today back doing the same again.

2nd question is about timing. Has electronic ignition... assume it was converted before I got it and was orig. points? What should my timing be set at. If I remember reading correctly, it should be advanced a few degrees from what the manual says?

3rd boat seems to not want to start by the end of the day like battery is about dead. Just put new Red top Optima in it about a month ago. Wondering if altenator is on the way out? I have not had a chance to pull it to have it tested. Best place to buy a new one? Or any of you got a good used one laying around?

Thanks in advance for all your help.

Granbury Texas
1989 PS 190

88 PS190
08-26-2007, 11:32 PM
carb, when you have it rebuilt was it set on an angle like it sits in the boat or flat like it was going in a carb, that could say change the float level set up.

Don't have my manual with the timing.

For the charging system get a multimeter and check the battery before you start it, then afterwards, before should be around 12 volts, while running it should be above 14 volts.

I would not pay for a new alternator even if that wasn't the figure, I know you don't want to rebuild it yourself (though you could its easy) atleast up here the alternator can be rebuilt for less than 60 bucks.

I would be tempted to check he starter, I mean for sure check your charging system, but if the starter is going bad sometimes it won't work properly when hot (like after running)

08-27-2007, 12:56 AM
If the engine was running fine and then started running rich, I would suspect that some debris is lodged in the needle valve, thereby causing the carburetor to flood. You'll need to clear the debris from the needle valve and then replace the fuel filters.

The engine timing should be set at 8 degrees before top dead center at idle.

As regards the battery appearing to lose its charge, check the alternator belt to make sure it is not slipping. Then check the battery to make sure that it is actually losing its charge (use a load tester the draw a current and measure the voltage according to the load tester instructions). If the battery has lost its charge, have the alternator tested.

Hope this helps.

08-27-2007, 12:55 PM
88 and Tranger thanks.

Tranger- pull the front bowl I assume to get to it? I did not do the rebuild, but have no issue tearing into it just want to know what I am looking for. Think I have a diagram from internet for 4160 saved somewhere. If not can locate it. Just need to run a small wire throuht it I assume. Kind of like jets on dirtbikes. We always used a bread tie with coating tore off.

Skidim for rebuild kit for alternator?

08-28-2007, 04:42 PM
Sorry for the delay in responding. I broke my ankle skiing about two weeks ago and finally had the surgery to repair it yesterday.

Your don't necessarily have to remove the front fuel bowl to clear debris from the needle valve. Unhook the fuel line, remove one of the the two lower screws that fasten the bowl to the carburetor's main body and drain the fuel into a proper recepticle (draining the fuel allows the float to drop and thereby pull the needle valve out of its seated position). Replace and tighten the fuel bowl screw. Then use compressed air to blow a few brief puffs into the fuel bowl inlet. This likely will clear the debris.

Change the fuel filters (especially the one in the fuel pump), reattach the fuel line to the front fuel bowl and start the engine to see if the problem has been eliminated. (It may take several cranks to start the engine since the fuel bowl and fuel filters will be empty.)

If the problem persists, you may need to replace the needle valve, which requires that the front bowl be removed, which is also a straightforward job. Let me know if the above-procedure does not solve your problem, and we can go to the next step.

08-28-2007, 11:07 PM
Tranger.... sorry to hear you had to have surgery. How long you out?

I will tear it apart Sat morning. Will replace the filter in the carb (have an extra on hand), and will get a filter for the fuel pump (did not know there was one there). Is that just a standard 351 fuel pump... if so assume napa will have it? Or a dealer part? I know I get oil filters, fuel filters, cap, rotor, ect at napa. Think EastTX on here put a great cross reference together.... great sheet to have.

20 Psi enough from compressor? Want to get enough but dont want to blow seals and all in carb. Blow it in where fuel line hooks up correct?

Hope this works, and with the holiday weekend the boat will get a workout!
Thanks again.

08-29-2007, 07:06 PM
Thanks for your concern. My skiing season is over for this year. I usually ski until December, but will probably wait until spring to resume my routine. I now have two screws in my tibia and am 61 years old, so I donít want to push myself too much.

Iím not sure about your í89 ProStar, but my í90 ProStar does not have a filter in the carburetor, just a mesh screen, which can be easily cleaned with compressed air. If you have an extra, by all means use it.

The filter in the fuel pump is contained within the metal bowl on the bottom of the fuel pump. The replacement filter is a Purolator F50221, which is available at NAPA and other auto parts stores. Undo the bowl tensioner located under the metal bowl, rotate it out of the way and pull the bowl off (place a container below the fuel pump as some fuel will drain out). Remove the fuel filter and the rubber gasket that seals the metal bowl to the fuel pump body and replace them with the new parts.

There is also a fuel filter in your Racor water separator, which is located on the right side of the engine bay (just follow the fuel hose from the fuel pump back and you will find it). If this filter hasnít been replaced in a few years, fine debris can accumulate in it and be circulated to the fuel pump and carburetor.

Yes, 20 psi is OK for blowing into the carburetor inlet. Just give a few short puffs into where the fuel line was disconnected. After you have drained the front fuel bowl, as described in my previous post, the needle valve will open and the air should blow out any debris trapped there.

Good luck and have a great time on the water.

08-29-2007, 07:10 PM
By the way, I just noticed that the ignition timing for your engine should be 10 degrees BTDC, not 8 degrees as I previously stated.

Sorry for any confusion.

08-30-2007, 08:06 AM
I have also heard that on really hot days, the fuel boils in the fuel line near the carb causing "hot start" problems - folks have fixed this by insulating same...I have a different motor but recall reading that tidbit of info - I think it's for your year/type of motor...might want to explore this a bit more - seems like a quick/cheap fix??

Good luck

09-01-2007, 01:38 PM
changed filter, and followed trangers advice but front venturi is still dripping. everything else seems good. starts with a bump of the key, timing right on. any advice?

09-01-2007, 06:18 PM
If the engine starts easily a few minutes after shutting it off, it is not flooding. If the needle valve were not closing, fuel would continue to drip/flow into the intake manifold for a while after you switch the engine off.

If the engine is not flooding, it sounds as though it is running too rich, based on your description of soot out the exhaust. This could be caused by a too-high float level, loose or missing main metering jet, a too-rich idle adjustment screw or a faulty power valve.

When you stated that tapping the front bowl resulted in the engine running OK for several hours, I was convinced that it was a needle valve problem and that the impact of your tapping cleared what ever was causing the needle valve not to close. I’m still suspicious that the needle valve is the problem, but your statement that the engine starts right up seems to confound this theory.

Does the engine idle, accelerate or cruise OK? Does operating the vessel without the spark arrester change the engine performance? If so, the spark arrester may be partially obstructed and need cleaning.

A certain amount of “dripping from the venturis” is normal, but both sides should be about the same. Check that the idle adjustment screws are both backed out from the seated position about the same number of turns (typically 1-2 turns).

If none of these suggestions work, you will have to pull the front fuel bowl for a closer inspection.

Good luck.

09-03-2007, 10:34 AM
Ok, T think were getting it narrowed down. Appreciate your help.

Still dripping, about a drop every second when its running. After I shut off the engine, it will continue to drip. I am assuming until the pressure bleeds off the system?

I have not run it much, except at idle withouth the flame arrestor. It still drips with it off.

We have to idle out a ways to get to open water, the plugs were about fouled, had to run it hard to get it cleaned out. I am sure they are black as can be and will change them as soon as we get this solved. I did change the oil in it this weekend, was black and smelled like fuel really bad. Had 28 hours on that oil change.

Motor runs great if its not loaded up. No hesitation, stumble, backfire, nothing. Idle air screws are at 3/4. It starts great. Seldom have to crank it much. So I know my setting are good. Just the drip is making it load up. I changed the filter. Blew air through lines each time I was in this weekend.

I do notice, may be just by chance, that each time I tear it down it will run fine untill I shut it off and restart it. So hypothetically if I blow air through lines before I go out and run it 8 hours strait without shutting it down... it will run fine. As soon as I turn it off and restart, it starts dripping again.

Frustrating part is I worked to get it tuned good mechanically, and this little drip is causing me fits! Patience.

09-03-2007, 07:32 PM
OK, at this point I would remove the front fuel bowl and replace the needle & seat, check that the float is OK and not saturated with fuel, and check/reset the float level. I would also remove the metering block and check that the power valve is not ruptured and that it is the correct one for your carburetor. I would also check that the main metering jets are firmly seated in the metering block and that they are the correct size for your carburetor.

I would also consider replacing the needle and seat in the secondary fuel bowl and also check the integrity of the float and the accuracy of the float level.

I would also thoroughly clean the flame arrestor with a suitable solvent and blow it out with compressed air.

Also make sure that your choke is wide open after the engine has warmed up. I have seen several instances of the flame arrestor rubbing against the choke plate linkage and mechanically impeding it from opening fully.