99' 115 Johnson sputters, & bogs

[Mopardan]

We have a 99' Johnson 115 that runs great over all, but last summer it began to sputter "sometimes" @ close to WOT. It also seems to have lost its grunt pulling up skiers and tubes. Changed plugs, and fuel filter. We can still use it, its just frustrating not have the power we once had. Any help would be appriciated. We are planning a camping / boating trip for spring break.

 

[tashasdaddy]

Re: 99' 115 Johnson sputters, & bogs

have you check compression and spark with a spark tester, should jump 7/16 ". do you run seafoam in your fuel. when were your carbs last clean. was any work done to the motor prior to it loosing power.?????? Do you have a service manual? don't use it till you find the cause. could do major damage.

 

[Mopardan]

Re: 99' 115 Johnson sputters, & bogs

Have not checked the spark and have not used seafoam. Ran several bottles of carb cleaner thru it last fall, but didn't seem to help. We bought the boat in July 2005 and has been flawless until last fall. We haven't had it serviced, or carbs cleaned since we bought it. Not sure of service history before 2005. Just crusing around @ 3000 to 4500 rpm it runs great? Headed to work, check back later.

 

[tashasdaddy]

Re: 99' 115 Johnson sputters, & bogs

it is due for service, 1 water pump service, every 2 years, 2 carb cleaning, gas not treated will vanish up and clog the jets. do you have a fuel/water separating filter? built in gas tank?

 

[Mopardan]

Re: 99' 115 Johnson sputters, & bogs

Not sure about the water/fuel separator. It does have a built in tank, that is built under the sub floor. I can't even find it! The boat is a 99' Larson 186 SEI F/S. I know a local mechanic who likes Merc's, but will work on Johnson. I may have to give him a call. Thanks for your help, and suggestions.