evinrude 25hp 1975 acceleration

[almosttohavana]

I have a '75 25hp outboard that runs pretty well once it gets up to full throttle. It just takes a little while to get there. How can I fix this?? It sounds like its missing maybe?? I am new at this and my terminology is still weak and for that I appologize. Any help is appreciated.<br /><br />Brian

 

[OBJ]

Re: evinrude 25hp 1975 acceleration

No problem Brian....all the wrenches here on iboats will help.<br /><br />Lets' talk about the 25.<br /><br />Does it labor coming up on plane? Shake, rattle and roll or just a labored pull to WOT? I gotta ask, how far below the keel of the boat does the gear case hang? Tell us about the boat it's on. Length and all that.<br /><br />When was the last time ya' had a tune up. Fresh spark plugs and that sorta thing?<br /><br />Yep...I know. Lottsa questions. But since this is all over the net, ya' gotta git a feel for the set up and such.<br /><br />Keep postin' dude!!

 

[Chinewalker]

Re: evinrude 25hp 1975 acceleration

Hi Brian,<br /> Is the motor new to the boat? Is the prop new? Might be an issue of too much prop for the hull and load conditions. Might be worth it to have the motor tached out (should be revving in the 5000 RPM neighborhood at WOT). If you're not reaching that plateau or a shade higher, drop the prop pitch down an inch and see where that gets you. If you have a good prop shop in your area, they may let you borrow a prop or two to find one that works right for your rig.<br />- Scott

 

[almosttohavana]

Re: evinrude 25hp 1975 acceleration

Ok all, thanks so far for the quick responses! I am going to be taking pictures today to show you what exactly is going on...but pictures cant put sounds in your head, so I am going to try. <br /><br />First to answer a few questions: I have the motor on a small 14' runabout. When in the water, the shaft goes to a bit above the exhaust. So I must mention this is a commercial outbourd, so the exhaust does not come out of the prop. I just bought the boat from an ex-coast gaurd guy who took good care of the motor. When I got the boat, I ran it for a good 1.5 hrs and she ran pretty well. I have taken the case off, removed the filter from the carb, which I may mention maybe dirty to, but I will let you tell me what to do about that. Also, It took me some learning with the high speed/idle needle adjusting. I finally have it to a place where I think it should be. Which brings me to another question...from what I have read, there should be 2 of these adjustments on my outboard, one for high speed and the other for idle?? If so, I am screwed (pardon the pun), because I dont see the other one. Just last night, I checked the spark plugs and the gaps are set correctly, and they dont look so bad. <br /><br />So on to how she sounds...She pitters she patters, she shakes and sounds like she is going to break down. But then when at WOT it takes a bit of work (pitter pattering). I can compare this to a car when you rev the engine in neutral then go back down then back up then back down. But when it feels like she made it to where she is supposed to go, it sounds great, and I am having a great time. I just get worried that it is going to be the last time I hear that nice sound and I break down in the middle of the bay.<br /><br />Put me at ease gents.