New bike, new questions

[650Skull]

setting floats and air mixture screws before identifying the carbs is like trying to get milk out of a bull..................Identify..........if unsure post pics and ask questions..........wondering why something doesn't work after doing work without knowing what your working with..........is putting the cart before the horse.

Post pics so we can help, or do a search on carb identification...........multiple threads on this.

 

[NastyBeads]

Finally got to get some pics. Please help identify what year these are. I know the choke lever is gone...haha.

Thanks!

 

[Bob Kelly III]

I'm totally guessing but My guess is BS38CV carbs
......
Bob........

 

[weekendrider]

78-79's

 

[650Skull]

I'm totally guessing but My guess is BS38CV carbs
......Bob........

Bob wins first prize.....

 

[650Skull]

78-79's

+1

 

[NastyBeads]

Thanks guys!

 

[NastyBeads]

On the note of the missing choke lever, does anyone know a good place to purchase one, or anyone have an extra they would be willing to sell? Thanks

 

[5twins]

MikesXS does sell a kit but I feel it's rather expensive. A nice used assembly is probably your best bet. Maybe Gary could help you out. And notice I said "assembly". There's more to this thing than just the lever. There's a special stepped bushing it mounts against along with a thin spring washer shim between it and the lever. There's also a small fender washer on the outside of the lever under the screw to hold the whole assembly on.

 

[weekendrider]

http://www.ebay.com/itm/Yamaha-NEW-...ash=item544d6ee275:g:bpwAAOSws5pZHPd9&vxp=mtr

 

[5twins]

That is a good deal, $7 cheaper than Mike's and I'll bet it's the exact same item.

 

[NastyBeads]

Just bought one, thanks guys!

 

[NastyBeads]

So I put the new choke on and decided to take the points covers off to see if there was any play in them possibly causing my timing to jump around so much. The points were super wobbly! I noticed there was a slotted ring behind them that would tighten them down a bit. I snugged this ring and the play was gone. The points assembly spun nicely but it seemed the slotted ring would tighten down a bit causing the assembly to slightly bind. Am I missing something? Is this slotted ring to make an adjustment? Thanks.

 

[weekendrider]

That is a picture of your advance unit. The cogged nut secures the backing plate to the cam. There is an indexing pin on the backside of the backing plate that ties the two together. If that nut gets loose the least that will happen is the advance unit is destroyed. The worst you hole a piston.
Your points are on the other side.

 

[5twins]

Somebody messed up the assembly of your advance unit pretty badly. You need to pull it apart and make it right. Don't run the bike until you do so.

That notched ring has a raised lip around the I.D. on one side. It should face out. I don't see it on yours which means the ring is installed upside down. It won't tighten down properly against the advance unit like that. There should be a scribe line on that little disc in the center along with a direction of rotation arrow. The line should align with the one to the left of the circle emblem on the advance unit backing plate. I don't see any marks on your little disc which means that is installed upside down too .....

The advance unit shouldn't spin on the cam, even if that notched ring has come loose. There's a locating pin stuck into a hole in the cam that fits into a slot on the back of the advance unit. This locks it in place to keep it from spinning. This is also required to lock the timing in correctly .....

If you were able to spin the advance unit, that means you may have lost this locating pin. You can't run the bike like this.

 

[gggGary]

Something looks weird about the weights also. One is in, the other out. Theoretically they can't do that, Both are kind of locked together by the tabs to go in and out at the same time.

 

[NastyBeads]

The bike was "running " before I purchased it. Am I guessing when I installed the Pamco, the advance rod slipped out a bit and I must have drop a pin. Is this plausible? If so, I will have to find/buy another pin and get it right. Thanks guys, I was wondering why the advance plate was spinning! Is the locating pin magnetic? It may be in some gravel....

 

[Bob Kelly III]

Yup you might find it with a strong magnet !
Good luck !
....
Bob.........

 

[MaxPete]

Those danged pins again!!!!

There is one pin on the points (LEFT HAND) side and on my '76, it fell right out while I was installing the PAMCO ignition. Fortunately, I had bought a couple of spare pins from MikesXS (they are listed in the ignition system parts list - very inexpensive - like $1.75 or so)) so I simply used one of my spares.

I'm sorry, but I cannot recall if the pin was magnetic - but I suspect it was stainless and not magnetic. One other point: DO NOT do any of this work with the spark plugs out. If my LH plug had been out, that darned pin would almost certainly have gone right into the cylinder and that would have been tragic.

I installed an e-advancer unit on my bike and noted that there are two of these pins on the advance unit (RIGH HAND) side - and they do not line up. On my bike, both were firmly stuck into their respective bores and would not come out.

Anyhow - if you have lost a pin - they are available for a very low cost at MikesXS: p/n 14-0653

 

[Bob Kelly III]

I think their just steel Pete , but I could be wrong..... I've been wrong before once or twice ! LOL
.....
Bob......