Honda-SOHC
SOHC.co.uk Forums => CB350/400 => Topic started by: McCabe-Thiele (Ted) on March 05, 2021, 12:10:09 PM
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Having checked my primary drive chain for wear it is definitely in need of replacement so I need to know what is the best brand for a replacement likewise with an endless camchain plus the cam chain tensioner parts?
Is it prudent to remove the pistons from the con rods (if I can) before I take off the clutch, alternator stuff etc.
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Primary chain same as 500 and elswhere is discussion on Kawasaki chain that is same but lots cheaper, dont forget damper rubbers in primary.
Camchain and tensioner bits probably Dave Silver, there is also posted on here a repair kit in stainless if the tensioner pinch bolt is fubar.
To lift the crank out the pistons need to come off
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Primary chain same as 500 and elswhere is discussion on Kawasaki chain that is same but lots cheaper, dont forget damper rubbers in primary.
Camchain and tensioner bits probably Dave Silver, there is also posted on here a repair kit in stainless if the tensioner pinch bolt is fubar.
To lift the crank out the pistons need to come off
I have found this link from a previous post.
.https://www.motorcyclespareparts.eu/en/kawasaki-parts/920571011
On the DS site the primary drive rubber is priced at £5.70 but I am assuming that there are 8 needed in total as DS does not seem to indicate you need more than one!
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23114-323-000 same as 500 and yes 8. Listed at €4each on cmsn. Worth checking your local dealer
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Sorry to ask what is obvious to many here but what's the best way to remove the circlips that hold the gudgeon pins in place they are well dinky sized?
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Lots of cloth in cranķcase holes and small screwdriver/pick under circlip at the machined groove
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Lots of cloth in cranķcase holes and small screwdriver/pick under circlip at the machined groove
Thanks for that just had a go with a small pick tool I managed to get number 4 piston outer clip out, to my surprise I was able to push out the Gudgeon Pin by hand quite easily.
One down 3 to go - a bit cold now so need a warm inside before I try another.
Took photos to ensure they go back the same way Honda markings are all on the right side of the pistons - slight score marks on the thrust side (rear of the skirt) not deep - in all probability might end up with a rebore yet just depends.
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There should be some small cast in triangles as arrows on the top of the pistons
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When splitting the cases, don’t forget the secret bolt in the sump area. No matter how long you bang, push, pull and lever, the cases won’t come apart until you remove the bolt!
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Before splitting (too late perhaps) I like to clean the outside of the engine to avoid getting grit etc into the components and interior.
Possibly of more relevance if it's a quick split, change chains etc then back together rather than absolute disassembly in total.
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Dont forget to keep the shells in proper places, if ali in one bag no way of id ing different ones
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Before splitting (too late perhaps) I like to clean the outside of the engine to avoid getting grit etc into the components and interior.
Possibly of more relevance if it's a quick split, change chains etc then back together rather than absolute disassembly in total.
Good point it's pretty clean but it can never be too clean so I will do some more before I proceed - next job will be the clutch & alternator removal. Just need some warm days to get really stuck in.
So far the engine seems to be not too bad in terms of oil grime so might not need to take everything out.
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Dont forget to keep the shells in proper places, if ali in one bag no way of id ing different ones
I will definitely do as you advise I have no shortage of plasic boxes etc that I number as I go.
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When splitting the cases, don’t forget the secret bolt in the sump area. No matter how long you bang, push, pull and lever, the cases won’t come apart until you remove the bolt!
I will look out for that thanks.
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I have safely removed all of the pistons - when I came to mark them with a cylinder number on the inside of the skirt I found that they had been done before albeit in my view back to front.
To me number 1 cylider is on the nearside (left) of the bike with number 4 cylinder on the offside (right / clutch side). There is the possibility that they were put in back to front - that might explain the poor cold compressions.
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I have safely removed all of the pistons - when I came to mark them with a cylinder number on the inside of the skirt I found that they had been done before albeit in my view back to front.
To me number 1 cylider is on the nearside (left) of the bike with number 4 cylinder on the offside (right / clutch side). There is the possibility that they were put in back to front - that might explain the poor cold compressions.
I've dismantled 2 400f engines and they were both numbered back to front like yours. I wouldn't worry about it too much. As long as the same person took them out and put them back they should be in the right place.
When I cleaned up my pistons and measured them there was too much wear in the ring slots and they had to be replaced anyway. You may find the same.
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I have safely removed all of the pistons - when I came to mark them with a cylinder number on the inside of the skirt I found that they had been done before albeit in my view back to front.
To me number 1 cylider is on the nearside (left) of the bike with number 4 cylinder on the offside (right / clutch side). There is the possibility that they were put in back to front - that might explain the poor cold compressions.
I've dismantled 2 400f engines and they were both numbered back to front like yours. I wouldn't worry about it too much. As long as the same person took them out and put them back they should be in the right place.
When I cleaned up my pistons and measured them there was too much wear in the ring slots and they had to be replaced anyway. You may find the same.
I've now decided to have a rebore as it would be daft not to now that the engine is being fully dismantled - the cold compressions were pretty poor plus there is a lip on the cylinder bores.
A case of do it once; do it right.
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Lip on the bore? You may need 2nd o/s (0.5mm) you dont often see lip on Hondas even over 100,000 mile ones
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Lip on the bore? You may need 2nd o/s (0.5mm) you dont often see lip on Hondas even over 100,000 mile ones
I'll leave that to Trigger when the block arrives tbh it was what I thought was normal at the top of the cylinder.
As I know the pistons have been out before there it might not be the original block who knows after 42 years?
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Lip on the bore? You may need 2nd o/s (0.5mm) you dont often see lip on Hondas even over 100,000 mile ones
Turns out the lip was carbon deposits - bores showed signs of previous partial seizure & freeing off probably from years of storage - having +0.25 rebore.
I have removed the external gear shift mechanism so once I have prepped the various bolts ready for removal I will seperate the halves early next week - provided it stays warmish.
I'm going to make a small wooden support frame for holding the engine casing upside down to make seperation easier. (I am a hoarder of wooden offcuts.)