found problem why timer base was sticking

[rsimmons42]

I found the problem as to why my timer base was sticking, the upper roller bearing was high causing a fource on the timing base and causing it to bind. I have a picture attached. I have banged it back in place with a piece of wood. Now what would cause the roller bearing to be high, and how can I keep it from happening again?

 

[R.Johnson]

Re: found problem why timer base was sticking

Is there a hole in the bearing shell? This fits to a retaining pin in the block to lock the bearing in place.

 

[rsimmons42]

Re: found problem why timer base was sticking

when you say hole, do you mean on the top of the upper main bearing, My motor is a 1977 70 hp model 70EL77S.

Thanks

 

[rsimmons42]

Re: found problem why timer base was sticking

just went and looked at it and No there is not any hole at any location. But having said that, there are two nuts on the top of the housing that I was able to tighten about 1/2 to 3/4 of a turn.

 

[rsimmons42]

Re: found problem why timer base was sticking

I have circled one of the nuts in this photo.

 

[rsimmons42]

Re: found problem why timer base was sticking

anybody have any input as to what holds this in place?

 

[R.Johnson]

Re: found problem why timer base was sticking

I checked my OMC service manual, the top, and two center main bearings' are secured in the block by dowel pins. It can be very hard to tell without the engine right in front of you, but that top main bearing looks alright. Don't beat on it . If that bearing is secured on it's dowel pin, I don't see how you could move it. I think your problem is else where.

 

[jonesg]

Re: found problem why timer base was sticking

I'm guessing but those nuts you tightened,

they look like pinch bolts, maybe they are the dowels R.Johnson mentioned, they could be tapered steel dowels, the nut being used to draw them tight.

 

[rsimmons42]

Re: found problem why timer base was sticking

I checked my OMC service manual, the top, and two center main bearings' are secured in the block by dowel pins. It can be very hard to tell without the engine right in front of you, but that top main bearing looks alright. Don't beat on it . If that bearing is secured on it's dowel pin, I don't see how you could move it. I think your problem is else where.

when you say else where, where else could that be. When I look at the break down in the manual, it does not show any dowel pins. the bearing looks to be in great shape. the break down does show a hole in the casing of the bearing, but does not have a dowel in the parts list. But this bearing is used on about 25 different models.

 

[rsimmons42]

Re: found problem why timer base was sticking

Will I be able to lift this bearing out to take a closer look?

 

[R.Johnson]

Re: found problem why timer base was sticking

You can not see the dowel pins, they are inside the crankcase casting, same with the dowel pin hole in the bearing, The bolt you have circled, this is the top crankcase stud, with washer, and nut. It is also the retainer for the top main bearing, and must be torgued properly. Where else could be your binding problem? Stator plate bearing dry, dry control arm bearing. Disconnect the linkage to ignition stator, and see how it turns. Do you have a proper service manual for this engine?

 

[rsimmons42]

Re: found problem why timer base was sticking

yes I have a service manual for this engine and it says that the upper main bearing just slips off, and same with reinstallation, says nothing of the dowel. The mids are with a ring and same with the lower. I torqued the studs correctly and got out a pair of channel lock pliers with a cloth of cource and checked to see if it would move, it appears to be rock sollid. when I taped it back down it moved down about .100. But this was enough to cause the problems with my timer base binding.

 

[R.Johnson]

Re: found problem why timer base was sticking

I'll pass this off to someone else. I'am at a loss.