Suzuki DT55 won't run over 9mph

[orrenk]

I'm sorry but I'm new to this and the world of boating with a DT55. The engine is a 1988 and ran like a top. I have been fishing with it and slow trolling with it.
I went 3 days without ever running it above 5 mph early in June. When I cracked open the throttle it coughed and sputtered and had no power. I changed plugs--new NGK's and it ran great. I've used it every week since then with no problems. Last week same thing happened again. I changed plugs again but that didn't make any difference. I fired it up in a tank yesterday--great water flow out of exhaust and peehole. Engine only got mildly warm. Spark to all 3 cylinders--when i pulled the wires while it was running you could tell each one of them was off--i also got the s--t shocked out of me on all three wires as spark was jumping--but only when the wire was not attached. I've ordered a fuel pump diaphragm kit. Any help ideas or suggestions would be greatly appreciated. Thanks in advance and I apologize if I got this in the wrong place.

orren

 

[waffles1]

Re: Suzuki DT55 won't run over 9mph

Hi Orren, I always start with a compression check and go from there. It sounds to me like your carbs are need of a good cleaning. What does the inline filter look like? has the boat sat for awhile?

 

[orrenk]

Re: Suzuki DT55 won't run over 9mph

Thanks for the suggestions. The boat actually has been being used at least twice a week for about 3 months now. My son went through 6 tanks of gas in a weekend about a week before the 4th. Compression is good--don't have a guage anymore but blow your finger off the hole good. Motor has always run strong. Today I took it out--it ran great again--no problems at any speed. The only thing that I know that I did different was the other day when I originally posted, I cleaned the plugs again and also pulled the filter out of the tank and blew it all out. I didn't thing the filter looked very bad at all but maybe it was just bad enough. Anyway, I was thrilled that it ran strong today. I will go ahead and change the diaphragm on the fuel pump and put a new filter on the motor when they come in. Thanks for the assistance. Orren

 

[jrtrpp]

Re: Suzuki DT55 won't run over 9mph

Something similar happened with my DT85. It would run like a champ for a half hour (until the ignition coil got hot) and then I would loose power and couldn't go over 5mph. The ignition coil was bad. The spark looked good to me (even though it was shocking the crap out of me) but I guess it wasn't good enough for the engine. If it does this again pull the plug caps off one at time while your under way and the engine is acting up, if you pull one and it has no effect on the engine and its shocking you like crazy (like it did to me) chances are its that ignition coil. If you pull a cap and the engine dies (or tries to) that is a good coil. Gluck.