550/673 Head arrived-inspect

[Kara25]

Ok so today the head for the 550/673 swap arrived. This thing actually seems in better condition than my 550 head as far as wear in my novice eyes. There is not ONE stripped thread in the whole head exhaust,carb boots, cam holders nothing. Only thing that gave me worry is that due to inproper storage perhaps 2 of the exhaust valves caught some rust. Planning to break everything down replace valve seals and mesaure springs etc. If worse comes to worst are my 550 valves interchangable with the 650 head?? i will try cleaning them but i assume if i finding pitting on the valves they are trash.The cams are SPOTLESS lobes look like they havent even been run. But i will be using my 550 cams anyway. Here are the pics. Tell me what your keen eyes see. Head by Geo 25, on Flickr Head by Geo 25, on Flickr Head by Geo 25, on Flickr Head by Geo 25, on Flickr Head by Geo 25, on FlickrHead by Geo 25, on Flickr

[Nessism]

Looks good, assuming you also received the cam caps.

I'd pull the valves, and check valve to stem clearance via the "wobble test" as detailed in the factory manual. Assuming the guides are fine, my advice is to find someone with a centerless valve grinding machine and have them kiss the valves, both the face, and the stem, to clean them up. This will make the sealing face like brand new. Then lap them into the seats. Don't lap like crazy, just a light lapping to clean the seat and check the sealing pattern. If the pattern is bad, or the seats heavily pitted, the seats should be cut instead of just lapping and lapping. When done with this part, install new viton valve stem seals.

[Kara25]

Yes of course also got the caps. Plan of attack will be the same as the 550 top end 3 years ago. Multiple hot baths with water and dishsoap agitation with brushes and kerosene and repeat repeat repeat. Valves i will perform the test after removing the heavy grime of the head. Also got the cover only misshap with that is 1 of the 4 cosmetic round things is cracked otherwise all good. The big question is if i can use all the 550 hardware on the top end nuts,accorn nuts,cam cover bolts etc and if the torque specs on the heads are the same beetwen the 550/650 that would be ideal. Also if anyone knows are the cam chain guides beetwen the 2 models interchangable??? Seems inevitable after a lot of thought to NOT open the bottom end so guides will be replaced if they are the same on the 650.

[Kara25]

Nessism i got 8 valve stem seals from a gasket set for my 550 back in the day they are not OEM but in closer inspection they have a V engraved on them on the rubberized part on top which i assume means they are made from viton.? They look exactly like the ones on the link i posted. What do you think can they be trusted or they will start leaking in no time?

[Suzukian]

A little Brake Fluid will make them expand and soften them up, if they are hard. Don't soak them in Brake Fluid, rub it on, get it wet, and let it sit, but don't do too much, it makes the rubber swell.

[Kara25]

Suzukian Thanks for the tip i will use them i dont see more experienced people than me objecting on usage of non oem valve stem seals like they do for example on gaskets so i trust that they know something more.