1987 suzuki 175

[jchomer]

I have a1987 suzuki 175 that wont run. It is a bear to get started,when it does start it will idle rough but when you put it in gear it spits and spudders and dies.Once you finally get the thing going it runs great,but as soon as you shut the thing off you have to go through the hole ordeal over again,Any help would be appreciated.<br /> THAKS JOHN

 

[ThomWV]

Re: 1987 suzuki 175

Carburators. Clean them. Then check the setting on the throtle position sensor. I presume you have changed the plugs and checked the coils to at least see that they are fireing already.

 

[jchomer]

Re: 1987 suzuki 175

Yes firing on all cylinders,like i said once you get it started and going it runs like a dream.61 mph,by gps ,so motor runs once you can get it there.Thanks for the reply i will check the throtle position sensor.

 

[jchomer]

Re: 1987 suzuki 175

Im new to all this ,so let me ask ya this ,where and how to you check the throttle position sensor,and what spark plug and gap should i be running.I begining to think i need to see a proffesional. THANKS JOHN

 

[mrn714]

Re: 1987 suzuki 175

Youneed to clean the carbs out, front to back first,, then deal with the positiom sensor. Use ether and gas to clean them. High pressure air, blow them out, check the floats, pull all the fuel pins, jets out, clean it all like new, then try. The motor should crank within seconds. If not, try to spray a light mist of fuel into carbs.

 

[ThomWV]

Re: 1987 suzuki 175

Look for this: If you remove the spark supressor and look into the carbs you'll notice that directly under the throtle butterfly there are a series of 4 offset holes, just pinholes, in the bottom of the throtle bore. It is through those holes that additional gas enters the system at idle and low speeds (high speeds as well but it has very little effect there) and is what allows you to idle as well as make a smooth transition to higher speeds. They clog up very easily. Take a short section of stainless steel leader material (solid wire) and bend an "L" into it and then use it to try to clean the small holes. <br /><br />These holes are connected to what is sometimes refered to as the air-bleed screw (some folks call it the idle adjustment) by a very small internal passageway. Sometimes you can remove the screw and give a small blow of high pressure air through it to clear the passageway and the 4 holes. Of course if you remove the carbs to do the cleaning (which is how you should do it) you will blow this passage out. I am almost certain that it is what is causing your problem.<br /><br />The throtle positon sensor is located on the lowest carb. It is controlled by the movement of the throtle butterfly's shaft. The bottom carb has a longer shaft than the other carbs and it extends past the end of the carb and drives the position sensor. There is a small plastic gear on the end of the shaft and it drives a quarter gear on the sensor which in turn changes the resistance in a line that goes to your electronic ignition. This resistance in the line, who's level is a function of the throtle positon, is what controls your spark advance. If its off you will never get the engine to idle but it will run just fine at top speed - if you can get it started and get it up there.<br /><br />Thom