HOT left cylinder

[roadventure]

A few days ago I took a short ride (15 miles) and noticed the left cylinder was unusually hot. When I returned home the header was blue near the exhaust port. The right side was it's normal bronze color.

Any suggestions on what I should look into for a cause, and correction to this? FYI, I adjusted valves (.008 exhaust, .006 intake) around December 2020 and have only added about 1500 miles since then.

Thanks!

 

[Skip Stauber]

A few days ago I took a short ride (15 miles) and noticed the left cylinder was unusually hot. When I returned home the header was blue near the exhaust port. The right side was it's normal bronze color.

Any suggestions on what I should look into for a cause, and correction to this? FYI, I adjusted valves (.008 exhaust, .006 intake) around December 2020 and have only added about 1500 miles since then.

Thanks!

Hi Roadventure, Sorry to hear, I usually check my cylinder temps just above the exhaust flange after every ride using a infrared thermometer and they are both usually around 235 - 240 F. Thought this might help. Skip

 

[roadventure]

Hi Roadventure, Sorry to hear, I usually check my cylinder temps just above the exhaust flange after every ride using a infrared thermometer and they are both usually around 235 - 240 F. Thought this might help. Skip

Thanks, but no digital temperature gauge here.

 

[GTM®]

As a crude test, remove both injectors and try to start allowing them to spray and visibly see if they look even side to side. If not, the left side may need professionally cleaned. Ethanol and/or contaminates are the enemy here.
As an aside, check the valve lash again just to verify... things can happen.

 

[roadventure]

As a crude test, remove both injectors and try to start allowing them to spray and visibly see if they look even side to side. If not, the left side may need professionally cleaned. Ethanol and/or contaminates are the enemy here.
As an aside, check the valve lash again just to verify... things can happen.

Thanks. Now I will learn how to access the injectors. Hopefully in the service manual.

Do you think it would be worthwhile to try Techron (or some similar cleaner in the gas)?

 

[GTM®]

Do you think it would be worthwhile to try Techron (or some similar cleaner in the gas)?

NO.

 

[Skivo]

A few days ago I took a short ride (15 miles) and noticed the left cylinder was unusually hot. When I returned home the header was blue near the exhaust port. The right side was it's normal bronze color.

Any suggestions on what I should look into for a cause, and correction to this? FYI, I adjusted valves (.008 exhaust, .006 intake) around December 2020 and have only added about 1500 miles since then.

Thanks!

Assuming your machine use throttle bodies, check for air leaks post-fuel delivery point. An air intake leak somewhere around the intake boot would cause the affected side to run hot/lean. This happened to me on another bike, but in my case the bike ran horribly. Did yours run normally otherwise? Like the others said, a clogged/dirty injector is a likely culprit too.

 

[Kevin.NZ]

To narrow it down you could swap the injectors over and see if the fault follows

 

[GTM®]

Assuming your machine use throttle bodies

Don’t assume. Single throttle body on all 1400s. An air leak would mean high RPM revs at closed throttle.

 

[roadventure]

To narrow it down you could swap the injectors over and see if the fault follows

Good point! First though, I need to find the injectors and how to remove them.

 

[roadventure]

Don’t assume. Single throttle body on all 1400s. An air leak would mean high RPM revs at closed throttle.

Todd,

The bike seemed to run normally except for the HOT left cylinder.

 

[Moto-Uno]

The simple test for any intake leak is to simply spray wd-40 around the intakes (downstream of the butterflies)
and note any change in engine rpm , if there is any it's got a leak . Peter

 

[roadventure]

I did get the injectors removed and cranked the engine standing so I could see both of them. Visually they both seemed to be putting out the same amount of fuel. So, I put them back and started the bile just to make sure it would.

Guess, next I'll check the valve clearance just for fun....

 

[roadventure]

I did get the injectors removed and cranked the engine standing so I could see both of them. Visually they both seemed to be putting out the same amount of fuel. So, I put them back and started the bile just to make sure it would.

Guess, next I'll check the valve clearance just for fun....

My garage gets full sunshine this time of year so I don't spend a lot of time out there do to the heat and glare. BUT, I did remove the cylinder valve covers (and spark plugs). The LEFT side plugs show signs of having been siginificantly hotter. I was not surprised since the left cylinder was noticibly hotter.

The fuel injectors appeared to be functioning equally. What else could cause one cylinder to suddenly run hotter?

 

[GTM®]

My garage gets full sunshine this time of year so I don't spend a lot of time out there do to the heat and glare. BUT, I did remove the cylinder valve covers (and spark plugs). The LEFT side plugs show signs of having been siginificantly hotter. I was not surprised since the left cylinder was noticibly hotter.
The fuel injectors appeared to be functioning equally. What else could cause one cylinder to suddenly run hotter?

Partially clogged injector not detectable to the eye by the test you did. Left side injectors for kick-standed Winter stored bikes seems to have more issues with left side injectors. I would send them out to a place that does documented testing and balancing like RCFuelInjection.com

 

[roadventure]

Partially clogged injector not detectable to the eye by the test you did. Left side injectors for kick-standed Winter stored bikes seems to have more issues with left side injectors. I would send them out to a place that does documented testing and balancing like RCFuelInjection.com

Okay, but the bike is stored vertical over the winter. I don't doubt that the kickstand lean could be the issue though as it can spend five or more days on the kickstand normally.

Found a company nearby (Injector-Rehab, Blackwood, NJ 08012). Will get their "Dynamic Cleaning" service.

 

[GTM®]

Okay, but the bike is stored vertical over the winter. I don't doubt that the kickstand lean could be the issue though as it can spend five or more days on the kickstand normally.
Found a company nearby (Injector-Rehab, Blackwood, NJ 08012). Will get their "Dynamic Cleaning" service.

Perfect, wasn't saying your was stored that way, just noting observations we have of those in house that had this issue. Post what the report says. If not the injectors, there has to be an air leak somewhere. My bet is on the injector.

 

[BrianR]

My garage gets full sunshine this time of year so I don't spend a lot of time out there do to the heat and glare. BUT, I did remove the cylinder valve covers (and spark plugs). The LEFT side plugs show signs of having been siginificantly hotter. I was not surprised since the left cylinder was noticibly hotter.

The fuel injectors appeared to be functioning equally. What else could cause one cylinder to suddenly run hotter?

My Stelvio wasn't running very well, and I "cleaned the injectors", which didn't improve things, so I took them to a specialist who said that they couldn't be balanced and that the left one wasn't even working (hence not able to balance), and likely caused by my mechanics hamfistedness in removing them...my mechanic being yours truly

 

[Moto-Uno]

That's one of those "bitch slaps" we get every now and then . . Peter

 

[roadventure]

WTF! Okay, NOW, what tool do I need to remove fuel line from the injector? I have attempted to find out through various internet searches and have been unsuccessful.

Helpful information would be:

1. you don't need a quik-connect removal tool. "here's what to do...."

2. the fuel line removal tool you need is "blah blah, part number XXXXXXX"

for example.

Thanks again.
Trying my utmost to NOT become a MG fuel injection expert