First Ride Report

[79XS11F]

Took my bike out for a run this evening. WOW she is "BUZZY" for lack of a better description. Can't see anything in the mirrors. Idle crept up to about 1400 once well warmed up. Brakes are a little soft for my liking and the turn signals do not work.
She idles smooth enough at 1000 but gets lumpy below that. She seems to miss a little just off idle. This might be fuel starvation because the fuel petcocks are hit and miss. Sometimes the vac requirement works .. and sometimes they don't I'm currently running them set to prime. So the "BUZZ" and the miss off idle are the first items to address.
Any ideas about the "BUZZ"?
Rob

[prometheus578]

Does it buzz only when moving, or can you feel a good buzz when you're just sitting still?
(yes, yes, TRBIG, we know... you can feel a good buzz whether you're sitting still or lying on the couch)
What I mean is... Does it buzz only when moving, or can you feel the vibration through the handle bars when Idling on the sidestand, or revving it a little.
Is it an engine buzz... or front end/tire related.
Either can shake the mirrors.

[79XS11F]

Hey Prom .. She is buzzing across the board. Worst with acceleration then at idle. She tracks good with no pull to ether side. Can feel "buzz" in handle bars and in seat. She is however idling well enough to not think there is a miss at idle
Rob

[trbig]

Ah Pro.... My poor misguided child of the 60's friend. In your assumptions that everyone has the classic "flashbacks" that you have from governmental LSD tests.... with a little experimenting from you on the side... (Might explain the mood swings??) A buzz while sitting on the couch OR standing still is, well.... a buzz kill! lol.


Once YOUR buzz subsides, you might use your truly Guruship knowledge and give this poor gentleman some answers... instead of answering his questions with questions?!?

Rob,
If the idle is going up on you a bit when it's warm, it makes me wonder... have you cleaned the carbs up good?? If so, have the carbs been synchronized?

I can have questions.... Pro is supposed to have all the answers!


Tod

[TopCatGr58]

Hey Rob,

Feeling a buzz in the bars sounds like the engine mounts may not be doing their job to isolate the engine vibrations, or you have something attached to the engine that is hitting the frame, like muffler mounts?

My engine will idle around 1k rpm when just first warmed up to where it will idle without enrichener, but after I've ridden it a bit and really gotten it warmed up, the idle will run a bit higher due to the leaning out affect!
T.C.

[79XS11F]

Yes the carbs have been synced and there does not appear to be any vac leaks. I sprayed quick start around them and no change in idle speed of engine sound. I will check for parts contact points tomorrow TC. Keep you posted
Rob

[prometheus578]

"I agree with T.C., but never with TRBIG"

(One only learns answers by asking questions. It's knowing that there are questions to ask... which is the tough part)

I too was thinking mounts, T.C.
After rereading his previous stuff....
An engine will also seem to be idling nicely on three cylinders, too.
Start the bike... let it idle for a minute, and then get a spray bottle and spray each header pipe. If they all sizzle about the same, then you can almost rule out the three cylinder thing. Of course, this will only check the idle circuit fuel.
I know this sounds silly, but recheck that the plug wires from the coil on the left go to #1 and #4, and the right coil #2 and #3.
Also... pull the plugs and see if they're all burning the same.
I'm trying to recall from your previous issues... did you ever get the compression thing straightened out? What was your final compression reading across the board?

[79XS11F]

My intention is to run the bike for a few days to loosen things up and then check the compression. I already changed out the oil due to the flooding thing. If compression is still off on Friday after work I will pull the head on Saturday and check it out / clean it up. I already have a head gasket and should be able to do that job in a day.
Rob

[prometheus578]

well, before any major surgery, recheck valve clearances.

[79XS11F]

Yes I would check valve clearances before jumping in. Now when I got home from work this afternoon I was not really surprised to see a small puddle of gas under the bike. Fing CARBs. Man I have triple cleaned them triple tested them and they alway check out on the bench but not on the bike GRRRRR.
I also took some temperature readings off the headers and got these numbers
1 =314* F. MAX
2 = 300* F. MAX
3 = 272* F. MAX
4 = 384* F. Max

I tried to keep the Lazar at the same position on each header when doing this There is a mis-fire and i will bet it is #3 but that bigger number on #4 is also a red flag. It must be ether running lean or the others are rich. i really have no idea what sort of temperatures the headers should produce.
Rob

[Ken Talbot]

Remember, Rob, a puddle of gas means you have at least one leaking float valve, AND you also have at least one leaking petcock. If the float valves are all good, it won't leak. If the petcocks are both good, it will not leak. You need to fix both problems to be sure.

[79XS11F]

Got up this morning and NO GAS anywhere. Every thing is working properly again. The issue with the fuel cocks appears to be intermittent. I am sure the little valve under the vac nipple cover is at fault. I noticed while rebuilding them that sometimes it worked and sometimes it didn't. Can this part be soaked in carb cleaner to remove fuel gum if that is what is causing the problem with that little rubber valve. it is not removable because it is crimped into the nipple cover.
Rob

[skids]

You can take the Oring with you to the hardware store and size a replacement (get nitril butyl or gas proof) and polish the conical seat with mother's milk compound.

[pggg]

79, there's a diaphragm in the petcock that has a tiny breather hole in it, gotta be lined up to the breather hole in the petcock

[79XS11F]

The insides of my petcocks are rebuild kits and I did line up the breather holes. If you look at the back side of the cover that has vac line nipple on it you will see a tiny one way rubber diaphragm housed in a circular steel disc. It is crimped into that cover. that the part on my petcocks that is working intermittently. The bike will idle at 1K but is lumpy to say the least.

Now I just got back from a ride and the engine is missing for sure and that must be causing the "buzz" I am feeling in the foot pegs, seat and handle bars. I checked the engine and the only parts in contact with the engine are the parts that are suppose to contact it. That's the engine mounts to frame, carb boots to carbs, exhaust system hanging from exhaust ports all the way back to the rubber mounts at the rear foot pegs. Nothing else is touching the engine.
I did manage to get the turn signals working :-) Buzzing has already burned one factory tail light bulb.
So I guess I will be at it again this weekend .. check plugs, check valve specs and compression, etc
Rob