XR vs CG clutch cover interchangeability?

[franque]

Hi guys, just wondering if anybody knows if you can use an XR right side cover (clutch cover) on a CG motor? Just curious, I tried searching and couldn't find anything. It says it's a Zongshen ZS167FML, although looking back at some old posts, I'm pretty sure it actually had the 63.5mm bore instead.

[NzBrakelathes]

Why not just use correct cover?
XR is duff animal well depends what XR maybe as well

[pete]

the XR never used the CG motor....
they were/are all OHC not push rod
as in the CG motor...


.

[franque]

Originally Posted by NzBrakelathes

Why not just use correct cover?
XR is duff animal well depends what XR maybe as well

Because I don't want the super high-profile cover that is on it, because it interferes with the XR kickstarter in an XR (specifically 200) frame.

I think that I found out what I need, a CB125S cover. The XRs (for the vertical CB-esque motor) have an extra bolt and shaft that will interfere.

I ended up doing some digging, and found out it probably will not work with a standard XR cover, while the Brazilian made 125 motors, both pushrod and OHC, seem to use the same cover.

Unless you know of a low profile Chinese made CG right side crankcase cover?

Originally Posted by pete

the XR never used the CG motor....
they were/are all OHC not push rod
as in the CG motor...


.

Yeah, I know, just trying to figure out interchangeability.

[Weldangrind]

Does the Brazilian motor have the sight glass? That's a nice feature.

[Wild Dog]

The XR 125 was OHV till 2011 then they switched to OHC. Those xr 125 made till 2011 are just CG engines. The little XR 125 are the base of most of these chinese on/off motorcycles..



If it is worth something, this is a clutch cover for an XR 125 OHV.



They can be bought new from Honda for about 75 usd, but i think you are just going to waste money, i doubt it will fit an XR200.

[franque]

Originally Posted by Weldangrind

Does the Brazilian motor have the sight glass? That's a nice feature.

No, I don't believe that they do.

Originally Posted by Wild Dog

They can be bought new from Honda for about 75 usd, but i think you are just going to waste money, i doubt it will fit an XR200.

I'm not trying to fit a CG cover on an XR, but the other way around. Thanks for the picture btw, it confirms something that I suspected.

From what I can observe, I can conclusively state that an XR 185/200 cover will not fit on a CG motor. I would consider these engines to be of the same "family" within Honda, and there were three different styles of covers that Honda used over the three main phases of engine development. Additionally, I will show pictures of the three different styles of covers, and also cover the differences in engine architecture that correspond to the changes in covers and redesigns in the family of engines. Post to follow.

[franque]

The chief difference between clutch covers (aka right side crankcase covers) is 11 vs 12 bolt covers. One can see the differences in shape with gaskets:

11 bolt:


12 bolt:


Initially, Honda introduced what I would call the mk. 1 of this engine. I believe that they produced it in 100cc and 125cc engine displacements. They had one piece cylinder heads and 14mm wristpins. The clutch side crankcase cover has 11 bolts and has a similar style of clutch adjustment to Honda's centrifugal clutch models. While I am sure that this style of cover will bolt on to any other 11 bolt cover, the method of clutch actuation is different from later models, with the cable pull being more vertical than horizontal, and I'm not 100% positive that the clutch cover would work on later 11-bolt clutch covers. I believe that this was produced from '70-'73.

Mk. 1 Front:


Mk. 1 Rear:


With the Mk. 2, there were a number of changes: switch to a two piece cylinder head, change to a more "horizontal" clutch pull, which uses the clutch cover bolts to also hold the clutch cable retainer. For Japanese production, the Mk. 2 was produced for a relatively short time, I think from about ~'73-'78 or '79. I believe that this cover/Mk. 2 motor was introduced with the TL125S. The displacement in OHC was only 125cc, but for OHV it ranged from 125cc to 223cc There was also an upsize of the wristpin to 15mm.

Mk. 2 Front:


Mk. 2 Rear:


An additional note for the Mk. 2, as far as I can tell, when Honda upgraded to the Mk. 3, they sent the tooling for the Mk. 2 engine to Brazil, where they also set up the CG production factory. All of the Brazilian produced motors, as far as I can tell, are of the Mk. 2 variety, with there not being any Mk. 1 or 3 motors produced there. All of the CG covers appear to be Mk. 2, with some variants, particularly the hole for the kickstarter and seal not machined out for some Brazilian-produced motors, particularly the Honda NX125. It would also appear that the CRF150/230 motors (also made in Brazil) use an 11-bolt clutch cover, but I'm not able to ascertain how similar it is to the Mk. 2. I had a Brazilian-produced 1985 CB125S which had the Mk. 2 cover, and the smaller spigot diameter of Mks. 1 and 2, and thus I wasn't able to install the CB150 big bore cylinder/piston because of a spigot that was too small, indicative of a Mk. 1 or 2 motor.

The Mk. 3 was a significant upgrade to the engine series. Honda introduced it into the US with the XL185. As far as I can find, any Japanese produced engine post 1979 until '02 will have all of the Mk. 3 upgrades. The clutch cover was changed to the 12-bolt model to incorporate a decompression lever to facilitate starting, the cylinder spigot was increased to 70mm diameter, and the deck height was increased by 12mm (if I remember correctly). It was available in displacements between 125cc to 200cc. Again, as with Mk. 2, there are some minor variants, particularly with the casting not machined for a decompression lever.

Mk. 3 Front:


Mk. 3 Rear:

[NzBrakelathes]

The oil centrifugal filter needs the depth huh

[NzBrakelathes]

Originally Posted by Weldangrind

Does the Brazilian motor have the sight glass? That's a nice feature.

Some Chinese have the side glass
Not all thi

[Weldangrind]

Originally Posted by franque

The clutch side crankcase cover has 11 bolts and has a similar style of clutch adjustment to Honda's centrifugal clutch models.

Are you referring to a vertical motor with a centrifugal clutch? If so, which years / models would be so equipped?

[franque]

Originally Posted by NzBrakelathes

The oil centrifugal filter needs the depth huh

I've had a CB and CG Mk. 2 apart side by side, I'm fairly certain that besides some small differences, like having a kickstart or not, or having/lacking a counterbalancer (which I'm fairly certain nothing Japanese/Honda produced had one), or small differences in clutch baskets, everything on the right side of the Mk. 2 motor, at least in terms of architecture, is the same.

Originally Posted by Weldangrind

Are you referring to a vertical motor with a centrifugal clutch? If so, which years / models would be so equipped?

No, while they were vertical motors, they weren't equipped with a centrifugal clutch, the clutch arm pivot (inside of the clutch cover, please look above at the Mk. 1 pictures) was adjustable in lieu of having a cable adjustment attached to the front of the engine, as shown below for the Mk. 2/3 style of clutch actuation:

Cable bracket:


Adjustment procedure:


That being said, there is the possibility (no guarantees), that if you wanted a centrifugal clutch, you might be able to fit some ATC 200 pieces. Looking quickly at it, it looks like it might be a strange Mk. 2/3 hybrid (I think that it has the taller deck height and spigot diameter of the Mk. 3 cases, but it looks like the Mk. 2 clutch cover style). If you were really curious, I would just buy an ATC 200 for cheap, or a complete motor, and see what fits.

Edit: I looked again at the ATC 200 motors online, it might be more of a Mk. 3, it looks like it's a 12-bolt cover, but the cases are definitely different than a conventional Mks. 1-3.