no power at wide open

[timcoffin]

I have a 1988 bayliner with a 50hp force runs and idles good had carb cleaned and changed plugs and new gas, when throttle is wide open boat only goes around 10-15 mph,and only sounds like the rpms are at 50% not like it is wide open checked carb throttle opens wide open ,checked reeds, and compression around 125 both cyl. When boat is not in gear,I can rev the motor up,and sounds like the rpms are there but in gear its only 50% please help find the problem thank you.

 

[i386]

Re: no power at wide open

You might be running on one cylinder. Check your ignition. If it's good, at least you can mark that off the list.

 

[john from md]

Re: no power at wide open

Also check your ignition timing. If you open up the carbs without advancing the spark you will not get the power output that the engine is capable of.

Regards,

John

 

[Kidmon]

Re: no power at wide open

I have the same exact problem with my 88 50hp force. My problem tested out to be a bad "Trigger". The engine was running on only 1 cylinder and on my pontoon boat I was able to manage only 7mph. It seemed to run ok it just had no power and idled a bit rough. I pulled the spark plugs to check if each cylinder was firing and found one cylinder was not firing . If you dont have a manual yet GET ONE. I like mechanics on engines but the electronics on this engine was a bit of a test for me with all the volt and ohm meter testins we had to do to identify the problem. The "Trigger" was ordered from Seattle Marine" 1-800-332-0803 and the guy gave me a great deal on it. With freight and taxes it was about $125 bucks. (Get a "CDI" after market Trigger if yours is bad) Another cause for your problem might be a bad coil. There are variuos types of "ignition systems" on the same engine so make sure you know which one you have. Mine was a "Prestolite". Check on top of the flywheel for ignition info. If you are not careful this could be a $500-$1000 repair that you could have done for $100-$200 dollars. OEM pricing for the componets get pretty high.
Trigger About $175, Each coil about $200, Stators about $225 and then there is the labor of the shop, any where from $50-$100 an hour. All of these componets can be replaced in about 2-4 hours depending on the mechanics skill level. $35 buck spent on a repair manual will save you hundreds of dollars and you get to know your engine alot more which is a great confidence builder (or not) when you are on the water.
Good luck and happy boating
Ken

 

[timcoffin]

Re: no power at wide open

thanks for some ideas ,checked spark,ok both cyl.runs smoothe but no power need to get manual. thanks

 

[timcoffin]

Re: no power at wide open

ran,tried to figure it out,got back home still no power checked plugs ,they were black and oily is that normal, thanks Tim

 

[Kidmon]

Re: no power at wide open

Time to get serious.
Some light "Oily condition" is normal, Black is not.
(Fuel mixture 50:1 w/ Outboard oil right?)
1. Gap the plugs unless they a the "Gapless" type.
2. Check the vent on the "Gas tank"
3. Check the Timing.
4. Replace the fuel pump Diaphram. (Clean inline Filter?)
5. Use a Tachometer for true info.
6. Use an Ohm/voltmeter and test the ignition componets.(Book is Required)
A. Test the Primary & Secondary side of the Coils for Resistance
B. Use a "Spark Plug tester" (Plugs firing under compression?)

7. What ignition system?
A. Motorola
B. Prestolite
C.Thunderbolt
D. ??
8. Is the "Lower unit" free or dragging (Change the Fluid look for "Shavings")
9. Change the "Impeller" (Check for free shaft movement when you do this)
10.Get the book, Really, it will make your life easier.
Good luck, Let us know what you find
Ken