xs1 Rocker Cover

[Malc S]

Hi Guys.
I have just removed my xs1b engine from the frame in order to send frame off for powder coating. Among over bodges that the previous owner/owners have achieved. the front two rocker engine mounts have been damaged, One has completely snapped off and the other is bent inwards. Would I be correct in believing that the Xs1/b Rocker cover is different to the later models due to the fact that it doesn't have a decompression linkage, the later having a four hole cover plus three ? so not interchangeable ?
I'm starting this project in the uk where none of the xs1bs were originally imported, so unless parts are interchangeable with later models they are unobtainable here.
I know its a long shot and I am struggling, Would anyone have an xs1/b rocker available at a reasonable price ?
Regards
Malc:

 

[gggGary]

I am a bit confused as to what it is you are calling a rocker engine mount? The front left (exhaust) valve) cover is different than later front left covers but it's the same as the other three covers. Rockers, rocker shafts interchange. usually recommended you keep rockers and shafts as sets... Memory says the later rocker sets have a detail improvement over early sets..
Early covers through 74 I think use gaskets later covers 75 up use o-rings, the later covers can be installed on early engines eliminating the gaskets.


The fiche shows the later model arm as a full interchange for all years, not a 100% guarantee but usually a reliable indication.
72-73 engines used a tab on the arm for the decompression mechanism, all four rockers have the tab, and I think it stayed for a couple of years afterward at least, but either type fits and works fine.

306-12151-00-00 ARM,VALVE ROCKER is used on these models and components:

1970 XS1 VALVE
1971 XS1B VALVE
1972 XS2 VALVE
1973 TX650 VALVE
1974 TX650A VALVE - ROCKER ARM TX650A - XS650B - C
1975 XS650B VALVE - ROCKER ARM TX650A - XS650B - C
1977 XS650D VALVE - ROCKER ARM XS650D - E - E006501- - F
1978 XS650SE VALVE-ROCKER ARM
1978 XS650SE-11 VALVE-ROCKER ARM
1978 XS650SE-114241 VALVE-ROCKER ARM
1979 XS650SF VALVE-ROCKER ARM
1979 XS650_2F VALVE - ROCKER ARM
1980 XS650G VALVE
1980 XS650SG VALVE-ROCKER ARM
1981 XS650H VALVE
1981 XS650SH VALVE
1982 XS650SJ VALVE
1983 XS650SK VALVE

 

[jayel]

think he's saying the upper motor mounts on the cover are damaged Gary more importantly the head and covers are line bored as a set, Malc just a cover may or may not line up correctly (bearing surfaces)... pics?

 

[Malc S]

Hi Guys

Sorry if I didn't make my post clear.
I have attached a couple of pictures showing the problem.
as you can clearly see the engine mount has been damaged (Top of the Rocker cover), being that it is cast I know that this would be a very difficult job to get welded, although it may have to be an option.
As the xs1/b does not have an electric start and therefore has no need for a Decompression device, all valve adjustment covers are three hole, Unlike the later models which have 3 covers with three holes and 1 cover with four holes.
so my question is: are any of the models made after the 1971 production interchangeable with my xs1b ?

 

[gggGary]

Ouch must have been through a serious ground / sky / ground deal. I don't think welding that would be an option (warping the cover) alignment etc.
Like Jayel says cover and head are a set. They are bored for the cam, valve cover facing etc. as a set.
If it 's not a restoration a later head-cover set could be subbed, There might be some issues with how they shaped the casting at the cylinder interface for a late to early combo.
It might be possible to "aluminum solder" those fittings to the cover... should reduce the chance of warping the cover.

 

[Malc S]

I think a previous owner has over tightened the mounts which has caused the problem, I guess a spacer between the pair of mounts once sorted will prevent any risk of it ever happening again.
I really appreciate the information received and had not realized that the head and cover are matched or bored as a set.
So I will look at a specialist welding solution, Maybe TIG and see where that takes us.