1999 200efi degraded performance

[duff]

Ok I am getting ready to look at the motor and would like some ideas of what to do and look at.

I normaly run at WOT at about 5800 RPM and GPS speed is top 64 normal 62.
during my last tournament I was running fine during prefishing the whole week before, come tournament days: Day one, hard to start (must choke and lift the lever for faster idle), slow hole shot, max speed 56, same lake similar if not better water conditions. Day two, Very hard to start (must choke and lift the lever for faster idle), still slow hole shot, and max speed 57, conditions similar but rougher water? once started it would idle a little rough. what I consider good hole shot was planeing out between 9 and 10 MPH now between 12 and 13.

the motor use to start easy and run strong good hole shot.

I am currently looking at checking compression (if good), replaceing plugs, and fuel filter, also thinking about the hose from tank to motor (going to check it to see if it is breaking down). what else should I be looking at? for the past 7 months I have been adding sta-bil in the recommended amounts. longest the boat has sat is 5 weeks with a 1/4 tank of gas. this gas was gone well befor the problem started

thanks in advance

duff

 

[Faztbullet]

Re: 1999 200efi degraded performance

must choke

A EFI has no choke...pushing in on keyswitch does nothing. From what you have posted it sounds like a ignition or electrical problem...

 

[mercury713]

Re: 1999 200efi degraded performance

did you try changing spark plugs?

2 strokes burn plugs on cold starts.

 

[duff]

Re: 1999 200efi degraded performance

well I have learned something new. should have been clear about the CHOKE it is not carberated (feel kind of dumb for that). I have owned the boat for just over a year and have not changed the plugs or fuel filter. those are both on my list to change this week. are there any checks I can make to test the electrical/igniton system? I checked the wires and they are still in good shape. I have a multi-meter to make the checks with. if there are any.

here is my list to do this week (thursday) anything else to add?

1) compression test
2) replace plugs (how offten do you recommend)
3) fuel filter (how offten do you recommend)
4) fuel line just to see if it is breaking down (tank to motor)
5) any electrical/ignition test recommended

Thank you again for all your help

duff

 

[duff]

Re: 1999 200efi degraded performance

forgot one more question? do you recommend replacing plug wires when you replace plug (I normally do on my cars)

 

[Orbit Express]

Re: 1999 200efi degraded performance

From what I've already learned, just change the motor to a 4 stroke Yamaha, you will be happy you did. You are headed for a short block +, soon.

 

[Faztbullet]

Re: 1999 200efi degraded performance

Orbit you dont know Chit.. you had a bearing fail on a 1000 hr engine likely due to poor maintenance performed on it,cheap oil or injector/ECU problem.. and all brands have similar problems.............As for the wires replace only if damaged, nicked or boots(plug end) are degraded.

 

[jeffersondodson561]

Re: 1999 200efi degraded performance

I would pull the ECM off CAREFULLY and inspect the map sensor hose, if I remember correctly the map sensor is built into the ecm...if compression is good

 

[duff]

Re: 1999 200efi degraded performance

compression was good (95-100 all 6) , did not have a chance to test run after replacing plugs and fuel filter. I also did not get to the hose inspection I had planned on doing! will be doing the hose inspection this weekend and hope I can get it on the water. will keep this post informed as to any further results.

any last minute you might want to check!!!!!

Thanks again duff

 

[duff]

Re: 1999 200efi degraded performance

Faztbullet,

Thanks for the thought on the ignition/electrical.

Any idea on how or what checks I should make to try and verify these are working correctly? or should I just be looking for the spark, and do you recommend a spark indicator or do you recommend grounding plug and looking for the spark directly? I would like to make any cheacks I can before testing the boat on the water.

Thanks again Duff