Throughly enjoyed watching your strip and rebuild of the 400/4, I have the same bike , had it for about 9 years , it’s been taken apart on more than one occasion by different mechanics and it’s getting there! Engine rattles a little but I enjoy riding it in the summer months when the weather is good! Mine is the petrol blue also, the carbs seem to be troublesome but as I say I enjoy taking it out! I’m 68 and this is fast enough for me! I wanted one of these when they came out but I couldn’t get one for love nor money! And ended up buying the 750/4 Ps you make it look easy stripping down and the rebuild! Once again great video, and I’m going to sub to you4 channel! 👍
Nice job and I appreciate all of your videos on the process. I just picked up a very early one. Manufactured 9/74 and titled as a 1974 with numbers under 150. Looking forward to the restoration. Again, major props for your great videos.
If your question is about the noise before the bike was stripped this was normal wear and tear and bad adjustment. The video after the build was the first start before the engine had come up to full temperature. After 200 miles I adjusted the carbs, checked the tappets and tensioned the cam chain. It sound similar to other 400's I have seen. It is an air cooled multi so does sound more mechanical than a water cooled bike. The main problem noises on 400 4 are. Lumpy grinding from the bottom end and can be due to unbalanced carbs. Rattles are usually due to cam chain. A lot of people do not know how to tension cam chains on these bikes. You have the bike running and undo the adjuster not tighten it up. See my video explaining how the adjuster works.
Very nicely done, what a beauty in Varnish Blue, thx for sharing... I love this model because of its character, its look and its sound... My father owns one in Parakeet Yellow, which is still in pretty mint condition and a whole lot of fun to ride. You can see it in our videos on our channel... Best regards to the UK, stay safe & please keep it on the road
Thanks for your kind comments. I have just subscribed to your channel too as it looks like some great viewing during lockdown. I have just been told by the boss to get back out and get on with the gardening. DOH!
@@toooldtodieyoungmotorcyle Thanks mate, in my opinion you should never ever get in trouble with your boss over stuff like gardening, etc., so you will have peace of mind and get enough spare time to take care of your motorcycles and ride a bit later on as well!! Great stuff on your channel 💚, I especially liked the videos about your work on the engine, that was really very insightful and will help loads of people to put their 400s' heart back together!! We are also working on some spectacular new videos for our channel, it will still take some time to finish them, but everyone should be excited 😉 Stay healthy & ride safely, my friend!!
Congratulations..Watched the entire movie series from tearing apart to complete re-build. Loads of new learning for me, thank you very much for this amazing video. She looks Gorgeous and i'm pretty sure she will be running great as well. Cheers !!!
The only other video on restoring 400 4's has what seems to be the same rock n roll ✌out . I always loved that bike also kawi's kz series . Thanks for sharing
It is possible by anyone. Restoration or rebuilds go from just dismantle, send all the bits out for work then reassemble all the restored bits up to do everything. I wanted to do as much as possible myself. I don't have heavy engineering tools for the re-bore and aluminium welding. I was a bit disappointed when I had a broken stud in the head and not having a spark eroder (serious workshop kit) the chap who helicoiled the spark plugs rebuilt the head. I didn't ask him to do this but because I had all the bits for the head in one box he took it on himself to regrind the valves and replace the valve seals. He is a mate of mine and didn't charge me any extra. I don't have a powder coating plant or chrome shop so these had to be sent out. Apart from that I went on a welding metalwork and painting course and used a lot a you tube videos to understand electrics etc. Hope you try with a bike, soon too.
The bottom end on these bikes seems to be rough sounding and now the cam chain tensioner is good and the carbs are balanced the bike is quieter but nothing like a water cooled multi. The top end did need some work and the pistons were quiet but worn when compression tested.
I just did a resto recently and the bike runs like a champ but when it gets hot gets a little sputter here and there... have you come by this issue? The choke needs to be on when started cold but only can stay on for 2 or 3 seconds it doesn't rev up like a normal choke. Everything is stock any suggestions would be much appreciated. Great build by the way!
Not sure how to advise on this. its a case of going through the likely culprits. Carburation, Ignition (have you gone for electronic ignition?. My choke is weather dependant if it is warm no choke needed. Mid winter full choke gradually backing it off till the bike warms. Up. Good Luck.
Throughly enjoyed watching your strip and rebuild of the 400/4, I have the same bike , had it for about 9 years , it’s been taken apart on more than one occasion by different mechanics and it’s getting there! Engine rattles a little but I enjoy riding it in the summer months when the weather is good! Mine is the petrol blue also, the carbs seem to be troublesome but as I say I enjoy taking it out! I’m 68 and this is fast enough for me! I wanted one of these when they came out but I couldn’t get one for love nor money! And ended up buying the 750/4
Ps you make it look easy stripping down and the rebuild! Once again great video, and I’m going to sub to you4 channel! 👍
yep they are great bikes. having every thing stripped and clean makes the rebuild a pleasure.
Nice job and I appreciate all of your videos on the process. I just picked up a very early one. Manufactured 9/74 and titled as a 1974 with numbers under 150. Looking forward to the restoration. Again, major props for your great videos.
Good luck with the restoration let us know how you got on.
If your question is about the noise before the bike was stripped this was normal wear and tear and bad adjustment. The video after the build was the first start before the engine had come up to full temperature. After 200 miles I adjusted the carbs, checked the tappets and tensioned the cam chain. It sound similar to other 400's I have seen. It is an air cooled multi so does sound more mechanical than a water cooled bike. The main problem noises on 400 4 are. Lumpy grinding from the bottom end and can be due to unbalanced carbs. Rattles are usually due to cam chain. A lot of people do not know how to tension cam chains on these bikes. You have the bike running and undo the adjuster not tighten it up. See my video explaining how the adjuster works.
Very nicely done, what a beauty in Varnish Blue, thx for sharing... I love this model because of its character, its look and its sound... My father owns one in Parakeet Yellow, which is still in pretty mint condition and a whole lot of fun to ride. You can see it in our videos on our channel... Best regards to the UK, stay safe & please keep it on the road
Thanks for your kind comments. I have just subscribed to your channel too as it looks like some great viewing during lockdown. I have just been told by the boss to get back out and get on with the gardening. DOH!
@@toooldtodieyoungmotorcyle Thanks mate, in my opinion you should never ever get in trouble with your boss over stuff like gardening, etc., so you will have peace of mind and get enough spare time to take care of your motorcycles and ride a bit later on as well!! Great stuff on your channel 💚, I especially liked the videos about your work on the engine, that was really very insightful and will help loads of people to put their 400s' heart back together!! We are also working on some spectacular new videos for our channel, it will still take some time to finish them, but everyone should be excited 😉 Stay healthy & ride safely, my friend!!
Congratulations..Watched the entire movie series from tearing apart to complete re-build. Loads of new learning for me, thank you very much for this amazing video. She looks Gorgeous and i'm pretty sure she will be running great as well. Cheers !!!
Thank you for your kind comments
The only other video on restoring 400 4's has what seems to be the same rock n roll ✌out . I always loved that bike also kawi's kz series . Thanks for sharing
Wow!!! I would love to be able to do this !!!
It is possible by anyone. Restoration or rebuilds go from just dismantle, send all the bits out for work then reassemble all the restored bits up to do everything. I wanted to do as much as possible myself. I don't have heavy engineering tools for the re-bore and aluminium welding. I was a bit disappointed when I had a broken stud in the head and not having a spark eroder (serious workshop kit) the chap who helicoiled the spark plugs rebuilt the head. I didn't ask him to do this but because I had all the bits for the head in one box he took it on himself to regrind the valves and replace the valve seals. He is a mate of mine and didn't charge me any extra. I don't have a powder coating plant or chrome shop so these had to be sent out. Apart from that I went on a welding metalwork and painting course and used a lot a you tube videos to understand electrics etc. Hope you try with a bike, soon too.
Very good contents, only thing is it's an F as F1 is USA model
Correct the UK ones were designated F and F2
Really nice job, sounds a lot quieter, as you found the bottom ends ok, was it the carbs out of balance making it sound rough ?
The bottom end on these bikes seems to be rough sounding and now the cam chain tensioner is good and the carbs are balanced the bike is quieter but nothing like a water cooled multi. The top end did need some work and the pistons were quiet but worn when compression tested.
I just did a resto recently and the bike runs like a champ but when it gets hot gets a little sputter here and there... have you come by this issue? The choke needs to be on when started cold but only can stay on for 2 or 3 seconds it doesn't rev up like a normal choke. Everything is stock any suggestions would be much appreciated. Great build by the way!
Not sure how to advise on this. its a case of going through the likely culprits. Carburation, Ignition (have you gone for electronic ignition?. My choke is weather dependant if it is warm no choke needed. Mid winter full choke gradually backing it off till the bike warms. Up. Good Luck.
@@toooldtodieyoungmotorcyle Thanks for the info!
Possible vacuum leak, check tightness of rubber boots between carbs and intakes also check for cracks.
why is it sound noisy like grinding is it normal?or have loose tappet screw?
That is most definitely normal. I used to race one back in the day just needs an open header ;)