compression for 75 stinger johnson

[stinger700]

we checked the compression and the #1 is at 123, #2 is 120 and the #3 is 118 lbs. what should it be? also we have a weird problem.<br />we checked the reeds and they SEEM to be in good shape. the #3 carb has no suction when the motor is running. The number 3 also has excess fuel in the carb. the spark plugs are working. (the coils are old and cracked but they are not arcing. We have new ones orderd. what gives? how tight should the reeds be?

 

[Saskatoon2005]

Re: compression for 75 stinger johnson

Please give us the year and model number so we can better help you....<br /><br />Does it start? The carb not sucking could just mean that it needs a rebuild. Start with changing the coils and then let us know more....

 

[CFronzek]

Re: compression for 75 stinger johnson

Stinger, <br />That doesn't make sense. A cylinder w/118 lb has a good piston and ring set. It is obviously going up and down. For it not to have any suction seems impossible.

 

[Walker]

Re: compression for 75 stinger johnson

The only way to lose suction in your case would be a bad reed/reeds, airleak behind the carb, behind the intake manifold, or bottom crankcase seal. <br />I like to check suction with a piece of tissue held in front of the carb throat. That will tell you if the reeds are leaking too. Bad reeds will blow the tissue away.

 

[stinger700]

Re: compression for 75 stinger johnson

sorry we did not get back sooner. it is a 75 year model. the motor does start and run, however when you advance the throttle under load (in the water) it does not accelerate, it bogs down, when you have it in nuetral and rev it by hand or have it out of the water and in gear it revs on up. We did have it run great in the water one time for about 200 yards and then it started to bog down again. we checked all the NEW fuel system; from the tank to the fuel pump and did not have any problems. the carbs were rebuilt by us, after some advice by a mech. <br />we took the reeds off last night and did find one reed that you could see day light through on the bottom carb. now this was 1 out of the 6 reeds and it is very slight; is this a problem?<br />should have checked the suction problem with a tissue we did not will have to get new gaskets now before we put it back together.<br />HOW can we check the bottom crankcase seal? this seems to make since, because the top piston seems to be making the most power and then the #2 and then the bottom. (we put our hand over the intake with it running and this test seem to indicate this) the bottom had no effect on the engine when we put our hand over the carb.

 

[stinger700]

Re: compression for 75 stinger johnson

one more thing, the fuel line that runs from the fuel pump to the bottom intake is this for suction?<br /><br />thanks guys for your help, I have to fix this thing by my self. my summer job does not pay much so ya'lls help is much appreciated.

 

[Dhadley]

Re: compression for 75 stinger johnson

You're kinda describing 2 problems we've seen with those motors. Let's look at the bogging at high rpm for a moment. When you do get it to take off and run good, when it starts to bog down have you pumped the fuel bulb?<br /><br />You mentioned you rebuilt the carbs. Did you put in new kits?