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Evinrude 75 HP 1983

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kdxman

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I bought this 18.5" boat with a 75 HP outboard model 75TRLCTE in spring and went on the lake 5 times. Everytime, when I start the motor with the High Idle lever up, it immediately runs like it is going full speed. When i bring the lever down and put it in forward or reverse, it sounds better. Do I have a stuck throttle, do i need to adjust the idle screw or perhaps there is something else?

I have it on muffs right now if i need to check something.

Thanks guys
 
Sounds like you are pushing the high idle lever to far try only pushing it until you feel a little resistance. Sounds like it is working right. Do you have a tach? When idling on muffs your idle speed should be between 1000-1200 RPMS
 
I dont have a tach. At first without the lever up at all, it sounded OK but as i was stopping to film, it started reving for no reason so i filmed it for another bit before shutting it off in case its doing something tomy motor..

https://vimeo.com/180421284ref=em-share
https://vimeo.com/180421355?ref=em-share
 
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I know nothing about boat motors...Do you have the manual for the boat or a diagram with what i would be looking at when it comes to fuel fittings, carb linkage, throttle plates, etc

Thanks!
 
Get a factory manual for your motor worth every penny. And it sounds like it is on 2 cylinders. To pull the idle down see if the throttle cable is loose. On the motor find the adjustment nut for the throttle cable, make sure it is pulling the throttle assembly tight against the idle nut. There is another possibility is that whoever sold it to you knew it was running on less than 3 cylinders and turned the idle up.

The steps you need to do right now are.

#1 Compression test good compression shoud be 125 PSI +
#2 Open air spark test spark needs to jump 7/16" gap

Report back with those values and get a tach
 
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Ill give that a try. So you think its reving that high for no reason because its on 2 cylinders instead of 3?

i prob wont be able to afford a manual/gap tester/compression tester until spring so i was hoping to take it out for a last time next weekend. Is it OK to run on 2 cylinders?
 
I don't know why the idle is revving like that. I wouldn't run it like that because shifting like that can wreck the lower unit That is big money.. Gap tester is less than $10. A compression tester can be rented from any autoparts store.
 
do not run it on 2 cylinders you might ruin the third cylinder running it too lean,meaning possible unlubricated cylinder,ring damage,piston damage,cylinder wall damage IE. scoring
 
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