Oh dear..... CT110 seized, running but not healthy
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RangaBlitzFanga
Well-Known Member
the biggest problem was bolt patterns were all wrong
All the other cylinders were also taller
All the other cylinders were also taller
headsmess
Miniriders OG
yup. wiseco 54.5mm
15mm gudgeon.
bottom of cylinder walls were like paper but pretty sure it should work. in fact, it did work, except for my lousy machining. if only id had a mill then! you cant hold a cylinder by paper thin walls but you can clamp one down on parallels and mill it...theres some carbon on top and minor scuffing. about 10mins or so run time. no rings. needs a C-clip and a wash. cheap
top of pin to edge(deck) 13mm (or 20.5 from centre of pin)
about 3.5mm crown. slightly relieved for single valves.
there should be 54mm as the base size, i think they were out of stock or summink at the time...
15mm gudgeon.
bottom of cylinder walls were like paper but pretty sure it should work. in fact, it did work, except for my lousy machining. if only id had a mill then! you cant hold a cylinder by paper thin walls but you can clamp one down on parallels and mill it...theres some carbon on top and minor scuffing. about 10mins or so run time. no rings. needs a C-clip and a wash. cheap
top of pin to edge(deck) 13mm (or 20.5 from centre of pin)
about 3.5mm crown. slightly relieved for single valves.
there should be 54mm as the base size, i think they were out of stock or summink at the time...
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RangaBlitzFanga
Well-Known Member
CRAP!
I finally got the bore done, piston here, new gaskets and all the jazzy stuff
I put the cylinder on, then I think wait a second.. Why can I rotate the camchain without it wanting to move the piston
It looks like the chain has come off the gear down in the engine. Now what do I do. I'm REALLLLLLY hoping I don't have to undo everything i've done and split the cases just to put the camchain back on?
I finally got the bore done, piston here, new gaskets and all the jazzy stuff
I put the cylinder on, then I think wait a second.. Why can I rotate the camchain without it wanting to move the piston
It looks like the chain has come off the gear down in the engine. Now what do I do. I'm REALLLLLLY hoping I don't have to undo everything i've done and split the cases just to put the camchain back on?
RangaBlitzFanga
Well-Known Member
Nevermind I managed to get it back on
Had to take the LHS cover off, no flywheel puller or holder so that option was out. After some fiddling around I realised I could drop the gear (ziptied to the chain) into the cylinder, then left the chain tensioner and turn the visible cog to the bottom left (just behind the flywheel) which fed the camchain down to the bottom of the case. Stuck a screwdriver in and pulled it all the way to the rear and up as far as it could go. After some jiggling, turning and pushing it towards the crankshaft it snagged, gave the flywheel a few turns and sure enough its on. Kept tension on oand have managed to get the head back on and timed the camchain. Just finishing off the reassembly and then i'll break it in over the weekend
Hoping it doesn't blow smoke and feels ok, as the rings are 0.40mm which is out of spec, but still serviceable. Couldn't be assed waiting on new rings after all this mucking about and they should work well enough with a whole new bore. Worst case scenario i'll get new rings and put them in, least everything else is ok
Had to take the LHS cover off, no flywheel puller or holder so that option was out. After some fiddling around I realised I could drop the gear (ziptied to the chain) into the cylinder, then left the chain tensioner and turn the visible cog to the bottom left (just behind the flywheel) which fed the camchain down to the bottom of the case. Stuck a screwdriver in and pulled it all the way to the rear and up as far as it could go. After some jiggling, turning and pushing it towards the crankshaft it snagged, gave the flywheel a few turns and sure enough its on. Kept tension on oand have managed to get the head back on and timed the camchain. Just finishing off the reassembly and then i'll break it in over the weekend
Hoping it doesn't blow smoke and feels ok, as the rings are 0.40mm which is out of spec, but still serviceable. Couldn't be assed waiting on new rings after all this mucking about and they should work well enough with a whole new bore. Worst case scenario i'll get new rings and put them in, least everything else is ok
it will blow smoke and have pretty bad compression if the rings are that far out... it will work untill you get your new rings back in..
just make sure the previous rings have no gauges or marks to damage your pretty new bore
just make sure the previous rings have no gauges or marks to damage your pretty new bore
RangaBlitzFanga
Well-Known Member
these are brand new rings and they're out. I'll get some more (these ones stamped 0.50 but I might get 1.0 and then file them down to ensure I can land within the 0.15-0.35mm spec). I'm going to break it in anyway as i'd like to get it running, I don't mind stripping and redoing the rings again now that I know what i'm doing and it should only take an hour or 2 instead of 6 like the other night
Manual states rings should be 0.15-0.35mm and 'service limit' as 0.50mm so it should at least work ok
Surely there's no problem me breaking it in and then swapping them out again soon after?
Manual states rings should be 0.15-0.35mm and 'service limit' as 0.50mm so it should at least work ok
Surely there's no problem me breaking it in and then swapping them out again soon after?
RangaBlitzFanga
Well-Known Member
ok well she's been run in. I'm leaving it for tomorrow then dumping the fresh mineral oil for another batch. After the initial ride the compression has bumped up quite a bit. Actually feels like there's a TDC now. I can hear a slight tap at anything above idle. I used new base and head gaskets, and I did check valve clearances before the ride, both at 0.05mm. Cam chain tensioner I screwed all the way in then took it out 1.5 turns
(No idea how to check it? is it supposed to go all the way in or just screw in till it stops rattling?)
edit: No smoke whatsoever, so I may leave the rings as is
(No idea how to check it? is it supposed to go all the way in or just screw in till it stops rattling?)
edit: No smoke whatsoever, so I may leave the rings as is
RangaBlitzFanga
Well-Known Member
intake valve was 0.08/0.09mm so fixed that. Also tightened camchain all the way in and no more rattle. Compression is good now, can almost stand on kick starter
RangaBlitzFanga
Well-Known Member
/sigh nope it was neither
Camchain tensioner is all the way in so it's not that
It's improved but there's still a rattle/knock sound which gets worse with more throttle
More alarming there's a scratching sound once the engine warms up a bit. The warmer it gets, the worse it is. It sounds like its coming from the head. It disappears at idle but just above that it's there. I pulled the cam cover off and it looked like the casing was rubbing against the camshaft but I can't see how to prevent it? parts fiche shows nothing behind it, just the gasket and rubber seal which is in place. It may not be that it could be something else
I'll post vids later but not today, i'm done with it for now. But if anyone has any ideas as to what the knock/rattle could likely be (i'm positive the valves are 0.05mm each) i'm all ears
Camchain tensioner is all the way in so it's not that
It's improved but there's still a rattle/knock sound which gets worse with more throttle
More alarming there's a scratching sound once the engine warms up a bit. The warmer it gets, the worse it is. It sounds like its coming from the head. It disappears at idle but just above that it's there. I pulled the cam cover off and it looked like the casing was rubbing against the camshaft but I can't see how to prevent it? parts fiche shows nothing behind it, just the gasket and rubber seal which is in place. It may not be that it could be something else
I'll post vids later but not today, i'm done with it for now. But if anyone has any ideas as to what the knock/rattle could likely be (i'm positive the valves are 0.05mm each) i'm all ears
headsmess
Miniriders OG
ahhhh, hondas... notorious for rattles after any work.
contemplating. 100 percent sure you put the right rocker and pin back into the place it came from? minor on a new engine, but after some service there could be some wear that tends to skew one way...flip it round and its now skewed the other way...causing the cam to be pushed out slightly? i dont know. just idle speculation...
you stayed with a stock piston, only overbored? its not anything fancy with a different deckheight or whatnot? by how much and have you actually measured it? you mention rings being undersized... a new set of rings supplied with the overbore piston? have you double checked the bore is the correct size?
it is a new piston right? not the old piston and rings in an overbored cylinder? if it is im just going to walk away
and you have to hone the cylinder every time you take the cylinder off. has to be freshly honed for a reason. pundits will replace rings even if they havent actually been used...
oh yeah, theyll work fine if you dont, but they wont ever get the seal that new rings get in a newly honed cylinder.
got that funky black wheel in the cam chain area of the cylinder onto its bolt? always found that bit fiddly...
i thought the camchain tension worked on a spring thats backed up by getting filled with oil that stops the plunger retracting? hence why theres always a bit of oil in there when you drop the bolt (only after having run the engine). self adjusting. can only get tighter, wont loosen unless loosened by someone. maybe im getting confused with china here...
last...didnt shave the head? checked valve stems are nice and straight? put the cam sprocket back on the right way out? (cant remember if they are flat or offset)...
contemplating. 100 percent sure you put the right rocker and pin back into the place it came from? minor on a new engine, but after some service there could be some wear that tends to skew one way...flip it round and its now skewed the other way...causing the cam to be pushed out slightly? i dont know. just idle speculation...
you stayed with a stock piston, only overbored? its not anything fancy with a different deckheight or whatnot? by how much and have you actually measured it? you mention rings being undersized... a new set of rings supplied with the overbore piston? have you double checked the bore is the correct size?
it is a new piston right? not the old piston and rings in an overbored cylinder? if it is im just going to walk away
and you have to hone the cylinder every time you take the cylinder off. has to be freshly honed for a reason. pundits will replace rings even if they havent actually been used...
oh yeah, theyll work fine if you dont, but they wont ever get the seal that new rings get in a newly honed cylinder.
got that funky black wheel in the cam chain area of the cylinder onto its bolt? always found that bit fiddly...
i thought the camchain tension worked on a spring thats backed up by getting filled with oil that stops the plunger retracting? hence why theres always a bit of oil in there when you drop the bolt (only after having run the engine). self adjusting. can only get tighter, wont loosen unless loosened by someone. maybe im getting confused with china here...
last...didnt shave the head? checked valve stems are nice and straight? put the cam sprocket back on the right way out? (cant remember if they are flat or offset)...
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RangaBlitzFanga
Well-Known Member
yes new (aftermarket) piston and rings 0.5mm oversize, cylinder was bored to the new piston. No I didn't check bore size (thats the shops job surely) nor did I check piston height. This is my first top end and no one specifically mentioned to check it so it didn't occur to me
One of the rocker pins did fall out, I put it back in, wasn't quite sure which was it came out since they look symmetrical so just slotted it back in. Could it cause a problem?
Black wheel is in
You are correct on the tensioner I believe, going off a video that was posted on the previous page (don't think it was that one, it was part #2)
Didn't shave the head, didn't remove the valves as I have no spring compressor, couldn't see well enough to measure them. Did fill the head with WD40 upside down, takes a long time (over 5 minutes) for fluid to drip through the intake (none on the exhaust) so i'd presume it to be fine
The only somewhat obvious thing is there was A LOT of carbon buildup on the original piston and the valves. I don't know whats normal but it looks like a lot to me. I don't suppose its very likely the carbon is making the valve a bit longer and touching the piston?
edit: actually i'm looking at the old piston now, there's a load of crud on the top of it, i noticed the exhaust valve pocket is speckled with carbon, but the intake one is mostly free of carbon, just black. But there's a very tiny nick (silver) on the corner of the pocket. Maybe the intake valve has stretched a tiny bit? would it be a good idea to loosen the intake valve to ~0.08mm and see if it goes away?
One of the rocker pins did fall out, I put it back in, wasn't quite sure which was it came out since they look symmetrical so just slotted it back in. Could it cause a problem?
Black wheel is in
You are correct on the tensioner I believe, going off a video that was posted on the previous page (don't think it was that one, it was part #2)
Didn't shave the head, didn't remove the valves as I have no spring compressor, couldn't see well enough to measure them. Did fill the head with WD40 upside down, takes a long time (over 5 minutes) for fluid to drip through the intake (none on the exhaust) so i'd presume it to be fine
The only somewhat obvious thing is there was A LOT of carbon buildup on the original piston and the valves. I don't know whats normal but it looks like a lot to me. I don't suppose its very likely the carbon is making the valve a bit longer and touching the piston?
edit: actually i'm looking at the old piston now, there's a load of crud on the top of it, i noticed the exhaust valve pocket is speckled with carbon, but the intake one is mostly free of carbon, just black. But there's a very tiny nick (silver) on the corner of the pocket. Maybe the intake valve has stretched a tiny bit? would it be a good idea to loosen the intake valve to ~0.08mm and see if it goes away?
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how many k's has this bike done? if its heaps i would probably just replace the valves with some good stainless valves (its pretty cheap and easy) the valve springs are a bit of a prick to put back on but are certainly worth doing
RangaBlitzFanga
Well-Known Member
about 35,000 so no not a lot really
headsmess
Miniriders OG
aupost gets rid of em at 25 usually. i clocked mine over three times without ever touching the internals. was when i swapped for a 12v system with another engine that i got sick of them.
hmmm. thinking touches of silver on piston could be it...valve hit piston, valve stems bent. if the inlet is leaking in any way at all, theres a reason for it.
id swap them valves like someone said... and the stem seals !
was the rattle there before the work or its only just started? that would be the big one.
some rocker pins have an M8 thread in one end, for pulling them out by... obviously it would face out. if its there.
be doing real well to get the cam in backwards(magic is handy!), so... cam bearings? once again, measure and double check.
it seems really strange that new rings should be below service limits. id be *****ing in someones ear about that! could be the wrong rings were supplied, who knows. but something aint right, fo sho!
cylinder should measure approx 0.1mm smaller parallel to con pin, compared to diameter at right angles to con pin... and the piston should also be ovalised by the same amount.. but will be around 0.2 to 0.3 mm under the size its meant to be... so a 53 will really measure 52.8 or so...
iunno! theres a reason why i no longer touch posties! (actually, it was the screw from the choke flap jammed the exhaust open, giving me the excuse to get the 750 going and retire the postie)
how are the rocker faces, and the cam lobes? nice n polished as they should be? or...a bit on the questionable side?
what grade fuel you running and is this new piston a higher compression than standard?
and and and, correct plug? could be kissing the piston if not.
measuring clearance between valve and adjustor, not clearance between rocker and cam? they have a certain lift ratio.
the shop had the piston when they bored it? they usually require the piston to be on hand for checking... if not, they owe you a new cylinder and dont recommend them to anyone.
hmmm. thinking touches of silver on piston could be it...valve hit piston, valve stems bent. if the inlet is leaking in any way at all, theres a reason for it.
id swap them valves like someone said... and the stem seals !
was the rattle there before the work or its only just started? that would be the big one.
some rocker pins have an M8 thread in one end, for pulling them out by... obviously it would face out. if its there.
be doing real well to get the cam in backwards(magic is handy!), so... cam bearings? once again, measure and double check.
it seems really strange that new rings should be below service limits. id be *****ing in someones ear about that! could be the wrong rings were supplied, who knows. but something aint right, fo sho!
cylinder should measure approx 0.1mm smaller parallel to con pin, compared to diameter at right angles to con pin... and the piston should also be ovalised by the same amount.. but will be around 0.2 to 0.3 mm under the size its meant to be... so a 53 will really measure 52.8 or so...
iunno! theres a reason why i no longer touch posties! (actually, it was the screw from the choke flap jammed the exhaust open, giving me the excuse to get the 750 going and retire the postie)
how are the rocker faces, and the cam lobes? nice n polished as they should be? or...a bit on the questionable side?
what grade fuel you running and is this new piston a higher compression than standard?
and and and, correct plug? could be kissing the piston if not.
measuring clearance between valve and adjustor, not clearance between rocker and cam? they have a certain lift ratio.
the shop had the piston when they bored it? they usually require the piston to be on hand for checking... if not, they owe you a new cylinder and dont recommend them to anyone.
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RangaBlitzFanga
Well-Known Member
Some very good points, and I probably should have chucked a bit more of a stink about the rings being incorrect. Shop did have the piston and bored and honed to size (0.5mm oversize, they said a 0.25 would probably work but a 0.5 is better to ensure it's perfect)
Rattle/knock was not there before the seize, however extremely rattley afterwards (piston pics posted earlier in the thread will reveal why) so difficult to tell if the valves have gone out at all. I can't pull the head to check piston clearance as that would mean a new head gasket wouldnt it?
Rocker pin has no obvious directional markings. It's got a hole right through the middle, and 1 smaller hole on each end (on opposite sides) so it looks like it should fit in either way. I'm gonna pull it out and turn it around to see if it changes anything
Here's a vid of the sound http://tinypic.com/player.php?v=f2etg&s=6 (holy hell I didn't realise my phone took such shocking video and audio quality) you can hear the knock/rattle as it accelerates. It gets worse as it heats up. Infact there's barely any knock when its cold and I wouldn't say anythings wrong. But after a couple K's of riding its really noticeable especially under acceleration.
There's also a scratchy noise which gets really bad once it fully warms up. Sounds like its coming from behind the cam cover. I actually removed the cam cover a couple days ago and I could see its edged a groove into the cam sprocket retainer. I'm going to pull it again shortly so i'll throw up a pic, but I can't for the life of me figure out why its doing that. From what I can tell there should only be a rubber seal which goes over the camshaft and into the retainer plate for the 6v stator (which doesn't exist since this is a 12v model). As well as a gasket one would assume the gasket should provide more than enough clearance so it doesn't touch the cam retainer, but it certainly looks like its been touching. Plus that seal had quite a bit of metal shavings in its groove. Have I maybe left a part out?
I'm also going to adjust the clearance to 0.08 to see if the rattle/knock goes away
edit: Yep... definately wearing a bit of a groove. That's the scratchy sound figured out
Why the heck is it occuring in the first place though?
edit2: With the retainer plate off I can push/pull the camshaft A LOT. Is it supposed to have a lot of freeplay in it? clearly that's not helping but I can't see anything in the parts fiche that would hold it more securely in place
edit3: looks like there's supposed to be a dowel pin in that little hole in the camshaft. I don't remember seeing one so its LOOONG gone if it's supposed to be there. Is that the problem? I don't see how it plays in the picture. How does a dowel pin prevent movement if it's not sitting in any grooves
Rattle/knock was not there before the seize, however extremely rattley afterwards (piston pics posted earlier in the thread will reveal why) so difficult to tell if the valves have gone out at all. I can't pull the head to check piston clearance as that would mean a new head gasket wouldnt it?
Rocker pin has no obvious directional markings. It's got a hole right through the middle, and 1 smaller hole on each end (on opposite sides) so it looks like it should fit in either way. I'm gonna pull it out and turn it around to see if it changes anything
Here's a vid of the sound http://tinypic.com/player.php?v=f2etg&s=6 (holy hell I didn't realise my phone took such shocking video and audio quality) you can hear the knock/rattle as it accelerates. It gets worse as it heats up. Infact there's barely any knock when its cold and I wouldn't say anythings wrong. But after a couple K's of riding its really noticeable especially under acceleration.
There's also a scratchy noise which gets really bad once it fully warms up. Sounds like its coming from behind the cam cover. I actually removed the cam cover a couple days ago and I could see its edged a groove into the cam sprocket retainer. I'm going to pull it again shortly so i'll throw up a pic, but I can't for the life of me figure out why its doing that. From what I can tell there should only be a rubber seal which goes over the camshaft and into the retainer plate for the 6v stator (which doesn't exist since this is a 12v model). As well as a gasket one would assume the gasket should provide more than enough clearance so it doesn't touch the cam retainer, but it certainly looks like its been touching. Plus that seal had quite a bit of metal shavings in its groove. Have I maybe left a part out?
I'm also going to adjust the clearance to 0.08 to see if the rattle/knock goes away
edit: Yep... definately wearing a bit of a groove. That's the scratchy sound figured out
Why the heck is it occuring in the first place though?
edit2: With the retainer plate off I can push/pull the camshaft A LOT. Is it supposed to have a lot of freeplay in it? clearly that's not helping but I can't see anything in the parts fiche that would hold it more securely in place
edit3: looks like there's supposed to be a dowel pin in that little hole in the camshaft. I don't remember seeing one so its LOOONG gone if it's supposed to be there. Is that the problem? I don't see how it plays in the picture. How does a dowel pin prevent movement if it's not sitting in any grooves
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RangaBlitzFanga
Well-Known Member
/sigh I can't deal with this crap
I pulled it apart last night to make sure there's nothing getting in the way of the cam or skewing it in some way. There's nothing, and it still rubs on the cam cover when it gets up to full temp
It's doing my head in, it shouldn't rub. I'm tempted to take the dremel to the casing
The knock is also still there both with clearances at 0.08 and 0.03 so I don't think its the valve. Plus it only knocks under acceleration (98 octane fuel) so i'm thinking the shop buggered the job with excessive piston to bore clearance. Which would explain why the rings were out of spec
I pulled it apart last night to make sure there's nothing getting in the way of the cam or skewing it in some way. There's nothing, and it still rubs on the cam cover when it gets up to full temp
It's doing my head in, it shouldn't rub. I'm tempted to take the dremel to the casing
The knock is also still there both with clearances at 0.08 and 0.03 so I don't think its the valve. Plus it only knocks under acceleration (98 octane fuel) so i'm thinking the shop buggered the job with excessive piston to bore clearance. Which would explain why the rings were out of spec
