Posted: Mon Aug 30, 2010 2:37pm

My Nanni 3 cylinder diesel engine has done 3500 hours and I not aware that the valve clearances have ever been adjusted. I have tried listening to the top end for tappet noise, but in a confined space with lots of other rattles around I can' be sure what I am listening to. What is your opinion on the need to adjust valve clearances, as some people say; don't bother a nb engine is never stressed. Could you also advise on the best procedure for adjusting valve clearance on 3 cylinder engine? Thank you.

Posted: Mon Aug 30, 2010 2:55pm

Hi, I also have a Nanni 3 cylinder engine. I have noticed that A R Peachment have recently started sellingNanni / Kubote workshop manuals. You will need your engine number. http://peachmentshop.co.uk/catalog/workshop-manu al-p-794.html I keep meaning to order one but forget to find the engine number ! Tony will be along soon to answer your question. Mark.

Posted: Tue Aug 31, 2010 11:48am

Thank for this information. I have bought and download a copy, I got 2 in fact because the 1st was in French and I could not read it. But I would welcome comments on my original question posted.

Posted: Tue Aug 31, 2010 7:16pm

Sorry for the delay but I have been caught up with the IWA National Boat show. This method will work for any engine once you have obtained the clearance. Turn the engine until one valve is fully open/down. Mark front pulley. Turn engine ONE complete turn. Adjust that valve and remove the mark. move onto another valve. If you are sure all the valves are rattling I doubt adjusting them will make a significant difference to the engine power. BUT if one is tight you could end up with a burnt out valve or worse. Tony Brooks

Posted: Tue Aug 31, 2010 8:59pm

Tony. Thank you for your response and method of approach. I am undecided if the valves do need adjusting. The engine starts and runs well, without any apparent lack of power. As I said earlier, at 3,500 + hours should they be checked/adjusted or should one leave well alone?

Posted: Wed Sep 01, 2010 9:50am

And as I said if the clearances are loose I doubt you will notice the difference in engine performance. If any are tight (and thus quiet) you may burn a valve or valve seat. I can not give any advice that is counter to that in your engine's manual but I have given you the information you need to make your own decision. I also have no information about the service history so it is far from clear that the clearances have not been checked in the time you state. Sorry I am unable to give you the clearcut answer you want but neither myself nor the magazine can risk you coming back and trying to claim for expensive repairs. Tony Brooks

Posted: Wed Sep 01, 2010 1:26pm

Tony. Thanks again.

Posted: Sun Sep 05, 2010 8:20am

Tony. Just an update on valve adjustment as applied to the engine in my boat. Without any reflection on you and the magazine, I could not follow your instruction for a very good reason. That reason, which I did not appreciate when posting the original question, was simply the lack of space between the front of the engine and the engine room bulkhead. I could not see the crankshaft pulley and could just get my arm down to touch it. I did manage to get a socket and ratchet bar down and managed to turn the pulley to operate the valves. I managed to adjust the valve clearances after turning over the engine a couple of times to observe the sequence of the valve movements. After each valve fully opened and closed I adjusted them. Hope this has been of some help to others Thanks again David.

Posted: Mon Sep 06, 2010 8:17am

To other readers. Please do NOT follow the above advice. It takes no account of the shape of the cams that lift the valves and as written the clearances may well now be over large because the things that open the valves may still have held the mechanism in the "not quiet closed" position. The description relates to poor boat building practise so do not compound this by poor maintenance practise. If you really can not see the edge of the crankshaft pulley then remove the starter motor and mark the flywheel. Tony Brooks

Posted: Mon Sep 06, 2010 9:56am

Tony. You make a very interesting point. Thank you David