# 25 yamaha ,won't turn over with plugs in



## jmrodandgun (Sep 20, 2013)

Maybe some type of critter has made a home in the intake or exhaust. Perhaps a sticky valve.


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## Mako 181 (May 1, 2020)

2 Smoke Motor - No Valves
Pull plugs and put a little oil in in cylinder. Pull it over and see if it frees up.
Make sure in Neutral - Spin the prop


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## lemaymiami (Feb 9, 2007)

A little light lube in each cylinder, turn it over a few times without plugs in place - then fire it up... I'm betting that your fuel system (from the tank to each cylinder) is probably gummed up as well. Empty it out completely, go with fresh fuel and if you can get it to fire it will clean itself if the carbs aren't too far gone... You may end up having to re-build the carbs and for that I'd want a pro... Post up how it comes out... and I'd expect a cloud of smoke the first time it fires up.. 

Aren't boats fun?


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## GSSF (May 25, 2013)

Shoot some Marvel Mystery Oil in the cylinders and let it sit for a few hours. Then as others have said, turn it over. Slowly at first. Follow up with some BRP Engine Cleaner or Mercury Power Tune into the fuel supply/carbs once you get it to fire. 

Fresh fuel with a dash of Mercury Quick Care additive and I bet you'll be in business.

I have no affiliation with any of these products. Just what has worked for me in the past as recommended to me.
Good luck!


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## krash (Jan 9, 2007)

From your explanation it sound s like with the plugs removed it turns over easily... problem presents itself when you install the plugs.
Disconnect your fuel source, drain the carbs, spin it and Measure the compression of each cylinder ?
Go from there.. depending on the compression.
If it looks reasonable.. clean fuel system & carbs, if its oil injection clean that system, start and run it.
If not, consider top end rebuild or mechanic.


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## cnovel (Oct 28, 2021)

thanks everyone !!! yes without the plugs it pulls very easily , like it should , pistons are free,and always have been , I tried putting 1 plug in at a time,different cylinders,2 plugs at a time ,again trying different cylinders , each time it is tough to pull ,and not smooth . cooler weather (and wet) is coming so i have it inside , going to clean up the exhaust side,,surface corrosion , I am waiting to receive gaskets so I have them in hand before I take anything else apart. 
would the lower unit have any effect on this ? prop spins freely in neutral,not in gear,,might pull that off the check impellar out anyway ,,drain carbs,, thanks for the thoughts !!

motor has always been great, we have harvested tons of oysters, specks,crabs,redfish, and ducks on the texas coast,even used in 2 hurricanes , bought a cabin in western NC , and want to start chasing striped,and bass now,,get it ready for springtime 

thanks again !!!


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## cnovel (Oct 28, 2021)

lemaymiami said:


> A little light lube in each cylinder, turn it over a few times without plugs in place - then fire it up... I'm betting that your fuel system (from the tank to each cylinder) is probably gummed up as well. Empty it out completely, go with fresh fuel and if you can get it to fire it will clean itself if the carbs aren't too far gone... You may end up having to re-build the carbs and for that I'd want a pro... Post up how it comes out... and I'd expect a cloud of smoke the first time it fires up..
> 
> Aren't boats fun?
> [/QUOT yes, they are,nothing like a nice boat ride , ive worked on many boats all over the world, it is much more enjoyable when they are running right !!! thanks


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## permitchaser (Aug 26, 2013)

You’ll get it fixed. Hope your feeling better


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## cnovel (Oct 28, 2021)

thanks, it has just been crazy,,6 months of chemo, virus came during 2nd. month ,,in remission,,but then have the carpal tunnel surgey on my "pull cord" hand ,,,during chemo my heart rate started dropping , so I have a pacemaker now ,,( 6 weeks) so I just tackled to problem,,,this morning I can pull it with plugs in , so I am going in the right direction,just thought I would ask for any and all helpful hints,,craig


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## Hank (Jan 14, 2019)

If the carbs are leaking, the crankcase might be full of gas. That will keep it from turning over. Leave the plugs out and get a friend to pull it a bunch. And if you're smelling gas as this happens there is a good chance thats the issue. Pull it a bunch and give it a chance to dry out with the plugs out overnight. If this is the problem you probably need to have the carbs gone through so it does not happen again.

I hope your health continues to improve!


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## cnovel (Oct 28, 2021)

Thanks everyone for the advice !!


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## krash (Jan 9, 2007)

Just a thought, have you tried starting it ?
Maybe it just needs a good cleaning.

Perhaps it just seems harder than you remember. I've had my share of health issues went through heart valve replacement (mitral & aortic), been thru 3 different pacemaker's to get one that worked which included defib, then a few years later heart transplant.. after full, or what I consider full recovery I feel great conpared to the last few years..
But now when I try to do things i used to just do, like cut the like pulling the mowers start rope, picking stuff up, or my light workouts I'm just not as strong as before. Even working on the car, motors or stuff truning wrenches ain't the same. (Just a thought)


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## cnovel (Oct 28, 2021)

Glad you are better , No I have not tried to start it again,it was locked with the plugs in , I took off the exhaust cover and it looked really good with minimal corrosion after 20 years of salt use ., but while I was there,,cleaned it up,and I am now waiting for gaskets, to put it all back together . it will pull now,although like you said it feels harder,,my pacemaker got infected , so the glue over seam where they put it,,is just now healing up ,,I will check out the carbs while I wait for gaskets,,as well as check the lower unit . It sucks to get old


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## 17376 (May 5, 2017)

Or let me know where I can pick it up at and I'll be glad to take it off your hands.


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## Dadvocate (Jun 26, 2011)

Glad you are doing better health wise. Welcome to the Pacemaker club. When you get it running maybe you can convert it to an electric start. Best wishes.


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