Jump to content

Bsa C15 Timing Side Bush Tight


sickswan
 Share

Recommended Posts

so I have built my c15 almost completely from jumble parts and its time to get her running however there is a problem.. the timing side bush I have turned up is slightly tight I really don't want to strip it back down an if I do I will prob just buy the bearing conversion.. however any one else had this problem when using a bush for timing side? it is very hard to kick over altho not impossible.. doesn't help that im using an m20 kickstart borrowed from a friend.. any ideas on how to loosen her and get the oil pumping round to loosen it up a bit??? any comments welcome

Link to comment
Share on other sites

 

 

Why not try starting it and then running it . If you can run it for a few minutes then let it cool down. Keep doing this for a few times and it may be ok. If you are thinking of rebuilding it anyway you have nothing to lose.

Link to comment
Share on other sites

 
 

Also I have my pvl set to fire at 6.5mm before top dead centre it's a sammy miller pvl however the destructions are very vague they say to set it 5 to 8 mm from tac anyone any info on a narrower range???

Link to comment
Share on other sites

 
 

just get a couple of mates to give you push then once running you can set i tto a fast tickover to let it bed in , i have found that some of the bushes are a tad to thick leaving you with no end play and a tight engine the real answer is to pull it apart shorten the bush a bit then shim the crank to give the correct clearance , i would give it about 10 thou with the cases tightened,will

Link to comment
Share on other sites

 

Hi Guy's,

Hi SS,

Or should this be SOS,

STOP,

Pull the motor apart and do the job properly !

If It is tight it is never going to be any good!

Have you got a puller to pull the crank firmly into the drive side bearing for a start?

And if you have made up a bearing for the timing side what is it made of? and is it line bored?

You should when the crank is in the cases before the build, be able to spin the crank over freely with thumb and finger using the conrod, if you can't do this there is something wrong.

If you fit a Alpha needle bearing conversion, this needs great care in fitting too, and the same applies.

Please please don't treat this motor like a lump of steel and alloy, get it right, these are getting short in supply now, and need treating with respect.

You know who I am? so just take a look at the web site.

Regards Charlie.

  • Like 1
Link to comment
Share on other sites

 

thanks guys guna have to be stripped then.. nemind something to do over the weekend! yes pulled in and bush is phosphor bronze. line bored? never heard this term? I made it as a replacement to fit in original outer piece..

  • Like 1
Link to comment
Share on other sites

 

I would recommend fitting the Alpha timing side conversion.

As Charlie says, the crank should spin freely in the cases, if it doesn`t, then there is something wrong. Mine wouldn`t spin freely because the bigend hole in the conrod had a very slight oval in it. It was fine with the old bearing but the new one was tight. Alpha honed it for me and all was well.

Don`t run the engine unless you have oil circulating through out the engine first. The oil pump won`t prime the system on its own, I used a pump oil can to force oil through the feed pipe, once running, make sure the oil is returning to the tank before you ride it.

I don`t want to sound like I`m trying to tell granny how to suck eggs but I learned these lessons the hard way. I would save you the time, expense and heartache of lunching a freshly rebuilt engine.

Link to comment
Share on other sites

 
 

Cheers boys ripped it down in a few hours tonight Turns out aawil hit the nail on the head crank spins fine until the cases are bolted that last half mm shut.. Guna press out the bush and outer bit tomo an skim up on me lathe hopefully should sort it.. there's a timing side conversion on ebay at min 132.50 but he can't post it until 14th an i wanted to have it running by then as I'm going for back op on 21st so will be out of action for 3 months at least :( fingers crossed that will sort it... watch this space.. also to the otter bloke I've found out what line boring is a friend told me. Seems like a ball ache but I guess it's the only way to get it right if crank cases arn't matched.. I turned my bush in the outer if that makes sense lol well I roughed it out then pressed it in and skimmed it up to finish. cheers luke

Link to comment
Share on other sites

 

Oh yeah my big end is new I turned it from a bearing race bloody hard stuff to turn.. got thro a few carbide tips but did the trick. Should have used cbn (carbide boRon nitride) tips but we don't stock many at work for the tools I have at home.. also got 1/4 x 1/2 inch rollers in there first time I pressed crank together rod wound it's self from one side to other so had to pull that apart and skim out the few microns taper in it as the 1/2 long rollers were exaggerating the taper might have been alright with 1/4 x 1/4 rollers oh well all sorted now

Link to comment
Share on other sites

 
 
 

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

×
  • Create New...