Update on my 80SG project & Question

[STEPPENWOLF]

Those are wells for EGT (exhaust gas temp) probes so the factory could adjust, and then seal the carbs. You should have these on all four head pipes if the exhaust is original, but a PO probably swapped on pre-80 outer pipes/mufflers...

Not being a mechanic...
Are you able to get a little more specific on adjusting carbs and then seal?
I am not a wrench turner but I try to understand the basic principals.
I have the wells and never knew why they were there.

[ViperRon]

Carbs

Steppenwolf after 1980 they made modifications to the valves and the carburetors mainly to meet emissions requirements. Part of what was done was to reduce emissions. In an effort to reduce the owner adjusting idle mixture they actually put a plug in over the idle mixture screws that most all bikes have removed now. What was done to measure the non burnt fuel was put ports in the exhaust to do sampling. There are places where cars have to do emissions testing to get a valid inspection and these were ports to also to do those tests. If you have the proper equipment and a copy of the original tech tip you can actually tune a carburetor to make the bike run cleaner. Up until last year Yamaha actually listed those tech tips on the 1980 G model of the parts lookup. Now all that is listed is the LG and SG models Not all exhaust had the ports but based on what I saw you could originally take the bike back for the update just like recall mods on cars. They also had information on putting on heavier shocks and other modifications like vacuum advance.

[Rasputin]

I have a number three exhaust vale sittinjg here in a head I will no longer be using. I will check it out and see what it looks like if you still need one. Let me know. Shipping only if it is ok once I get it out.

[STEPPENWOLF]

Wow...ViperRon..here I thought they were there to just drain condensation in the winter
Thanks and I am sure there are few others thinking the same thing.

[ViperRon]

Sorry

I sincerely apologize for the mistake of addressing this message to you Steppenwolf rather than GloweVa who was the original person requesting information. What I wrote was intended as a help for GloweVa but as I put your name on it, it appeared a hateful slam. Not my intent at all.

[STEPPENWOLF]

I sincerely apologize for the mistake of addressing this message to you Steppenwolf rather than GloweVa who was the original person requesting information. What I wrote was intended as a help for GloweVa but as I put your name on it, it appeared a hateful slam. Not my intent at all.

Gee..I thought I was "SPECIAL"..

See you somewhere down the road.

[GLoweVA]

I like the read on the EGT ports from ViperRon, Thanks.
Rasputin, Can you check that valve out for me? Thanks. Saved me $25 for ording one.
I'll PM you.

[Rasputin]

Pulled the remaining three exhaust valves from that head and all were slightly bent. Sorry.