Stihl 064 with 066BB, along with a complete rebuild of the bottom end

epicklein22 · Feb 8, 2009

First off, I would like to thank Lakeside for the great pictures, details in this thread on splitting cases and reassembly, http://arboristsite.com/showthread.php?t=40590&highlight=066+splitting+case. Secondly, I would like to thank Jacob J for the help his has given me so far and in the future on the 064 with a 066 big bore kit. He has done this set up numerous times and has the insight of what is needed to make it work.

While I am not as fast as Brad, I will try to post the same amount of pictures. :clap:

So this thread will be a little slow and I will update as I go along.

So first off is splitting the 064 case and pressing out the bearings. With the help of the fore mentioned thread and my dad's experience of doing bottom ends on old 2-stroke dirtbikes, My dad and I plunged into the 064.

The reason for the splitting of the case was due to a bad pto bearing. The polymer retainer let go.

Now to the pictures:

PTO side, splitting the case. Went surprisingly easy.

PTO side bearing shell. The ball bearings are held in by a plastic/polymer retainer and it had let go. The whole thing just fell apart when touching it,

Here is how we knocked the crank out. We set it up on the wood blocks, with the crank free of restriction and gave it about 3 medium taps with a dead blow hammer. Didn't take much at all. Very simple.

The prize:

stihlboy · Feb 8, 2009

the first bb kit i got that was messed up had the same green tint to it the new one is black

blsnelling · Feb 8, 2009

Way to go. You know we like the pics

Do you have your BB kit yet? How's the combustion chamber and squish band look?

epicklein22 · Feb 8, 2009

Continued:

Pushing out the flywheel bearing. I didn't care about the seal, so a properly sized socket and the vise and it popped right out.

PTO bearing. Not enough recess for the bearing to push all the way out, so my dad and I cut some wood blocks for extra space.

epicklein22 · Feb 8, 2009

Up next, a lot of cleaning and then I need to grind on the case for the BB piston to fit. I have a bucking spike hole that is broken, so I am gonna fix that too. Then tomorrow, I am gonna pick up a 6mm x 1 tap and redo the case bolt holes.

epicklein22 · Feb 8, 2009

blsnelling said:
Way to go. You know we like the pics Do you have your BB kit yet? How's the combustion chamber and squish band look?

I am gonna go eat and then I will post a few pics of the BB kit.

epicklein22 · Feb 8, 2009

A couple BB pictures I shoot real quick when doing the case:

The exhaust port has tons of casting flash. I plan to knock that down and then polish it up really good.

Squish area. Tell me if it looks bad guys. I don't quite know what to look for.

excess650 · Feb 8, 2009

I dunno if its reflection in the photo or not, but the top edge of the squish band doesn't look quite right. Just to clarify....

Does the shiny, machined surface go all the way to to the cylinder bore?

Does it appear pretty even all the way around?

If yes to both, its good to go!

blsnelling · Feb 8, 2009

Your cylinder has the same casting problems I'm seeing on all recent 066BBs. Look at all the "sand" finish in the combustion chamber. The squish land goes right into the chamber with a sharp edge and not rounded. Also, there's little to no actual land around the outer perimeter. It's nearly flat all the way from the cylinder wall to the dome. Make sure you check your squish before firing it up. The last one I did varied from .016 to .011 with a gasket. The line that you see right down the middle of the head is an actual crack. It is not a ridge. Look at the roof of the exhaust port. It is 100% flat. Scary stuff for a 2-stroke engine builder. I really want to like these kits, but there are several serious problems with them right now. Rumor has it that a new smaller combustion chamber and a raised exhaust port floor is in the makes. That can't come soon enough. I'm not here to sling mud, but won't hide the truth either. I'll be the first to praise them when the fixes come.

excess650 · Feb 8, 2009

Brad,
I just took another look at the Mahle cylinder on my dining room table.

The squish band doesn't look any different than that in that BB cylinder, provided that the machined part on the BB goes out to the bore(mine does). As for the transition from the squish to the combustion chamber, its almost flat until the edge of the clearly defined dome. The biggest difference that I can see in that part of the cylinder is that the BB definitely has a rougher combustion chamber, and the parting lines are evident.

I did think it odd that despite having a larger bore, the BB cylinder has smaller ports. I would have expected them to be the same size, or slightly larger than OEM.

epicklein22 · Feb 8, 2009

blsnelling said:
Your cylinder has the same casting problems I'm seeing on all recent 066BBs. Look at all the "sand" finish in the combustion chamber. The squish land goes right into the chamber with a sharp edge and not rounded. Also, there's little to no actual land around the outer perimeter. It's nearly flat all the way from the cylinder wall to the dome. Make sure you check your squish before firing it up. The last one I did varied from .016 to .011 with a gasket. The line that you see right down the middle of the head is an actual crack. It is not a ridge. Look at the roof of the exhaust port. It is 100% flat. Scary stuff for a 2-stroke engine builder. I really want to like these kits, but there are several serious problems with them right now. Rumor has it that a new smaller combustion chamber and a raised exhaust port floor is in the makes. That can't come soon enough. I'm not here to sling mud, but won't hide the truth either. I'll be the first to praise them when the fixes come.

Hmm, not what I want to hear, but I need to hear it. I will take a good look at it and see if it is acceptable before grinding on it. While the nikisil looks good, the rest is less than desirable, but what can you ask for a third of the price of OEM? While I don't know squat about ports, the exhaust sure does look really squarish. I have a 066 slug and jug if need be........

epicklein22 · Feb 8, 2009

blsnelling said:
The line that you see right down the middle of the head is an actual crack. .

How is that a crack? Wouldn't that make this kit junk?

stihlboy · Feb 8, 2009

epicklein22 said:
How is that a crack? Wouldn't that make this kit junk?

well you said it not me!!! i understand these cylinders can't be perfect, but i'd like to see a little improvement. BTW baileys customer service is second to none they have a customer for life!

blsnelling · Feb 9, 2009

Just make sure to check the squish on all four corners. The one I put on Stihlboys 066 was .016 on three sides but only .011 on the other. That renders that cylinder unuseable. Baileys did replace it, but the new one doesn't look much better. We'll just have to bolt it up and see.

Lakeside53 · Feb 9, 2009

stihlboy said:
well you said it not me!!! i understand these cylinders can't be perfect, but i'd like to see a little improvement. BTW baileys customer service is second to none they have a customer for life!

I disagree. They can be "perfect"... at least in the sense of "fit for function", but it's just easier to hand another to the guys that complain than to fix the problems. This latest issue with squish is QA 101... Obviously nobody in China checks, or if they do have a very slack spec. Selling junk and smoothing the waters with "customer service" is the wrong approach - why..that's just like Harbor Fright....

opcorn:

BobL · Feb 9, 2009

epicklein22, your jug

looks like it has the exact same comb chamber marks as my first kit

Brad, back in your 066 BB thread you called the chamber marks a casting line - are you now claiming it's a crack?

I finally got my free replacement BB kit from Baileys last week (I had another part on backorder that held up the order - decided to wait cos shipping costs to Oz are not cheap). New kit looks different, firstly cosmetic changes, cylinder and part of lower inner piston are black and there are significantly fewer comb chamber marks - I'm at work right now - will post a pic when I get home if anyone is interested

I've made a pressure testing rig using bits and pieces from the lab but haven't had time to do anything with it because I'm distracted by mucking about with the 880.

blsnelling · Feb 9, 2009

Crack was probably not the best choice of words. It is the line from what appears to be halves of a mold, but that line is actually a "crevice" in the combustion chamber.

Tzed250 · Feb 9, 2009

Looks to me like the de-comp fitting is way to far into the cylinder. Lake is right, if this is an example of the QA at that plant it says a lot to the fact that this stuff is not ready for prime time. Casting flaws, slack machining tolerances, rings that hang in the ports, heavy wristpins, sketchy circlips, etc. The squish thing is poor. It is bone simple to hold .005" in a machining operatation. Set the spec at .025 +.003/-.002, not that hard. I could see maybe trying to make one these things work on a beater that is on its last legs, but there is no way on this green earth that I would install this stuff on my 660, especially as a "hop-up"!

blsnelling · Feb 9, 2009

Tzed250 said:
Looks to me like the de-comp fitting is way to far into the cylinder.

The plug I put in Stihlkid's stuck through like that too. Perhaps the head isn't as thick as stock.

Tzed250 · Feb 9, 2009

blsnelling said:
The plug I put in Stihlkid's stuck through like that too. Perhaps the head isn't as thick as stock.

Do you have a Mahle and a Baileys you can measure?

Stihl 064 with 066BB, along with a complete rebuild of the bottom end

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