71 fastwin 18 top crank seal

[kolo66]

Hello all

I've been lurking around and reading for a while now. but this is my first post.

I have had this motor about ten years. great little motor. anyway, a few years back it started to have a few problems, so I started to do a tune up. Coils, point, etc... In the process I found out that the seal under the coils and points (not sure of the name) was bad. Now remember this was several years ago (6 I think) but somehow I removed the old one and put in a new one. I got it all back together and took it out a couple of times and all was fine.
I thought so anyway. I've been working on this for a few days now and could use a little help. To make a long story short, That seal is bad again. There is oil all over my coils and points. Not sure if there is a small bur on the shaft or I didnt get the seal in right or what?
How do I get the seal out? Hopefully without breaking the motor down.

suggestions please

 

[1946Zephyr]

Re: 71 fastwin 18 top crank seal

You should be able to remove that seal without any problem. Just be careful about prying it out without marring up anything around the top of the engine block.

 

[kolo66]

Re: 71 fastwin 18 top crank seal

I've tried just about everything and I cant get the seal out. I'm about ready to split it in half.
How bad of a job is that? At least I would be able to really clean and inspect the area good.

 

[1946Zephyr]

Re: 71 fastwin 18 top crank seal

well, you would have to of course pull the powerhead and then split the block. Checking things out further wouldn't be a bad idea either.

 

[Mas]

Re: 71 fastwin 18 top crank seal

Can you drill into the seal a little bit and get a screwdriver into it? If so, you can set up a little fulcrum and pry it out as to not damage any of the the surrounding metal.

Seals can be a real pain. I just spent about 2 hours removing the pinion shaft seal from my lower unit on my Honda...and that was with the shaft removed! I finally got it out by digging into it and prying it out with a fulcrum and screwdriver. I have a seal/bearing remover...but it was too big to get in...bummer! But, I did not let it beat me.

MAS

 

[kolo66]

Re: 71 fastwin 18 top crank seal

Hey

Thanks for the replies.

I ended up removing the power head and splitting it in half. I found out why the seal went out again, The upper roller bearing is bad.
I just got through going into the parts manual and getting the numbers of the parts I think I need to fix this.

Roller bearing #0377528

Seal #0305987

o-ring #0302537 Big o-ring top and bottom of crank bearings



Manifold gasket #0315991
These are the only 2 gaskets I removed in the power head
Gasket plate to c-case #0316540



Exhast gasket #0314421


A question I have is what is used for a seal at the main case where the crank shaft is. There was no gasket just a really small bead of some sealant?

Does the parts list above sound about right?

Before I started this, I checked the compression and got 120 psi both cylinders at 5 pulls each. Changed the coils and points. Rebuilt the carb and the fuel pump.

This is a low hour motor for a 71. I am just wanting to do a good job and get it right. I would appreciate any opinions

thank you

 

[kolo66]

Re: 71 fastwin 18 top crank seal

Well I should have looked around a little more before my last post. My manual answered my question about sealing the case (seal 1000) and for the gaskets and bolts (perfect seal #4). There seems to be a lot of different info on what alternatives there are for these. Here is a post from another thread.

From auto store trip I am using VersaChem 'Prime Seal Gasket Sealant type 3 aviation' in place of Sealer 1000 and Permatex 'High Temperature Thread Sealant' for the Perfect Seal #4. Both of these seem to fulfill the requirements, though the 'High Temperature' is not necessary it does protect against corrosion and provides some resistance to vibrating loose.


Is this ok, or are there better choices

Thank you

 

[R.Johnson]

Re: 71 fastwin 18 top crank seal

If the upper bearing is bad, what does the crankshaft look like?

 

[halmc]

Re: 71 fastwin 18 top crank seal

As a sealer, Yamabond can't be beat, available at any Yamaha motorcycle shop.

 

[kolo66]

Re: 71 fastwin 18 top crank seal

The crankshaft seams perfect. I couldnt tell the bearing was bad until the powerhead was apart. all of the rods were in place but the thing that keeps them spread out evenly is gone. Must have been some sort of plastic like the middle crankshaft bearing. I cant tell from looking at the lower shaft bearing, but I can see that the rods in it are spaced evenly.

 

[R.Johnson]

Re: 71 fastwin 18 top crank seal

There should be a recirculation oil line running from the bottom bearing to the top. Make sure this is place, and not cracked, or broken.