Last Minute Adjustments - Running HOT! REALLY HOT!

[kboehringer]

XS11 Friends,
My UGLY DUCK is running really really hot.

I haven't driven her too much lately but had made some recent repairs/upgrades(2). I replaced the carb boots and the coils with new DYNA 3.0's.

The bike had been running rough and the coils did not pass the OHM check. I had a set of aftermarket replacement boots waiting in the wings and changed both items. This was a few months ago.....I had taken her for a SHORT ride and the rough was gone and I was pleased. I made no carb adjustments or other.

In preparation for the Vintage Yamaha Rally in Stecoah I've been on this steed a lot lately including a nice ride to work this morning (35 miles). I've noticed the bike is SMOKING hot. Can't even hold a hand on the cases. This is not normal. I'm also noticing a little blue on my head pipes....

• I notice the cheapo carb boots seem to "Pulsate" as I assume they don't have the aluminum inside like the OEM. But, my vacuum gauges do not indicate an air leak..... Pretty close to rock solid.....
• The valves were adjusted not much more than 1000 miles ago so I haven't checked there.
• The '80 carbs are jetted to the OEM spec.
• I'm wondering what these high power coils are putting into the equation? Anyone else experience this with these new coils?
• Clearly this is acting like a LEAN condition, but I don't see any evidence other than the hot as heck motor.

I've got little time but am considering going up a size on the mains.... I'm leaving tomorrow for Stecoah and this is now risky business...

Quick Thoughts?

Sincerely,

[spectra]

Are you sure there are no leaks at the new boots? I replaced mine and all seemed well until I gave a squirt of starting fluid around them........motor raced so I knew there was a problem. I had to make thicker gaskets to solve the problem.

[kboehringer]

Carb cleaner tried NO RACE

Are you sure there are no leaks at the new boots? I replaced mine and all seemed well until I gave a squirt of starting fluid around them........motor raced so I knew there was a problem. I had to make thicker gaskets to solve the problem.

Spectra,
I'd tried it before but just did it again following your idea..... NO Change. I used carb cleaner on a straw at every seam on the clamp area and the mating surface to the head. Shot into the REAR INTAKE of the carb, it will race....normal...

Sincerely,

[JeffH]

Kurt,

I've been following this HOT issue with Ugly Duck. Seems you can't find any smoking gun, just hot motor.

I don't know, air cooled beast and oil. You sure oil is flowing all the places it needs to splash? New coils wouldn't do it. If it is running great then it can't be a fuel flow restriction or timing all jacked up.

The list of what makes it that hot isn't too long. And you think all 4 cylinders rowing equally? You know these carbs as well as anybody so its not likely that. Bike rolls OK? so not like something stuck or brakes dragging.

Jeff

[kboehringer]

Kurt,
The list of what makes it that hot isn't too long. And you think all 4 cylinders rowing equally? You know these carbs as well as anybody so its not likely that. Bike rolls OK? so not like something stuck or brakes dragging.
Jeff

Jeff,
Thanks for the response. Just got off the phone with Marty. I ran home at/about 4k on the tach. He's thinking I'm not even into the mains yet so a 1/2 turn on the idle jets may do the trick. Why the devil this normally very well running machine would run so hot is a mystery.

• The plugs look nearly perfect light tan/white electrode.
• Brakes are good no drag.
• Runs like a bat-out-of-hell in the upper RPM range, SCARY fast SOB.
• Maybe a LITTLE sluggish in the 3-4k range (especially when warming up).
• Idles perfectly.
• Starts nicely.
• Haven't checked compression..... Maybe next?

Pulled the seat and about to tweak the low speeds. I really cant test this mod until I'm at the lodge. Gonna take my jet kit too..... If it's still hot I'm likely to end up on the FJR for the rides..... I didn't spend ANY time preparing the Mayberry Duck and she needs a couple items fixed including an exhaust leak so she's a no go too.

More thoughts.

[madmax-im]

Bring your vintage bikes and put them on display ..Ride the FJR...ya know ya wanna...

[kboehringer]

Display bikes....

Bring your vintage bikes and put them on display ..Ride the FJR...ya know ya wanna...

I will be driving the DEAD DUCK up to the lodge so I will be on an XS11. It runs absolutely great (a little funny when cold) but it's been on several 200 mile+ trips. It's a one-seater now in the "Café" style so Nancy can't ride along on that one. After all her hard work on the Rally prep she wants to ride!

I made the 1/2 turn adjustment to UGLY DUCK but only a 20-30 mile ride will show if the heat is down any. If it's a nice cool Saturday & Sunday I'll run the risks. Otherwise I'll pull the FJR out of the rental van and go riding on it.

As you know Ben, I am getting really SPOILED by the newer machine. HOWEVER, I've been on the XS11 & XJ550 quite a bit lately. I've been RE-BITTEN by the XS11 BUG. That Ugly Duck DOES run like a dream in the higher RPMS and I'm not so sure if my FJR would beat her up too badly in a straight line run.

KURT

[skids]

Stock plugs, or are you using a hotter plug? Fuel bowl heights right in the middle? Are you using 4 into 1 exhaust? What jetting are you using? It is difficult to say what is going on without knowing what carb configuration you are using (did I miss it in the thread?) Also, sitting in the garage idling can cause a lot of heat and single walled pipes can show a lot of heat.

[kboehringer]

Stock plugs, or are you using a hotter plug? Fuel bowl heights right in the middle? Are you using 4 into 1 exhaust? What jetting are you using? It is difficult to say what is going on without knowing what carb configuration you are using (did I miss it in the thread?) Also, sitting in the garage idling can cause a lot of heat and single walled pipes can show a lot of heat.

Skids,
Model SG
Stock Plugs - BP6ES NGK - Tan/White
Fuel Bowl Heights - Perfect - Just Checked (has 81 Bowls)
Stock Head Pipes (4->2) into Harley Dyna Glide Muffs. Been running these on this bike in this configuration for years.
Stock Air Box
Stock '80 Carbs (except the better 81 bowls) Stock Jetting ALL MIKUNI parts. Stock Jetting.

Recent Changes....
DYNA 3.0 Coils (No Ballast Resistor)
Aftermarket Carb Boots - Several leak checks performed....No issues found.
Idle Speed now at 2.5 Turns.

[Radioguylogs]

For reference, my SG (the Bagger) was too rich at 2 turns out on the idle mixture screws- it wouldn't drop back down to normal idle RPM.

I have them at 1.5 turns and she is very happy. (Stock airbox and stock pipes.)

If 2.5 turns doesn't help, then the problem seems to be somewhere else. It is so strange.

[skids]

Harley muffs might be more freeflowing requiring a higher main jet. I would definately change with regular heat range plugs which might help a little. NGK 7ES. If you are using the oring and washers under the pilot screws, you might consider backing the pilot screws to 3.5 turns out. That is what I had to do with my 81H carbs on a 78E. The later model carbs use the idle circuit for more of the range of rpms than early model carbs. I think you can get idle a bike to idle at 1100 rpms with compensation of the idle adjustment knob, but as you run the bike above 1100 rpms, you are really not using the idle circuit at optimum mixture. (Not sure if I am making sense here, but baking off the mixture screws workied for me).

[skids]

I tried harley muffs once and found a dead spot in the rpms around 2800 rpms. I can't remember which bike it was or what carbs, but it was likely due to a overly lean condition. If this is the case for you, you might just try running at 3500 rpms or more until you get things sorted out...

[Eveready1100]

Kurt, Not sure what type of gas you have available over there, but with our current rubbish over here, your white/light tan plug colour would be on the lean side of things. Can you raise the slide needles on your carbs to feed a tad more fuel through in the mid and upper rev ranges? I did that on my SF to stop a pinging problem I had a few years ago.