Re: Help My DT75 suzuki is a pain, runs poorly
Go to the bottom of this web page and buy a manual for your year engine. You can buy parts online at
www.brownspoint.com and you can also download the exploded parts diagram. The principles are the same as the autos but there are some differences. Your engine is oiled by an oil injection system that injects oil into the fuel system beyond the carbs not with crankcase oil, so oiling is critical. Also, 2-strokes are very sensitve to lean fuel mixtures because the fuel cools and lubricates the engine and too little fuel (even with oil injection) can burn a piston or bearing. Thats one reason why you need to keep the carbs clean (On the inside not the outside). Boats tend to sit a lot compared to cars so deposits tend to build up in the jets and orifices and require more frequent carb rebuilds/cleaning. The Mikuni carbs on your Suzuki like to be kept clean, so go ahead and order the rebuild kit, you'll find it quite simple compared to a Holley. Remove it, completely disassemble it, clean it with solvent and compressed air, and reassemble it with the new parts (basically a new float valve and some gaskets). The idle air mixture screws on the Mikuni carbs meter air so unscrewing it lets in more air and leans out the idle mixture. <br /><br />Do a compression check on the engine to check the health of the cylinders, all should be within 10% of each other. Fix the diaphragm on the fuel pump. The tear in the diaphragm which caused your engine to fail is probably injecting raw fuel into the intake port of the cylinder to which it is connected causing that cylinder to run rich and die. One more thing, you should drop the lower unit and replace the water pump on a used engine unless you know the previous owner has documented a recent (within a year) replacement. Don't tune the engine in the driveway. The 2-stroke needs the backpressure of the water on the exhaust. Tie it up to a dock in the water and tune up the idle with the engine in gear.<br /><br />If this engine has good compression, you will have a good and reliable engine and you will be able to do the above maintenance when necessary. There is a light at the end of this tunnel and it is the beginning of another sunny boating season
