Porting

Bob Vehring · Post by **Bob Vehring** » Thu Nov 26, 2009 9:42 pm

Has anyone done the '84 update porting?

jipcee · Post by **jipcee** » Sat Nov 28, 2009 9:58 pm

Yep! Update porting and some transfer port reshaping!!
http://www.vintagevmax.com/vvforum/view ... highlight=

vmax-540 · Post by **vmax-540** » Mon Nov 30, 2009 5:05 pm

I did mine back in 85 and what a difference ,as far as I am concerned Yamaha should of made them that way right out of the box. Would of made a Great sled even better...

Bob Vehring · Post by **Bob Vehring** » Mon Nov 30, 2009 7:48 pm

Thanks for the info guys. I am abit confused, in the older post I noticed you said not to lower the intake ports. As I look at the spec's on the update page it shows lowering them 4mm, which I did. Really I had no choice. As I said somewhere here, someone before me put cast iron liners in, his job of port matching was horrible. I'm afraid I have the ex. abit to high, but had to just to clean up the mess. I an worried about this engine since I tore into it. Between the oddball cast pistons and the crappy sleeve job and who knows what else hes been into, I'm just hoping it will run for this season. Then I can look for a good engine.
My transfers look like yours, not quite finished yet but where I'm stuck is, We do 4 cy's for a living, have porting tools and a Superflow bench. I don't have a 90 deg, 1/8 grinder to get into the transfers from inside. Years ago was sponsored by a shop that had Fordom tools, but all that's long gone. Called everyone I know, but with 4 cy's we just don't use them.
I take it from the notations that that is the most important part of the job. Sure would like to get it done, but I'm running out of time. We leave soon for some southern kart races and it will be Jan before I'm back, would at least like to have the engine back in the sled before we go.