Topic: using an engine that has been sitting outside uncovered

[JAG]

Yikes IlBikes.. That is true determination and passion, and I'll take my hat off to that any day. Thank you, and everyone else for the encouragement, I could definitely use it!!

I love to see some before and after pics. "Sometimes it's not about the destination but the journey getting there.."  I've honestly learned more about mechanics and engines for that matter from this forum than anything else I have done..

[JAG]

broken collar

Anyone know if this is thread in or apart of the whole assembly?  Refer back to the pictures..

And do you need special tool to get the valves and rockers off and back on?

[mystic_1]

The intake flanges do thread out, but it seems they're a real pain sometimes.  See the following threads:

Intake Flange

Removing intake spigot


You won't really need a special tool for the rocker arms, the shafts should more-orless slide right out after removing the securing bolt(s),  but you'll need a valve spring compressor to remove the valves themselves from the head.  Many auto parts stores will rent such tool to you, but you don't really need to pull the valves out just yet, you can tear down the rest of the engine then pull the valves when you're ready to recondition the head.

mystic_1

[bunghole]

Intake Flange...

Just did one.  First thread in Mystic's post.

I destroyed my first try even using a torch.  I thought it was unscrewing, but it was really just shearing apart.  The second try, I used lots of heat and tried not to over torque it.  It came out OK, with a few bungled threads, but I think (hope) it will work for the head it is going into.

There is some sort of adhesive that is used, so you might try some sort of paint stripper or adhesive remover to soak in there, but it is so tight, I'm not sure anything would even be able to work its way deep enough to make a difference.

You might actually be better off trying to bust apart the broken one and remove it in pieces so that the threads on the head don't get buggered.  Then the trick will be finding a good flange to replace it with.  If I end up with any spares, I will be happy to send them to you.

[mystic_1]

You might actually be better off trying to bust apart the broken one and remove it in pieces so that the threads on the head don't get buggered.

+1 to this - I'd use a dremel to cut slots lengthwise along the inside surface of the collar stub, then break it out in pieces.

mystic_1

[JAG]

OKay this is where I am at now. I am trying to pull out the rocker arm shaft and I can't figure out how. I don't have the "rocker arm shaft remover", which to me via the diagram in the shop manual just looks like a long rod.

Any ideas on how to take it out?

I am wanting to get a view of the pistons and see what kind of condition they are in and where or not the cylinders need to be honed.

Here is a picture of what it looks like where I am at now.

I have marked and labeled and put things into their own individual baggies.

[JAG]

And as far as the flange goes, I don't think there is any way to get it out, there isn't much left showing on the outside of the head. I think I am just going to use my "head" from my other engine, since it is already freshly painted and looking good.

[JAG]

So no ideas on how to take out the rocker arm shaft??

[Hush]

Keep going, you're doing great.
Not sure about the rocker shaft remover thing, wait long enough and someone will give you the brilliant solution.

[mystic_1]

I see you've already removed the rocker shaft retaining bolts, so just back off all the tappet adjusters to relieve pressure, and the shafts will push right out the sides.  The Honda tool IS just a long rod, so you can tap the shafts towards the outside of the engine.  They should more-or-less just push out with light finger pressure, I've never needed to use a hammer as they show in the books.

mystic_1

[JAG]

Thanks again for all you guy's help!!

I finally figured how to get down to the pistons, with a lot of readin, picture viewing, and patience, because I don't wanna screw anything up!

Here are some pictures of the piston heads, just as I pulled the casing away. I haven't donw anything to this point except take the casing off, snap a few pictures, and come on here to show you guys.

I have no idea what to look for, as for the condition of everything. So is there any specifics on what I should be looking for and how to go about it?

My goal is just to make sure the piston rings and gaskets are to be replaced, I really didn't want to get into anything deeper than that, unless of course it's necessary.

Any thoughts on going deeper into things at this point?
Any thoughts on the specifics of the pistons and how they should look?

My main goal again is to have this one in tip top shape, before the other one poops out on me..

[JAG]

It seems like there is a lot of rust/dirt and grime on top of the piston heads. and the rim/top edge of the cylinder walls, going into about 1/8" down into the cylinder is rough, but the cylinder walls themselves are very very smooth to the touch.

[scondon]

   All the stuff you poured down into the combustion chamber, and consequently all over your garage(thanks again for that mental picture ), has most likely collected all the gunk from the rings and above and concentrated it in the top 1/8" of the cylinder.

    Since your already stripped down this far the next step would be to remove the cylinder block and clean it. You can then get a good look at the piston sides and rings to inspect for wear and rust. Really you just want to strip everything, including pistons/rings, and give a good cleaning up before inspecting.

    Your cylinders look pretty decent considering

[JAG]

Ok great. Thanks... The shot across the garage still haunts me, but it made me believe it had good compression!!

I'll take it on down a bit further then and see what it looks like..

[JAG]

I cannot figure out how to pull off the crankcase from the cylinder. It says there is 5 6mm bolts as stated in the shop manual but I don't see those anywhere.

[Hush]

Yeah you are this far and all it is gonna cost you to rebuild at this stage is a gasket set.

[Hush]

Not owning this model I'm not sure, check around the base of the cylinders, sometimes Honda bolt the cylinders down with short bolts.

[scondon]

I cannot figure out how to pull off the crankcase from the cylinder. It says there is 5 6mm bolts as stated in the shop manual but I don't see those anywhere.

    Once the cylinder head has been removed there are no more bolts remaining that hold the cylinder to the engine. Theoretically it should lift straight off. The base gasket and the two locating dowels at the bottom of the cylinder can hold on for dear life so it is not always a simple matter of breaking it loose.     

   There is a casting at the bottom front of the cylinders that reads "736cc". I place a piece of wood against the bottom lip of this and give a few whacks, then wrestle, twist the cylinder, then a few more whacks, etc... until the base gasket and dowels release their death grip.

[mystic_1]

OK, I just thought this up, never done it this way, and it may be a bad idea, so take it with a grain of salt.


Clean out the cylinders above the pistons really well, rotate so that the 1 and 4 pistons are at BDC, then stuff rags or rope into the cylinders.  Now, reinstall the head but only put in the four short bolts that connect the head to the cylinder block.  Now rotate the engine using the crank nut, pressure from the pistons should push up on the head which will pull the cylinder off of the base gasket.


mystic_1

[Hush]

nah mate go with Scodon's idea, it's pretty std for these thing to think they are welded together.

[JAG]

I cannot figure out how to pull off the crankcase from the cylinder. It says there is 5 6mm bolts as stated in the shop manual but I don't see those anywhere.

    Once the cylinder head has been removed there are no more bolts remaining that hold the cylinder to the engine. Theoretically it should lift straight off. The base gasket and the two locating dowels at the bottom of the cylinder can hold on for dear life so it is not always a simple matter of breaking it loose.     

   There is a casting at the bottom front of the cylinders that reads "736cc". I place a piece of wood against the bottom lip of this and give a few whacks, then wrestle, twist the cylinder, then a few more whacks, etc... until the base gasket and dowels release their death grip.

Well that worked like a charm. I used a long crow bar instead, right on the 736cc and at the same spot on the opposite side, and it inched it's way up. Although I chipped a piece of fin off, because it jumped off the "736cc", but it's okay..

The pistons looked like they were in pretty good shape. All the rings except two moved, but they'll all be replaced anyways.

A question I do have is about honing the cylinder walls. The cylinders walls are pristine except the top 1/8 inch. So if/when I do go about honing the walls, is it possible to OVER hone the walls and actually go to far in concerns to diameter? The way I've heard it done is by using it on the end of a drill, but that to me seems like there is to many things that could go wrong with that. Anyone have any experience doing the honing themselves?

Next question, is when I go to replace the cylinder back over the pistons with the new rings, is there a compression tool to compress the rings while the pistons slide back through the cylinder wall? I would think it would be near impossible to get the pistons back through without taking them off at the crank and feeding them through manually, and maybe being able to attach them back once the cylinder is back on. Am I way off here?

Also is there a way to recondition the piston heads? They don't look bad, just the usual carbon deposit that I think should be on there.

Thanks for all the help. I need to do some research and find out how much the rings are..

Anything else you guys think I should do besides honing and rings?

Thanks again guys! I couldn't resurrect this poor engine from certain doom without you guy's help!

JAG

[scondon]

   Since the piston rings don't actually go all the way to the top of the cylinder block a 3/16" ring of carbon deposits can form around the top of each cylinder. It is rough and nasty to the touch and completely normal in an old engine, in my opinion. I'm sure the ring around your cylinders is covered in rusty goo at the moment but a scotch-brite pad and a little muscle oughta do wonders.

    Wish I had taken pics of what my "left out over Winter" engine looked like. Yours looks pretty nice in comparison and may well prove to be an easy rebuild

[JAG]

    It is rough and nasty to the touch and completely normal in an old engine, in my opinion. I'm sure the ring around your cylinders is covered in rusty goo at the moment but a scotch-brite pad and a little muscle oughta do wonders.

So in your opinion, since the piston  heads and cylinder walls are nice and smooth, I should just go at it with a scotch-brite pad and not worry about honing, or polishing the walls?

    Wish I had taken pics of what my "left out over Winter" engine looked like. Yours looks pretty nice in comparison and may well prove to be an easy rebuild

I would love to see those pictures!!

I have a few machinist buddies, that may do the honing for me fairly cheap, I just don't think I could do accurate job on my own. So with that said, if it is within reason and cheap I may go ahead and let them do it, but if it isn't and you don't think I need to get it done anyways, I'll just not worry about it..

Also, is it that difficult to get the pistons back in the cylinder once new rings are placed? Is there a special tool or a way to go about getting them back in??

[chrislib]

If all your going to do is break the glaze on the cyl walls a ball hone works best/has less of a chance of removing too much material. With a rigid 3 stone hone it`s easier to "get carried away" and open up the clearances.http://mgaguru.com/mgtech/tools/ts312.htm

[Gordon]

When you replace the rings you need to hone the cylinders.  You don't need a ring compressor to get them back in.  In fact they really just get in the way.  Your fingernails and gravity are the best tools for that job.  Raise the middle two pistons, get them in the cylinders, then turn the crankshaft to bring the outer two pistons up and slide them in.