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tried to start her yesterday. when i turned the key very slow rotation of the flywheel..dead battery right..no took brand new charged battery and same thing. maybe bad ground. took out battery and hooked it up directly to the solenoid ..same thing..then directly to the stater it self..and same thing. Thinking the only possible solution is a bad starter. I switch the starter from the right motor to the left..and same thing. I then try to turn the flywheel buy hand and find it is very hard to turn compared to the other engine. I had problems starting it the week before(same thing) but when i hooked up a charged battery it turned it over and ran perfectly. I know this is a long one, an suggestions would be appreicated. thx
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fliboi,
This doesn't sound good - you are going to have to find where the extra internal resistance is coming from.
I would drop the lower unit and turn the drive shaft to see if the extra resistance is there. If not, then it has to be associated with crankshaft, connecting rods, or pistons.
I would not run it anymore until you find and fix the problem.
Let us know what you find out.
Good luck,
Ken K -
I have the same engine and am curious how easy are you able to turn the flywheel on the good engine? or how hard is it to turn on the bad engine?
The reason I ask is because I just replaced the starter motor on my single 1987 115hp engine after the exact same symptoms....starter motor was slow to engage.
During this time I was experiencing starter motor trouble I did attempt to pull start the engine with the emergency rope and I was unable to as I simply couldn't generate enough speed from my pull of the rope. I was amazed how hard it was to pull. Now I am wondering if I was having extra internal resistance as well.
This is why I am curious how easy your good engine flywheel can be rotated.Comment
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thanks ken i will try that..good idea on the lower unit. Rmart the good engine fly wheel will turn with a good amount of pressure. Its hard to explain in words, it will spin with a good amount of force, but still feels smooth. the bad motor will spin but is not smooth and feels like your actually pushing hard.hope this helpsComment
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Thanks...that helps a lot. I was able to get the flywheel to spin when I pulled the emergency starter rope, but I don't think I could have ever gotten the engine to spin fast enough that way to start though you are supposed to be able to. Your comment just had me worried that my flywheel should have spun freely by hand let alone with the starter rope. Thanks.Comment
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rmart,
I have a 2000 C115 and just recently did some work on the starter and flywheel (had to reshape the teeth - another story). I had to grab the flywheel by hand and slowly rotate the flywheel - I could feel the compression of the pistons and the flywheel would resist turning, of course, and I just held steady pressure on the flywheel until the compression bled down.
My point is - you should not be able to easily rotate the flywheel - either by hand or rope. I would hate to start mine with the rope. I think if the motor was warm from previous running, then maybe a quick yank could do it. From a cold start - no way.
The lower the compression due to wear of the rings, then obviously, the easier to turn the motor over.
Good luck,
Ken KComment
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well ken it took me five hours but finally got the lower unit off. ended up shearing one of the bolt heads off, The good news is the motor spun great with out the lower end. the bad news is the restriction was being caused by the rubber insert that surrounds the main shaft going up into the powerhead. The rubber was completely torn up and the C-clamp that held it in was bent around the shaft. I guess my first question is 1)how important is this rubber insert( I assume it keeps the water from going up the shaft.2)Can you replace it. 3)If not can you actually buy an intermeidate housing.. thxComment
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fliboi,
Well, I am glad you have isolated the problem - could have been worse.
First of all, you see now why marine mechanics recommend you do a water pump repair every two years, on average, not only to replace a worn impeller, but to also check those lower unit bolts for corrosion. When you re-install the lower unit (I would do a water pump repair if it has been at least three years since last one), be sure and use a quality thread sealer on those lower unit bolts and water pump bolts - the Yamaha manual calls out for Loctite 572, but I could not find any locally. I did find Permatex 14A thread sealer with Teflon and have been pleased with it. Comes in small tube for about four bucks.
Hope you can drill out that sheared bolt - I've never had to do one - maybe use an easy out?
Let me know how you get it out.
As far as the rubber insert (bushing), we are in an area I am not familiar with, but I would guess its function is to keep water from splashing up to the bottom of the crank in case the water pump housing springs a leak. Water is not normally present in that part of the upper casing. I would think you could run without the bushing, but let me check with my trusted marine mechanic and see what he says.
Later,
Ken KComment
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fliboi,
Ok - checked with my marine mechanic and he said he has never had to replace that bushing - never seen one go bad - he does not know how to get it out, but I would think since it is held in place by a "circlip", it should pull out fairly easily.
I looked all thru my Yamaha manual for that bushing and could not find it - so I went to boats.net (sponsor of this forum) and looked for it in their parts catalogue - found it listed as "drive shaft bushing" and "circlip" under upper casing diagram. It shows the bushing for the extra long shaft - I guess 25" - because my 2000 C115 with a 20" shaft does not have the bushing. I would think all models would have the bushing - the only function it can perform is to keep water from splashing on the splines of the driveshaft and crank, which would invite corrosion.
My mechanic thinks you could run the outboard without the bushing - just drop the lower unit every two years for water pump repair and be sure to grease the splines on the drive shaft real good. I tend to agree, but if you can get a replacement (from boats.net), I would put a new one back in - be sure and grease the inside surface where it contacts the drive shaft.
On the sheared bolt, my mechanic says if there is enough bolt sticking out to grab with a pair of vice grips, then heat the bolt with a blow torch and tap lightly with a hammer to loosen the corrosion and then try to turn with the vice grips. If that doesn't work, then you will have to drill it out. Center punch the sheared bolt as close to center as you can and start with a small bit, and gradually increase size of bits until all of the old bolt is removed. You will have to go one size over on the bolt - so you will have to tap for it.
Now, my mechanic also says that if you do not want to go to the trouble of removing that stuck bolt, then you can get by with just one missing bolt out of seven, if it is one of the three side
bolts. He has seen the seven bolt lower units run before w/o one side bolt with no problem. If I were you, I would try to get the old bolt out, but then I am a perfectionist when it comes to things like this - I drive myself crazy sometimes, because I am very analytical and precise about the technical world around me.
Let us know how you come out.
Good luck,
Ken KComment
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well ken it was another long day in the heat working on the boat but shes done..got the bushing out after about an hour, that c clip your talking about was bent around the shaft and stuck in the rubber in the bushing. ice picked worked great getting it free. cleaned all the corrosion out and $35 dollars later for the bushing and a mallet to get it backing in and she was perfect. did the water pump for the hell of it. ran perfect.I was told the bushing is there to keep any vibration in the shaft down. thanks for the help. talk to you next feasco.Comment
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fliboi,
Glad you got her fixed - what did you do about that sheared lower unit bolt?
Ken KComment
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remarkabley i let it sit overnight with some penatrating oil, and with a couple turns each way with a big vice grip she came right out. I was surprised myself.Comment
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fliboi,
What is the name of that penetrating oil?!!!!
Ken KComment
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honestly ken i was pretty surprised myself. The oil was nothing special i picked it up at lowes. Was called mechanics friendComment
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