Help - Bike idles and runs hot - bigger pilot jet?

[Kyleot]

I have had some trouble the last several months of my bike (05 TC450) idling hot and boiling over often. Many times after stopping I have about 15 to 20 seconds to idle before I boil over. I haven't adjusted my jetting yet because I have great throttle response and overall good performance I just have to keep moving... I am getting my son into riding with me now, but have had trouble now waiting for him to catch up and coaching due to my heat problems. I am thinking that may be I need a size or two larger pilot jet. I have tried different coolants and looked for fans, but have had no luck. Any ideas or suggestions would be appreciated!! Thanks for the help!

 

[OlderHuskyRider]

Possible leaky head gasket, possibly caused by loosened head bolt(s).

 

[Freaky]

Are your radiators OK? Not blocked or bent?

 

[Kyleot]

Quick update : Tonight I warmed up the bike, and ran at a high idle. Slowly closed the air fuel screw. No change in the bikes engine speed. Slowly opened back up to 4.5 turns open before bikes engine rev'ed up like expected. I think I'm running lean. I'm going to check to pilot size and look into a larger pilot. Sound like the righ track? Radiators are good, and top end lots are torqued. Thanks again for the help!

 

[OlderHuskyRider]

Clean the pilot jet with a single strand of copper speaker wire, wrapped around your finger to make a floppy spring-like shape, drag that thru the jet a couple of times, see if it looks any bigger by looking thru it at a light.

 

[Kyleot]

Thanks! I will give t a try and repost how it goes.

 

[OlderHuskyRider]

I have had some trouble the last several months of my bike (05 TC450) idling hot and boiling over often. Many times after stopping I have about 15 to 20 seconds to idle before I boil over.

Also check your rubber intake boot for leaks.

 

[Kyleot]

Quick update - I ended up replacing the #42 pilot with a #48. I haven't had a chance to ride it yet to confirm, but it did get air/ fuel screw down to 2 turns, from the previous 4-5 turns open with the 42 and 45. I am hoping to give it a go today and check to see how everything adds up. "Older" - I hadn't thought about the rubber intake boot, but I'll check it too. I replaced that within the last year, so as long as it's on tight... It should be okay. Also, I tried cleaning out the 42 with some wire as you suggested, and it was a little gummed up. But I still think it was too lean from the get go. I will repost after I get a chance to ride and check it out.

 

[OlderHuskyRider]

but it did get air/ fuel screw down to 2 turns, from the previous 4-5 turns open with the 42 and 45.

That's makes good sense, that many turns on the smaller jets indicated athe need to go bigger, your gas mileage should go down as well as your operating temps, and power should go up!

 

[Wade]

I'd sure like to know how your situation turns out, cause if your 05 TC issue is anything like how my 04 SMR was with overheating and boil over for the past 2 years along with losing clutch.... here is what I tried and eventual resolution. Bare in mind that the bike would idle great and had loads of power and torque, however, after about 45min, would start to rise in temp (and lose clutch) all of a sudden on a hard ride or anytime at idle..... Only continuous riding at around 40mph would the bike temp remain normal.
I replaced all of the following with varying results but same same eventual overheating (or should i say temp going out of control on the gauge i put on, so i would shutdown motor way before boil over).

Oversized fuel tank back to orig so as to allow more air flow thru radiator
Larger main jet
Larger pilot jet
Radiator Spal pull fan on right hand side
Spark plug
High flow water pump
High-flow radiator
Silicon hoses
Radiator caps
Various coolants of all the top brands
Checked water flow passages numerous times
Radiator fin guards on and off
Vortex Ignition back to Orig Ignition
Down graded exhaust and header with good restriction
Oil pump and all bearings changed out
Piston, rings, connection rod and bearings
Various Oils (Belray, Royal Purple, Castrol)
Basically i went back to full stock

Then as a last ditch effort, I read somewhere of a cylinder being porous so instead of getting a new cylinder and spending that funds not knowing if that would be a waste as well cash as well, i sent the cylinder to rebuild by Halls and ordered piston/rings and a "Y" hose connector to replace the orig "T".

Once we put back in the rebuilt cylinder with piston and the Y hose connector, both the clutch and overheating issues have gone away. I can idle for long periods and hardly remember that i have a fan to turn on. We can ride long hard runs and she is normal on the temp and the temp would vary as would be expected for the condition of the ride and style.
I have put back all modifications and still no issues for like 5 months now.

After over two years of high temp and clutch fade issues, just thought i'd share my experience with you all.

 

[OlderHuskyRider]

After over two years of high temp and clutch fade issues, just thought i'd share my experience with you all.

Did you put a new head gasket in when you reassembled? If so, do you have the old head gasket still around?

 

[Wade]

Yup.... I did replace the head gasket on that particular rebuild.... I also replaced it other times on other works for bearing change outs, valve job or timing chain etc.. (we actually opened up this engine quite a few times for service since i got the bike, I'm sure it has been torn down at least or 8 times since 07). If I still have them around, not sure if i could tell which gasket was from that rebuild though. We actually had to tear it down agin since that rebuild..... turned out that some teeth were torn off the clutch basket. Anyhow, sounds like you may have wanted me to check something...?

 

[OlderHuskyRider]

Yup.... I did replace the head gasket on that particular rebuild.... I also replaced it other times on other works for bearing change outs, valve job or timing chain etc.. (we actually opened up this engine quite a few times for service since i got the bike, I'm sure it has been torn down at least or 8 times since 07). If I still have them around, not sure if i could tell which gasket was from that rebuild though. We actually had to tear it down agin since that rebuild..... turned out that some teeth were torn off the clutch basket. Anyhow, sounds like you may have wanted me to check something...?

When my bike ran hot, it turned out to be a leaking head gasket. If a head bolt gets a little loose, it will compromise the HG and create a weak spot where heat from combustion will transfer into the rads.

 

[Wade]

Okay..... Understood. Don't think it was that this time but will keep that tip in mind for future.

 

[OlderHuskyRider]

...... i sent the cylinder to rebuild by Halls.....

Once we put back in the rebuilt cylinder with piston and the Y hose connector, both the clutch and overheating issues have gone away.

What is involved with "rebuilding" a cylinder and do you believe that the cylinder rebuild is what cured your overheating?

 

[Wade]

I'm not sure if I used the correct terminology, however the rebuild was resurfacing the inside of the cylinder as far as i can tell. I had some scorching marks/lines and what i read was that this one fellow discovered that his cylinder block became so thin that it became porous and was allowing superheated gases into the cooling system.... so since there is no sleeve to resleeve, I sent it off to Jeff at Hall's Husqvarna to resurface. I did engrave the outer cylinder so i know it was the same one i got back.
I sure do believe that the rebuild had a big part to play as well as the Y hose connector. With the original T hose connector i believe that the water pump and cooling system was favoring one radiator only (left side) and that was the side that did not have a fan that i could mount. The left side radiator was always scorching hot to the touch whilst the right side was usually much cooler to the touch. This was when testing before boilover of course.....