I have a 1982 XV920R, (US model), and it has seized camshafts.
The parts are available, but expensive.

However there are options available on eBay.

Early XV750 has the same part numbers for camshafts as the XV920, (4X71217101 & 4X71218101) but later models have a different part number, (42X1217100 & 42X1218100).
Does anyone know if they are the same part, just with a new number ?

Are the cams from a TR-1 the same ?

Just trying to see what will fit.

Also, I've read that XV750 heads are a straight saw for 920 heads, and give a higher compression ratio.
Is it a simple straight swap ?

Thanks for any info.


Also, as far as I can work out, the TR-1 camshafts are 4X71217100 and 4X71218100.
Can these be used in an XV920R ?    

It doesn't matter - TR1 and XV920R are the same camshaft, with the same base-circle. The main benefit of e.g. TR1/920 cams over later ones, like LATE XV1000 or XV1100 cams is the fact that you can have them reground for more lift. If you don't plan to do this, whether you go with an XV700, 750, 920, 981(1000) or XV1100 cam will not make the slightest difference to you. When you come to the V-star stuff (BT1100/XVS1100) things change as these have a different lobe separation angle.

Hope this clears it up.

Cheers,
Greg

Hey Odradek,
here some tech Infos. See the images.

The more jounger Models contain Camshafts with an other Diameter of the inner Bearing  (25mm instead of 24mm).
You  see it on the images

Best regards Anja

ADD:
Today I had removed my Camshafts. Unfortunately the END-Bearing-Diameter is 24mm on my XV1100, J.oP. 1989
So, the early XV1100 3LP my got the standard TR1 Camshafts. The later Production XV1100 got the Diameter of 25 mm, according the data sheets abbow.

Hello, Odradek,
don´t worry about. The Oil baffle disk is mounted to that Camshaft where the Breather is lockated.
On TR1 the Breather is mounted to Cylinder head of  Cyl 2 (front). Here the Breather pipe ended in Inlet manifold for Cyl. No 1 Carburretor.

On some Models like your XV920 the Breather was placed on Cyl 1 (rear) and the Breather Pipe was led to the Cassis Frame. Sees Pic.

It is easy to change it. Just replace the Oil baffle to the rear Cylinder after install the Cylinderhead.
AND if your "new" Clinder Heads where delivered WITH Camshafts. Check it out whether the correct Camshaft is intalled to the Cyl-Heads where they belong to. (Cyl 1 Camshaft No1;  a.s.o.)

Best Regards
Anja

Hello Spotted, hi all,

as for your camhafts:
The part number 4X7-12171-01 is the right one for the rear cylinder (#1). The camshaft is marked with a "1" symbol, as shown in this picture: https://pro-formance-cycle.com/products/yamaha-xv750-xv920-camshaft-1-4x7-12171-00-4x7-12171-01

The camshaft of the front cylinder (#2) is marked with a "2"-Symbol, as to be seen here:
https://pro-formance-cycle.com/products/yamaha-xv750-xv920-camshaft-2-4x7-12181-00-4x7-12181-01
The correct part number of the front cylinder camshaft is 4X7-12181-00 or -01 (but not 4X7-12171-00). That means that someone might have swapped the front cylinder camshaft in your bike already (and put a wrong one in it unfortunately).

In general, the part number system of Yamaha includes a first section (e. g. "4X7") for the motorcycle model code, a central section (e. g. "12171") for the component itself, e. g. a camhaft or an exhaust pipe, and a final section (e. g. "-00" or "-01") which describes the revision of the component. Higher revisions usually stand for improved components, and in most cases, earlier and later revisions can be swapped. But it is not possible to swap parts with different central numbers (= component numbers).

Concerning the rocker arms, the earlier revision (4X7-12151-09-00) has been produced as a one-piece part, including a central hole for oil supply in the cam contact area. In contradiction to that, the later revision (42X-12151-00-00) got a separate insert (without the hole, but made of hardened material). The later revision is the more durable one. And you can use the later revision as a good substitute for the earlier one.

The later revision was originally developed for a later Yamaha motorcycle model (the early Virago XV 700, model code name 42X, production start in 1984). And that later revision superseeded the earlier components for the 4X7-models.

And you are right when thinking about why Yamaha changed the design: The initial central oil hole had been a "good idea", but in theory only: It lead to a local drop-down area of the oil pressure - just where it was needed most. So the design improvement was to leave out the oil hole and strenghen the material by hardening it.

Good luck for putting your puzzle together again ... .

Regards,

Roland