Replacing the cam chain tensioner arm is totally unnecessary. Contrary to popular opinion, there is nothing at all wrong with the design/manufacture of the original tensioner arm. Firstly, the only reason it gets damaged in the first place is because the cam chain tension isn't regularly or properly adjusted, so the cam chain gets loose and starts chewing into the tensioner arm. On bad cases it can also chew into the crankcase. So if you replace it with a new one, exactly the same thing will happen if the cam chain isn't regularly and properly adjusted. Second, the old tensioner arm (that is binding) can be easily repaired. What happens is, where the cam chain chews into it is right on the pivot point, so all you have to do is grab a Dremel and judiciously grind where the gouges are so the base and the pivot no longer bind. It's a very simple fix and saves a lot of money.
Hi thanks for comment. I spent a lot of money on the engineering and the new parts, matched pistons etc. I would not have felt happy repairing a badly damaged component with a Dremmel to save a few quid especially when the mating surfaces at the pivot were worn too. I have a separate video which shows how the tensioner works in practice. The new pivot runs in a brass bush which by definition allows a smoother pivot point. The tension is always on, not withstanding the problems of people not understanding how to tension properly which does lead to wear and binding. Mine was in poor condition. The new designed one was better and cheaper.
Hi I am not an expert on torque wrenches and can only advise on the one I bought which is a Clarke digital one from machine Mart in the UK. I bought it as it got a good review and I like that it beeps when you reach the desired torque. Clarke PRO236 3/8” Drive Digital Electronic Torque Wrench.
Hi I’ve found the engine rebuild video really helpful as I’m just starting my own project. I noticed you used hylomar when joining cases have you had any problems with oil leaks as I can’t make my mind up what sealant to use.
Hi - just in the middle of a restoration myself - just split the crankcases tonight (thanks to your vid) do you have a link for that cam chain adjuster part?
Too Old To Die Young cheers mate. Was it expensive to do the rebuild? I seen a 400/4 with a siezed engine and was tempted to buy it, but also scared as it i not sure how much it costs.
Well done, very good video.
Replacing the cam chain tensioner arm is totally unnecessary. Contrary to popular opinion, there is nothing at all wrong with the design/manufacture of the original tensioner arm. Firstly, the only reason it gets damaged in the first place is because the cam chain tension isn't regularly or properly adjusted, so the cam chain gets loose and starts chewing into the tensioner arm. On bad cases it can also chew into the crankcase. So if you replace it with a new one, exactly the same thing will happen if the cam chain isn't regularly and properly adjusted. Second, the old tensioner arm (that is binding) can be easily repaired. What happens is, where the cam chain chews into it is right on the pivot point, so all you have to do is grab a Dremel and judiciously grind where the gouges are so the base and the pivot no longer bind. It's a very simple fix and saves a lot of money.
Hi thanks for comment. I spent a lot of money on the engineering and the new parts, matched pistons etc. I would not have felt happy repairing a badly damaged component with a Dremmel to save a few quid especially when the mating surfaces at the pivot were worn too. I have a separate video which shows how the tensioner works in practice. The new pivot runs in a brass bush which by definition allows a smoother pivot point. The tension is always on, not withstanding the problems of people not understanding how to tension properly which does lead to wear and binding. Mine was in poor condition. The new designed one was better and cheaper.
Hi I am not an expert on torque wrenches and can only advise on the one I bought which is a Clarke digital one from machine Mart in the UK. I bought it as it got a good review and I like that it beeps when you reach the desired torque. Clarke PRO236 3/8” Drive Digital Electronic Torque Wrench.
If it’s good enough for you, it’ll be good enough for me, cheers
Great help !
Thanks a lot.
good
Thanks
Hi I’ve found the engine rebuild video really helpful as I’m just starting my own project.
I noticed you used hylomar when joining cases have you had any problems with oil leaks as I can’t make my mind up what sealant to use.
hi i have not had any oil leaks from the casing using Hylomar blue. Cheers Graham
What make of torque wrench would you recommend?
Videos are great information
Done a few of these.One of the best bikes Honda made I think.Have you got the vacuum gauges for doing the carbs after?
No I had to borrow some well actually my mate did them at his house when I went to borrow them , hence no video.
Hi - just in the middle of a restoration myself - just split the crankcases tonight (thanks to your vid) do you have a link for that cam chain adjuster part?
th-cam.com/video/cnwL7ZYBtSA/w-d-xo.html Link to camchain. Thanks
Would you be able to fiddle that new camchain tensioner in there without having to split the case?
I don't think so. Sorry.
Can you please me with how many pounds / foot I adjust the bench and connecting rod. thanks for your help
Not sure the translation makes sense. I would look for Haynes Manual on ebay for all the settings.
Y u rebuild the engine mate? Was it siezed or something
The engine was free and running but compression was down below specified. It was a hobby restoration so did the whole engine.
Too Old To Die Young cheers mate. Was it expensive to do the rebuild? I seen a 400/4 with a siezed engine and was tempted to buy it, but also scared as it i not sure how much it costs.
expensive. I needed a rebore, 4 new pistons and rings cam chain, primary chain etc cost abouit £1200 in bits.
Too Old To Die Young thank you. How long did it take you to rebuild you have been a good help?
B