carb tune-up/cleaning

[joered]

i have a 98 johnson 90 HP and there seems to be some hesitation (plugs are good). thought it might need a carb tune-up, but i do not feel i need a rebuild. does anyone recommend an efficient yet not very labor intensive process for cleaning carbs or tuning?

 

[Dhadley]

Re: carb tune-up/cleaning

Hesitation? Most likely from some gummed carb circuits? Could be. <br /><br />Gummed up carb cirduits means its running lean possibly. Pistons can react very violently to lean running conditions.<br /><br />No matter what you do, the easiest, simplest and best thing is to clean the carbs and install new kits. On a crossflow its one of the simplest things to do. Kinda fun actually.<br /><br />Which spark plugs are you running?

 

[87Aggie]

Re: carb tune-up/cleaning

DHadley, I'm thinking about rebuilding the carbs on my 1977 Johnson 140. It's considered a crossflow, right. I've got an OEM manual and it appears to be fairly simple. It take two carb kits, right. Two of the same one?

 

[cobra 3.0]

Re: carb tune-up/cleaning

Try some Seafoam or OMC Engine Tuner in the carb throats while its running. Also, if there is no improvenment, open up the float bowl and spray clean this area. If it doesn't work, you need to clean the carb by dismantling it and spraying all thre holes and ports with carb cleaner. (I have yet the need to buy a carb kit...I guess it depends how much you run your engines.)

 

[TPD211]

Re: carb tune-up/cleaning

As a newbie boat owner from several months ago I was faced with the same problem. <br />The used 88 Spl. attached to a deck boat bogged down and would not run WOT. Low to mid range RPM's were ok. Evidentialy the boat/motor sat for a number of years following the original owners death and the estate was tied up. <br />Subsequent owner didnt clean the carbs as he was content to idle around the lake with his wife. This was a elderly couple. Anyways, I bought the deck boat from them. It ran fine at first then it started bogging down. I posted my symptoms, and the forum responded. Clean the CARBS was the universal response. I took the carbs off, it was kinda fun. I took them to a marine mechanic around the corner from me for a complete disassembley, cleaning, etc. Since I did the hard part, he just charged me 50 bucks to rebuild both carbs. I reinstalled them, boat runs like a charm. Power is smooth all thru the power band.<br />A big plus is that I gained the confidence to do this again and I feel comfortable diving into the carbs should a problem arise. <br />I changed the lower unit oil, putting in synthetic. That was way easier than it appears to be. <br />My next project will be to change the impellor this summer. <br />I also de-carbed, but that did not clean out the jet passages.