Fuji robin head leak

[tonyd]

Despite following the progressive torquing instruction in the manual I am getting problem with leakage at the cylinder head/barrel joint.
There is no headgasket so unless anyone has any ideas then my only thought is to grind the joint in with some paste as per the Vincent arrangement.
Before I do this I will try re-torquing.

Advice anyone?

Tony

[numuzmar]

maybe gasket from thin cooper foil will do the job ?

[gilburton]

Hello,I haven't done it on a Robin but grinding paste worked on a Sanglas 500.
I take it you found an engine to replace your blown one? Mines a DY41 and chugs along at 50ish.
Spares are very hard to come by or the ones available are expensive so I think if mine goes it'll be replaced by a Yanmar clone.

[XLerate]

Not to insult your intelligence or mechanical skills! but did you chase the threads in the cylinder with a tap to clean them out real good, followed by wire 'bottle brush' in threads and throughly flushing them out? Also wire brushing bolt threads too? Any lube used on bolts after that, before running them in? Did you double check the torque wrench measurements for accuracy with another wrench? Hopefully it's something simple lke that which might have been overlooked.

[tonyd]

Thank you all. I had the bike out today in the rain and it seems as if I am sorted except for a short snagging list. The nuts were free on the studs but as my engineer friend commented "are the torque settings in the manual for dry or oiled threads?" Unfortunately it doesn't say.
I took advice from Meetens who have helped with a few parts and suggested a slightly higher torque and copper grease.
My enginer friend suggested Wellseal (very high temp). I avoided the copper grease because of corrosion fears when used between Aluminium and steel. I think the main problem was not thoroughly cleaning the jointing surfaces. I warmed the engine and re-torqued once cold. So far all well.
I do have a DY41 engine which is going on Ebay sometime having purchased it believing it to be a DY42. The mounting holes are different and slightly less power and the possibility of other fitting issues.
I am must say that having stripped the engine in trying to detect the funny noises I was impressed with the modifications to the flywheel and casings and all those extra parts to tidy the engine up. It may be old diesel technology but it is well done especially using the standard primary drive.

Just a note of caution about a company called Spares Giant. I thought I might new shells for the big end and at £8.53 they seemed a fair price ( plus vat and postage)
They said they were in stock but they weren't and when I chased and chased I then discovered I had been charged £71.99. So they have gone back with a letter of complaint. Not the first time their customer service was below standard.
PS I found out that they bought the shells in for just over £20.

[tonyd]

As a sort of update to my last post. I was still unhappy about how noisy the engine was and with reduced performance too. Taking advice and internet searches I came up with Moly slip sludge remover.
Although this can be added to the fuel it works better being undiluted. I rode the bike minus the fuel tank and feeding the fuel filter with the preparation via a 500c syringe and a bit of tube. This gave me a range of 2 to 3 miles on a fill up!!!
I used the whole 500cc and the bike sounds just as it did on the old engine before it blew up.

Now the head on the new engine came off the old one and with it the injector. So at the time of the breakdown I was running with perhaps a blocked injector, the bike fully loaded and towing a trailer. I really do think that after three hours at full throttle working hard with reduced output it just could not cope. The engine manual has figures for continuous loading which are a margin below the maximum rated figure.

I do still have a head leak and once I get the Guzzi carbs sorted I will have another go with a gentle grind in.

As an aside I just had a look at recon Smart engines at around £700 they are a lot cheaper than a new Robin engine. However, I can't help liking single cylinder bikes, three cylinders seem too many!!

Tony

[gilburton]

Just sent you a pm.