[KmanNavy]

I took my carb off to inspect it and clean the gunk out if it. I didn’t adjust any screws, change any gaskets or swap out any jets. When I put everything back together, the bike started up fine, but was running hot and the exhaust pipe started glowing hot. Any ideas why this happened? I tried to let it cool then Idle for awhile, but after about 10 minutes and a little revving, it was running really hot again. Need some suggestions if anyone has had any experience with this.

 

[KLR-Mule]

No bueno. Has it done this before, or is this the first time you’ve noticed this symptom? Perhaps it’s done this all along and your just noticing it??

Have you looked to see what your idle air mixture screw is set to? They are adjusted @ 1.25 turns from the factory. The gen 2 carbs have a metal cap over the adjustment screw that you’ll need to pry out if it hasn’t been done already.
Setting it to 1.75-2 turns will drastically decrease engine temps at idle.

Having said that, it’s not good to let these bikes sit and idle for 10 minutes. They need airflow.

 

[KmanNavy]

Good point about the airflow. The first time I started it up after the cleaning it got very hot very fast (maybe a minute or 2) after I was revving it a bit to get the system flowing again. Let it cool and then the next day tried to let it idle awhile. To be honest, I am not sure if it got that hot before, but I don’t think so. I never ran it without all the cowls on where I could see the exhaust header.

Might try to take it for a couple spins around the block that way I am close to home if it gets to hot.

Haven’t messed with the curbside idle knob either. Was trying to ensure I didn’t make too many changes at once so I cold pinpoint what was wrong.

 

[PeteK]

Read about melted airboxes in the archives. Check yours for damage, and install a thin piece of aluminum flashing on the bottom front portion of the airbox to protect it.

 

[650Stew]

Air leak maybe leaning out the mix? My gen 2 never got close to that hot on the temp gauge.

 

[Norton 850]

Air leak maybe leaning out the mix? My gen 2 never got close to that hot on the temp gauge.

That's my thinking, too.

Check the rubber manifold boot to make sure it's installed to the carburetor properly. Also, with the engine at idle you can check for air leaks by spraying WD40 around the carb to manifold and manifold to head connections. Any decrease in engine RPM identifies an air leak.

Jason

 

[pdwestman]

I'll almost bet that you may have still been on Full Cold Start enrichener and engine running fast idle at about 1800rpm when you spotted the glowing header pipe.
I'll also almost bet that your bike still has the AIS plumbing still installed that was Burning the excess gas from the cold start enrichener In The Header Pipe, causing the excessive glowing.
Totally Normal if these two conditions are true.

Also Totally Normal for the temp gauge to Rise when turning the Kill switch OFF, because the water pump is no longer circulating the cooler coolant thru the cylinder head past the temp sender near the spark plug. The fan switch is at the cooled bottom of the radiator, not in the cylinder head. So the fan turns off, but cylinder convection heating is still applied to the temp gauge sender in the head.

If the bike runs Good, Go Ride your bike.

You might consider removing that EPA required exhaust AirInjectionSystem plumbing & installing an EagleMike block-off plate to reduce header pipe heating & reduce trailing throttle After-fire popping out of the muffler.

https://www.eaglemike.com/Air-injection-blockoff-kit-AIS.htm

 

[Fetona]

Is your fan turning on?

 

[Chipper]

Gee to get that hot looks like it's WAY lean. Could you have mixed up a jet or needle shim whatever, when you took it apart. If it wasn't like that before you cleaned the carb. Something is messed up.

 

[DPelletier]

like Paul said; they'll all make the header glow if you idle it long enough, esp. with the enricher on. There is no good reason to idle a KLR for more than a minute and as long as the fan kicks on and the needle isn't pegged in the red, it's probably fine. Of course it's possible the jetting is off or there is an air leak but the glowing header alone doesn't mean anything

Dave

 

[PeteK]

It means you’re in danger of melting your airbox.

 

[DPelletier]

It means you’re in danger of melting your airbox.

Yep, one of these days I'll build better heat shields.......maybe lots of them just 'cause I can.

Dave

 

[pdwestman]

It means you’re in danger of melting your airbox.

The coolant recovery bottle nipple above the exhaust elbow might melt off first.

But most owners won't see either issue until other damage is done. Unless they visit klrforum to prevent it.

 

[Tom Schmitz]

People laugh, but the dreaded Melted Nipple Syndrome is no joke. It is worse than the heartbreak of psoriasis.

The struggle is real.

 

[KmanNavy]

Status update….. Confirmed that the fan does turn on. Enricher was off. I didn’t mess with the jetting so I’m not worried about that (just did a clean of the carb). I did find two areas wrong and the biggest was that one one side of the carb, the retaining ring that holds the rubber boot needed a bit of tightening and on the other side of the carb, the rubber boot manifold was folded into the carb which was tough to see from the left side of the bike.
The smaller issues was that I probably put way too much air filter oil on the filter and it had leaked through on the inside.

Fixed both and the bike runs much better. Feel more confident about buttoning it back up and taking it for a spin close to home now.

Appreciate all the replies.

 

[Rocketmancycle]

This is an interesting one. Please let us know what happens after riding.

 

[Surfersami]

Mine did that once and I found I accidently left the cold start enricher on.