got the head off #1 piston stuck in the bore help!

If you can keep the piston on the connecting rod without damaging the connecting rod, you may not have to split the transmission case to replace it.

newOld_kz1000 wrote:

Motor Head wrote: Interesting read. As far as your examples of pressures and related theory's, I see you left out that when running the forces are cushioned by oil pressure. Different for a Roller than a Babbitt bearing though.
All in all I would doubt that the crank would be damaged from the way you had supported the cylinder bock. With the piston stuck, but the crank not at TDC, or BDC, the forces should only serve to rotate a free spinning crank. Hopefully not imprinting the small needles from a Roller Bearing on the crank pin, or on the main bearing balls to race.

Good point -- I put 2x2" wood shims, cut down just a tad to fit, under the lifted cylinder, on the front side and on the rear, to keep it off the cases -- your characterization of my downward impact force being transferred to the rod/crank and wanting to spin them -- seems correct.

Before I started pounding to loosen the piston, I made 100% sure that the #1 connecting rod was NOT at TDC, but was forward into its downstroke of the piston, a bit away from TDC -- reason being, if the piston DID come free fast, I needed downward movement available of the connecting rod to accommodate the downward-moving piston if it came unstuck during the pounding.

I'm looking on ebay for a brand new piston -- even if I were to measure the existing formerly-stuck piston #1 and find it to be exactly dimensions as a stock piston, with the ring grooves not compressed at all -- I still would *not* re-use the #1 piston I hammered on. Not at all worth the risk and new pistons aren't too expensive.

maybe it is just wedged sideways. jammed in there really crooked or something?

donthaveakawman wrote:

newOld_kz1000 wrote:

Motor Head wrote: Interesting read. As far as your examples of pressures and related theory's, I see you left out that when running the forces are cushioned by oil pressure. Different for a Roller than a Babbitt bearing though.
All in all I would doubt that the crank would be damaged from the way you had supported the cylinder bock. With the piston stuck, but the crank not at TDC, or BDC, the forces should only serve to rotate a free spinning crank. Hopefully not imprinting the small needles from a Roller Bearing on the crank pin, or on the main bearing balls to race.

Good point -- I put 2x2" wood shims, cut down just a tad to fit, under the lifted cylinder, on the front side and on the rear, to keep it off the cases -- your characterization of my downward impact force being transferred to the rod/crank and wanting to spin them -- seems correct.

Before I started pounding to loosen the piston, I made 100% sure that the #1 connecting rod was NOT at TDC, but was forward into its downstroke of the piston, a bit away from TDC -- reason being, if the piston DID come free fast, I needed downward movement available of the connecting rod to accommodate the downward-moving piston if it came unstuck during the pounding.

I'm looking on ebay for a brand new piston -- even if I were to measure the existing formerly-stuck piston #1 and find it to be exactly dimensions as a stock piston, with the ring grooves not compressed at all -- I still would *not* re-use the #1 piston I hammered on. Not at all worth the risk and new pistons aren't too expensive.

maybe it is just wedged sideways. jammed in there really crooked or something?

Hi there donthaveakawman, we're way past that point, she's free, the piston's clean out of the #1 bore. I bought me a piston pin puller last night, all 4 pistons are coming off and the cylinder block's going out for a hone.

Inspecting the bores show ZERO pitting in the metal. The rust is surprisingly light, given the ordeal of getting that #1 piston out.


I plan to drop each piston into a gallon can of Berryman's carb cleaner overnight -- is Berryman's a good way to clean these aluminum pistons, *after* I have scraped the heavy carbon off the crown of course?

Glad to hear that, how did you manage to get it unstuck?
Remember to use assembly lube, not white lithium grease.
For a complete rebuild there is a break in period which requires roughly 500 miles with low rpm's. Keep that in mind, although this won't be a complete rebuild.

Soaking the pistons in Berrymans Carb Cleaner overnight did wonders.

Questions though:

- rings are still stuck in the grooves -- what's the safest way to get them out? I'm assuming you take a non-metalic tool and try to open up a gap at the ring's open spot -- but the rings are so tight in the grooves, there is no gap where the piston ring cut-point is
(note: I already ordered new rings, even though I have almost no experience with top end work, my gut feeling is that the fact that these rings are stuck in the grooves tells me they're not reusable, was I correct on that?)


- does $25 for a hone, per hole, sound high? And they want $105 per hole for a bore.
Can I buy a honing tool and do the hone myself?

get new rings, a ring compressor(if you can find one to fit) and for 105 a hole you are going to need larger pistons for the bore, so ask them how much to put new sleeves in there.

i charge $35.00 per hole to bore and hone,unless it is a big twin or an outboard engine.
so yes that sounds too high.

the stuck ring can be carefully cut out with an abrasive wheel,but prolly not worth your time.

your block can be bored out to the next oversize as long as it is not already 1075 cc's.

no need to re-sleeve.

hth,
leon

Soak the rings with Kroil. Ed