Short cam chain

denisducati750

650 Custom Chop
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Guys I'm putting my top end back together as a 62 year young first time rebuilder. Have a new cam chain but it is a link too short for me to throw the joiner link in. I've turned the a.lt anti clockwise to take up front slack to no avail. The two front adjuster screws ( the big ones) seem to sit about 5mm or a quarter inch into the engine, and this seems to push the front cam chain guide in too far - so I've loosened them off enough to have them sitting about flush - but still too short. I've got the old cam chain but if I run that back in to compare measurement with the new one, I still don't know how long the cam chain is meant to be - when new. Any help or suggestions appreciated. Slug. :doh
 
Posting this brought up 'similar issues' - I reckon I must have a kink or its riding on the bottom sprocket teeth instead of running true in the grooves. This sure is a great site. Have way exceeded my internet download watching Nightflyer rebuild his XS on You Tube! Great help! Thanks, Slug.
 
... Have a new cam chain but it is a link too short for me to throw the joiner link in. I've turned the a.lt anti clockwise to take up front slack to no avail.

1974 was supposedly the first year to changeover to "447" type engine components, including crank/cam sprockets and camchain. You want your new camchain to match the link pitch of the original camchain. Might be a mixup there.

full


Also, be sure that your rear camchain adjuster is not installed.

... The two front adjuster screws ( the big ones) seem to sit about 5mm or a quarter inch into the engine, and this seems to push the front cam chain guide in too far...

Now, there's a problem. Those aren't adjusters, just barrel bolts for the front guide bolts. Shouldn't be protruding into the camchain tunnel...
 
Well I reckon you might be spot on. It is actually closer to 'half a tooth' off in terms of length. I removed the oil tray and looked up through the bottom end - the new chain is not kinked or sitting on sprocket teeth instead of in grooves, plus I counted the teeth on the cam and it was spot on for the manual at 36 teeth. I'll call the bloke I bought the new cam chain from on Monday and see what he thinks based on what you've offered. Really appreciate your thoughts as I really was running out of options.
:thumbsup:
 
The new cam chains tend to be very tight due to the links being grease packed from the factory. I just installed mine by slipping the cam bearings off of 1 end, attaching the master link and then re-installing the cam bearings.
 
Yeah, new chains are REALLY tight. Just take one set of bearings off the cam. Or all the bearings off the cam until the chain is on. One bearing on each end to check the timing. Make sure the cam tensioner os off but the tensioner wheel is installed.
 
So revisiting this thread I noticed that Boats.net has the cam chain listed as 94500-02106 but the link is listed as 94662-19001, which appears to be incorrect according to the page listed above. And is advised against interchanging them.
Partzilla also has the same listing.
Last time I bought a chain it came with a link and I bought the correct 94600-02001 as a spare.
So, would this cause a problem interchanging them?
 
Yes, it is rather confusing. The link you need depends on the chain brand you have. At one time, Yamaha sold both the D.I.D. and Tsubaki brands, along with their master links. Now I see they have discontinued the D.I.D. chain but still list it's master link. The "19001" is the D.I.D. link for the "FT219" type D.I.D. chain .....

http://www.boats.net/parts/detail/yamaha/Y-94662-19001-00.html

I don't know if it would work on a Tsubaki chain but I don't think I'd risk a possible major problem (chain coming apart) over a $4 part.
 
Thanks. I ordered a chain today and hope it still comes with a link. I also ordered the correct 02001 link in case it doesn't ( I can't locate the spare I bought before)
 
Just a piece of trivia to add here.

256 camchain = 102 links x 8mm (0.315") pitch = 816mm (32.126") total length

447 camchain = 106 links x 7.774mm (0.3061") pitch = 824mm (32.447") total length

Not only do you have to be mindful of the master link's pin spacing, I've heard that there's also a slight difference in pin diameters. One combo won't fit, the other too loose.

Even though the 447 has a shorter pitch, the increased toothcounts of the 447 sprockets will take up the additional camchain length...
 
Really useful. Thank you. now to find a 256 Cam chain. without paying loads of tax, Cant get anything from Europe (Brexit) dont want to get from the states postage and taxes make it expensive. Try Japan, see how I get on there.
 
One thing some of us do is to use large nuts and or washers or sockets as spacers. Place these over the studs. Must come up to cover part of the threads. Put on the stock nuts and snug down. This compresses the head, cylinder and base gaskets a bit. Don't exceed more than 1/2 the required torque.
This often is enough to assemble the chain.
Removing the bearing on one end of crank works too.
Leo
 
Cant get anything from Europe (Brexit) dont want to get from the states postage and taxes make it expensive. Try Japan, see how I get on there.

Not sure why Brexit would preclude the EU particularly now an agreement has been reached.
Provided the chain is less than £135 there would be no import duty; only VAT would be payable regardless of where the part is sourced outside of the EU.
The only variable would be postage.
 
Hi Max, I wrote this pre, brexit deal, Additionally Heiden tuning are not exporting to the Uk. Also Yambits dont have any stock for a 256, if you know of any stock in the UK. please let me know.

thanks
 
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