no power?

[mystixx]

have a mariner 100 hp a 93 . 4 cyl . just rebuilt . ran fine for a few hours and now it has not pickup or wont get to top speed .<br /> runs fine when it gets up to speed . just wont hit top speed . and very long for take off . any ideas to look at ?

 

[petryshyn]

Re: no power?

ouch...<br />>sounds lean...<br />>how does it idle?<br />>if you slowly accelerate, can you hear a cylinder or two drop out?<br />>have you squeezed the ball hard while accelerating?<br />>maybe some garbage passed through fuel system, plugging main jets off?<br />>have you rechecked compression?<br />>don't think I'd run her too much until problem solved(lean=bad)<br />>might want to redo carbs to be sure...<br /><br />*lots of variables here, ignition can be dropping out as well....

 

[mystixx]

Re: no power?

idles great at least sounds fine .and when running at the top speed it will go still sounds fine . if ya take off slow it just bogs out and no pick up ..

 

[petryshyn]

Re: no power?

being as you said it ran good at first, I assume there are no timing issues.<br /><br />It sounds lean. If you continually squeeze the primer ball and keep it hard, you will eliminate the fuel pump, filter and valving. If it still bogs while doing this, I'd go through the carbs. You don't want to run lean for long, or you'll be overhauling again. (If the ball won't get hard = bad ball or restriction between ball and tank. Could even be a venting problem)<br /><br />Don't know about yours, but if you remove air box or shrowd from infront of carbs, when bogging under acceleration, look down the throttle bores with a flashlite and you may see one carb not supplying a white froth. That would be the one I'd question.<br /><br />(make sure some is driving!!!and you should be teathered incase the carb clears!!!)<br /><br /><br />

 

[JB]

Re: no power?

Sounds to me like it's making power with two or three cylinders, Ray. Ground plug wires, one at a time, while idling. If rpm drops that cylinder is making power, if no change that cylinder is not making power.<br /><br />Red sky at night. . .<br />JB

 

[mystixx]

Re: no power?

did compression test all 4 at 100 or so . i will try the plug thing and will look at the gas will be back soon thx .

 

[tlynch]

Re: no power?

Hey Guys,<br /><br />Are there symptoms which point to a Carb / Fuel issue as opposed to an electrical issue?<br /><br />For instance, if an engine slowly dies out would you think that it is a carb problem and if it happens suddenly you would think that it is an electrical issue?<br /><br />Or maybe if it happens while running at high RPM's would you think that it is electrical because once a carb is running at wide open it tends to keep working, but if it happens while accelerating it might be a carb issue?<br /><br />etc...<br /><br />You guys have tought me how to test to see if it is an electrical problem but from the symptoms of a problem I would like to learn how to tell what it might be.<br /><br />Thanks,<br />Todd

 

[mystixx]

Re: no power?

well its been a while since last post found problem it was junk in carb #3 thanks for the help guys. so now its very cold here in florida . so i put a new floor in the boat this week . now need to wait for the weather and try it out . thank again for the advice you all gave .