25hp runs for 10seconds

[anthony115merc]

i tried starting my 25hp merc i cleaned my sparkplugs and put them back in and tried starting nothing so i put a bit of fuel down the carby and tried it worked for 10 second then stopped so i tried pulling the rope again and nothing more fuel down the carbys and it went for another 10secs its an 83 25hp merc 2cyl forward controls.

could it be that the fuel mix is not right? i put a little extra oil in because its been 3yrs since last run

or somthing else? i am thinking somthing to do with the fuel because it works when i pour fuel into it the priming bulb goes hard and if i continue to pump when hard it shoots it out a little hole on top of the carb

 

[tashasdaddy]

Re: 25hp runs for 10seconds

the carbs need to be total cleaned and rebuild kit installed. the fuel jets in the carb are clogged with old gas that has turned into varnish. thus the engine is not getting fuel.

 

[anthony115merc]

Re: 25hp runs for 10seconds

do i just take it of and soak it in carb cleaner? then put it back on with new gasket?

 

[tashasdaddy]

Re: 25hp runs for 10seconds

no, you need a manual, it's has to be completely disassembled. cleaned, blown out with compressed air, then reassembled with a new rebuild kit. then installed and adjusted. i don't think you are experienced enough to tear into it. don't ruin the motor.

 

[anthony115merc]

Re: 25hp runs for 10seconds

can i just spray some cleaner in there without puling anything off?

 

[anthony115merc]

Re: 25hp runs for 10seconds

i sprayed some cleaner in the carb and ran it its still not running the best but it seems to run alright

 

[j442w30]

Re: 25hp runs for 10seconds

Carb cleaner will not do much, if anything to help your situation. Most times it's just sprayed straight down the carb throat and ends up in the engine, not near the bowl, float and jets where its needed. If you buy a manual and are somewhat mechanically inclined it's not too difficult to rebuild them, but sometimes you have take quite a few other parts off to even get at the carbs.

 

[anthony115merc]

Re: 25hp runs for 10seconds

i can get to the jets from the front its a wierd carb there was no plastic grill on the front aswell it seems to be clean it sorta sounds like its getting a back fire every 10secs

 

[tashasdaddy]

Re: 25hp runs for 10seconds

yep, dirty jets, is it coughing or sneezing? one is rich, one in lean.

 

[anthony115merc]

Re: 25hp runs for 10seconds

i went and saw the mechanic next door today he told me to richen it up a little and give it a good run and set it where it goes best no different to my model planes

 

[Windykid]

Re: 25hp runs for 10seconds

Thats all good if you get it running. Listen to TD rebuild the carbs or have it done. It needs it it or you wont have ant reliability

 

[anthony115merc]

Re: 25hp runs for 10seconds

i dont want to get to involved with it so maybe i will tell the next person to own it. i just want it gone now

 

[Windykid]

Re: 25hp runs for 10seconds

Anthony, If you take your time and follow the manual, it will be very rewarding to rebuild the carbs and make it run.

 

[jimlad]

Re: 25hp runs for 10seconds

dont spray carb with that stuff waste of time and money and thats the worst thing you can do the carb needs fuel and oil in it there is no lazy way of doing this clean the carb properly and manually i use fuel and a pin to clean the jets DONT MAKE THE HOLES ANY BIGGER THAN WHAT THEY ARE ITS NOT HARD YOU MUST GET A MANUAL IT WILL KEEP YOU SAFE

 

[Jugfisher]

Re: 25hp runs for 10seconds

I understand wanting to save money if you are trying to sell the motor, but if you dont have the carbs cleaned and rebuilt it could come back to bite you in your rump. I also understand if you dont have the time. If you can find a good mechanic they can normally do this for a relatively inexpensive price and will be well worth it to save you the headache later down the road. You can tell the new owner that you just had the carbs redone and maybe get a better price for it.

 

[hkeiner]

Re: 25hp runs for 10seconds

Cleaning the carbs is the right thing to do. However, if you are not prepared to do that as this time, there is another option you might consider...​

Add a strong dose of Seafoam (say, one 16oz can per gallon of fuel) to your fuel. Let the motor run at slow speed for 10-15 minutes and then shut if off for 30 minutes or so. Run it again at slow speed for 10-15 minutes and shut it off again. Letting it sit overnight between runs is good too. Repeat this until you use up the Seafoam mix. This might clean things up enough to get the motor running OK. However, there is always a risk that it might loosen up gunk in the wrong places and clog the carbs up worse. You take a chance.​

Use a spare 3 gallon portable tank to do the above. This way you can switch between Seafoam mix fuel and regular fuel as you like. Also, you can control the ratio of Seafoam to fuel better, as compared to using a gas gauge on a larger tank. This process also decarbs the motor. There are lots of threads in this forum discussing the various ways to use Seafoam.​

 

[anthony115merc]

Re: 25hp runs for 10seconds

i will look into getting some of this sea foam stuff i might keep the motor for a month untill i get my new hull maybe can take it out for a good run after done just to make sure its all ok