Yamaha 2 stroke flywheel puller?

[bojin5]

Hi all,

I'm hoping someone can advise me. I recently had to repair the recoil starter on my 5hp yamaha outboard (about 5 years old), a horrible springy business. Whilst I was in there I noticed that the fly wheel case has become loose (I had noticed some grinding noises and think this is the cause), I think it's held to the block using 2 bolts under the flywheel so I need to take off the flywheel to tighten them. My questions are:

Is it just the large central nut that secures the flywheel?
Secondly do I need to use a puller to remove it?
Thirdly where do I get a puller?
And finally do you think I should just give up and take this to an engineer? /forums/images/graemlins/frown.gif /forums/images/graemlins/blush.gif /forums/images/graemlins/ooo.gif

Thanks

Benjamin

 

[Spars]

I have a 5 hp Marina and I think they're much the same so when I removed the flywheel I undid the central nut and used a puller to shift it, needing a shart tap with a hammer when it's tensioned.
I bought a puller from Screwfix as there's a depot nearby for I think about a tenner, well worth it so DIY.

 

[Cliveshep]

You might find that if you loosen the nut a turn or so and, pulling up on the flywheel at the same time you give the nut a smart wack with a hammer the flywheel will come loose. They most often do. If not, don't destroy the nut by repeatedly hammering it, get a puller!

 

[VicS]

Not sure about Yamahas but I think you will find that once the nut is removed you need a puller to pull the flywheel off the taper (dont lose the key that's in there as well)

I think you will need what is known as a "harmonic balance puller" (dunno why its called that) anyway its one that bolts onto the top of the flywheel with high tensile bolts. If you try to use a three legged gear puller that hooks around the edges you may damage the flywheel.

Be sure to tighten the retaining nut to the correct torque when refitting. If you leave it too lose you'll shear the key possibly.

Tool hire shops should have the puller but it may well be worth buying your own high tensile bolts just in case some joker has substituted ordinary ones.

Likely to need a sharp tap from a decent sized hammer once you have put some load on the puller.

 

[Heckler]

The flywheel is a made up component I think. From memory the flywheel is rivetted to the tapered hole boss that is fixed to the crankshaft by a nut. Undo the nut, get a puller, fix it to the flywheel, tighten it up, a smart tap on the puller bolt and it will come loose, dont lose the key!
Then comes the hard bit, if the rivets have come loose then you will have to grind/drill them out, get some bar of the right diameter, cut to size and re rivet it together. NOTE, it is highly unusual for the flywheel to end up in this condition and a workshop would fit a new component.
Stu

 

[bojin5]

Thanks all for the advice.

Stu, it's the case around the flywheel that's come loose, not the actual flywheel fixings, they all look good.

 

[Lakesailor]

I made a flywheel puller using the centre bolt and yoke from a 3 leg puller and a chassis bracket I had spare. Just drilled some holes in (roughly) the right places and put bolts through. Tightened the centre bolt until WAY tight and whacked the end of the centre bolt with a hammer. Popped off. (I don't like hitting along the crank as it loads the bearings, but the flywheel casing prevented my from hitting it with 2 hammers harmoniously.)

 

[alahol2]

Just done this on my engine. Remove the central flywheel nut. Used a small sheet of 8mm ally. Drilled 3 holes to match the 3 bolt holes in the flywheel. Placed a small ball bearing in the dip at the centre of the flywheel spindle. Placed the ally sheet over the ball bearing and inserted the 3 bolts. Gradually tightened the 3 bolts keeping the plate level until there was a loud crack. Luckily it was the flywheel coming off the spindle not one of the bolts shearing! Cheap and easy...

 

[Heckler]

Aha
I see now, lakeys pic helped, i misunderstood your description, lakeies pic and idea, superb
Stu

 

[bojin5]

Great minds think alike! I was just about to put up some information about how I made a puller from stuff hanging around the shed, but see someone has beaten me to it. The engine is all sorted now and running nicely, thanks for all the advice.

Ben