B1 Cam chain adjuster

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DaveZ1
Posts: 45
Joined: 13 Jul 2020, 22:08

B1 Cam chain adjuster

Post by DaveZ1 »

Has anyone ever had the following symptoms: took my 1100 B1 out for a spin today, I’ve done about 180 miles since full refurb including the engine without any major issues and after giving it a bit of a handful on the last mile before getting home found it had developed quite a loud rattle at idle which sounded like cam chain. After switching off and having coffee started her up again and rattle had gone!! Bit worrying to say the least! I’m suspicious of the auto tensioner after doing a bit of searching and came back that they have a bad rep for failing so just wondering if anyone else has had similar symptoms of a rattle coming and going after stopping and restarting the engine.
Also I have an annoying weep on my 4 cam end plugs after the rebuild that is proving a pain to solve is there a trick I’m missing to seal them up?
Thanks for any info.
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Richard
Posts: 340
Joined: 24 Aug 2017, 14:35
Location: Zeewolde NL
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Re: B1 Cam chain adjuster

Post by Richard »

About those cam plugs, just replace them as they do become very hard after some 3o years of so.

Sorry don't have the experience with the cam chain tensioner going bad myself...
Freddy
Posts: 695
Joined: 06 Sep 2017, 11:06
Location: Sydney Australia

Re: B1 Cam chain adjuster

Post by Freddy »

DaveZ1 wrote:after giving it a bit of a handful on the last mile before getting home found it had developed quite a loud rattle at idle which sounded like cam chain. After switching off and having coffee started her up again and rattle had gone!!
Perfect description of the problems with a rachet type automatic chain adjuster. When you really crank the revs up the stress on the cam chain adjuster increases causing it to slip back and create a loose chain. At idle the loose than ideal (that's probably a better description) chain allows the camshafts to rotate in a flip/flop fashion due to the lobes and spring tensions. Rotate a fitted camshaft by hand with the head on the bench and you'll experience that effect (hard to turn as a valve is opening pushing against the valve spring, then springs forward as you pass the top of the lobe and then the spring tension does the exact opposite and tries to rotate the camshaft). That's the noise....its not the chain hitting cases which a lot of people think.

When you stopped for a while the slipped back tensioner reset itself. You could go on possibly forever like this with no serious downside other than having to tolerate that noise. Alternatively fit a manual tension (not expensive) and be done with the problem forever. I can't comment on the availability of them for the 1100. Certainly easily available for 750's.
DaveZ1
Posts: 45
Joined: 13 Jul 2020, 22:08

Re: B1 Cam chain adjuster

Post by DaveZ1 »

Thanks for that Freddy! It has put my mind at ease. I’ve found and already ordered a manual tensioner from eBay ( about £35) your description is exactly what I thought (hoped) was happening because it meant an easy fix. I’ve also ordered 4 new cam end rubber bungs from Cradley Heath to hopefully cure my annoying weep from the old ones. I thought with the bike having low mileage I would have got away with re-using the originals, but lesson learned on cutting corners I suppose but at £50 a set it was worth a try :D.
One more thing I noticed is that even though I have replaced the rings with genuine Kawasaki replacements and honed the bores ( they were very good) I noticed there’s seems to be a bit of blowing from the oil filler when opened at tick over. Could the little filter/strainer under the cover which attaches to the air box be clogged…. I didn’t check it :oops:
Thanks again Dave.
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