Low RPM's

[mitchell6]

Well the weekend was a flip flop, Took the boat out to the lake (1973 Johnson 135Hp)and it ran like a charm Saterday, got in it this morning and cranked it up and it wouldn't go above 1000 rpm's with the warm up lever all the way up, tried to get it to go but the same thing want go above 1000 rpm's. Just changed the water pump out and that was the first time back in the lake sence looked in the manual I think maybe it's just not getting a good seal on the water pump. Could that be it? Took off all the spark plug wires one at a time and they all seem to be fire (They'll all give you a good bite anyway's so I guess there firing). Somebody please help or should I just trash the motor and find another one.

 

[JB]

Re: Low RPM's

When you pulled those plugs did the idle speed drop with all of them? You might have lost a carb or slipped the throttle linkage.

 

[mitchell6]

Re: Low RPM's

Well droped the lower unit this afternoon took the water pump back out and redid it all over and used a new tube of gasket seal. put it on the muff's and it seem's to be ok now. it's back up to around 6000 RPM's I guess maybe that fixed it will know for sure this weekend when I can put the boat back in the lake, Might change when it's under presure but I hope not. <br />Thanks for the input JB

 

[mitchell6]

Re: Low RPM's

Well got her back in the water this weekend seem's the water pump seal was most of the problem got most of my rpm's back but now she want go above 4500 rpm's was runing at 5800 to 6000 opened all the way up I know that the compression is a little low on number 2 cylinder guess it's time to either rebuild or buy me a different motor.

 

[KYHunter2]

Re: Low RPM's

Im SURE you didn't mean , as your post indicates:<br /> <br /> "put it on the muff's and it seem's to be ok now.it's back up to around 6000 RPM's I guess maybe that fixed it will know for sure this weekend when I can put the boat back in the lake, Might change when it's under presure but I hope not." <br /> <br /> If this is true . Then your probably right , you'll need a new motor.<br /> <br /> You never want to get above 1500 rpm's, on muffs , personally 1200 rpms, is about as high, as I like to go.<br /><br /> Do a compression test , and go from there. <br /><br /> You may have done serious damage, to one or more pistons , cylinders, etc. etc. <br /><br /> How long did you run it at 5000-6000 on muffs?<br /> <br /> If your wording is misleading, and I'm wrong then ignore the above.<br /><br /> <br /> Good-Luck,<br /> KYHunter