Number 2 & 3 Valves

[foreda]

Anyone ever have the #2 & 3 valves only bend on you?

[WMarshy]

What is firing order anyways, 1, 4, 2, 3 or something?

[bikerphil]

what is firing order anyways, 1, 4, 2, 3 or something?

1-3-4-2...

[skids]

If it skips a cog on a sprocket, I would think that any valve associated with that sprocket is in jepardy. It would just depend on how tight the clearances are and how carboned-up the detents are on the piston crowns.

[MPittma100]

Bent Valves

Only one reason for bent valves - something was in the way when they were trying to open. The possible culprits are either a piston or the other valve in the same cylinder. Either way, it is a serious problem that needs to be diagnosed.

You need to verify proper valve timing (timing chain, cam sprockets), valve lash, and make sure piston valve reliefs and valves are clear of foreign material (carbon). Either way the head must come off. You will find the reason as you disassemble the top end.

Another (less likely) cause is if you had excessive rod bearing wear to where the piston is coming up too far in the bore.

MP

[foreda]

Valves

Yeah. Going to pull heads and will inspect. A shame because its a low mileage engine. Compression on 1 & 4 are 150 psi! I'm thinking chain jumped a cog cranking it in the shop. It's a total restore so no hurry!
Dale

[foreda]

1980 Valves

Anybody know a source for valve replacements. Been a while since I've been on here. Had an accident a couple of years ago and just starting to get back into the 1980 MNS project.

[IanDMacDonald]

You never said intake or exhaust, but I'll assume intake. Ebay or a fellow member would be your best bet. Andreas as well. New valves are not a necessity in my opinion.

[bikerphil]

Here you go Dale....

http://www.newmotorcycleparts.com/mo...ts/valves.html

[foreda]

Valves

Looking for both intake and exhaust.

[foreda]

Here you go Dale....

http://www.newmotorcycleparts.com/mo...ts/valves.html

Thanks Phil!!