Something is getting Hot - Harley Forum

JCourneyaP · #1 08-19-2008, 02:47 AM

Okay- I know this has been asked before but I am too dang tired to try and find the answer.

So I ride for a hour or so. 80 degrees out. 70 to Whatever miles an hour.

Bike is hot. When I stop for gas the damn thing does not wanna start up until it cools down. She turns over. Fires up. Catches for a sec then dies.

It has also stopped dead while sitting in traffic. So what is getting too hot?

If it sits for 15 minutes or so it fires up just fine........

Fenderplayer · #2 08-19-2008, 10:46 AM

Do you have an oil temp guage? How hot does it get? I've had my bike get up to 270 F sitting in traffic jams and not have the problem. Does it only do this when it's hot?

4cams · #3 08-19-2008, 03:05 PM

Quote:

Originally Posted by JCourneyaP

Okay- I know this has been asked before but I am too dang tired to try and find the answer.

So I ride for a hour or so. 80 degrees out. 70 to Whatever miles an hour.

Bike is hot. When I stop for gas the damn thing does not wanna start up until it cools down. She turns over. Fires up. Catches for a sec then dies.

It has also stopped dead while sitting in traffic. So what is getting too hot?

If it sits for 15 minutes or so it fires up just fine........

I'm not sure but after about an hour at high speeds, when it's really hot out, my bike will not idle unless I give her a little throttle and raise the rpms up to about 1100 rpms. It almost feels like the gas is vaporizing or something. I know I'm a wee bit lean cause I'm jetted for 7000 feet. I'm going to richen her up and see if this helps. That's all I can think of to do. If that doesn't fix it, I'll re program the ignition. The last two summers, this never happened.

milindh · #4 08-19-2008, 06:19 PM

Hey Joe

I had an '87 Sportster that would do that if I was in hot weather (over 90 deg). It would start sputtering and then just stop running altogether. So I would pull over to the side of the road and once the engine cooled off a bit, after maybe 15 minutes, it would start right up and run fine. I was sure it was something like a MC vapor lock or plugged gas cap vent but it turned out to be a faulty little heat sensor in the ignition. Sorry I can't remember the name of the part but it was under the derby cover (or whatever you call that cover on a Sportster) and was easy to replace. You can check it with a continuity tester and a heat gun or hair dryer. It may or may not be your problem but I'd at least check it out. I'm betting it's some electronic component that doesn't like heat or has gotten weak with age.

Good Luck Dude

frisco-rigid · #5 08-19-2008, 07:53 PM

Hi JC

A couple times I've described somewhat similar symptoms.. It was always in our AZ summer heat..

One is where I would do 80ish for several miles and right at the bottom of my off-ramp, --only if I got stopped by the light,-- the motor would only sometimes die just as I would take off from that light..
I never had the prob again after I fattened up the idle,,,,BUT, it was quite awhile ago and I do not remember if I simply adjusted it a tad richer or if I changed to a fatter Intermediate jet.. 99% sure it was an S&S G..
Because I never have probs with oil temp even in our heat the oil temp had Nothing to with MY situation..

The other is very similar to yours where, in the summer heat, if we stop for about 10 minutes I will sometimes have to kick 5-6 times to start, but for a very short stop,, or say over 20 minutes, it kicks on the first like usual..

My thoery, and it is only a theory, is that the A/F left in the cylinder and the intake track that would normally fire right off gets evaporated away by the combo of OP temp and extreme summer heat..
So, maybe it doesn't get evaporated away for the very short stop and after the longer stop, perhaps a new cooled down charge gets sucked in and fires with no prob.. Remember---I have NO sensors......
So, if it is not some kinda elect. or sensor prob like Mil offered, it is most likely fuel related and could be close to my descriptions..
That's all I have for ya bud..

clif02 · #6 08-19-2008, 09:44 PM

Mil may have your solution. It sounds like vapor lock to me. I know my bike will often start harder after I run it at say 70 in high heat for a while. I hope you find the problem and its a simple fix. clif

hotrodsporty · #7 08-19-2008, 10:17 PM

I was thinking vapor lock also. My 04 sporty does the same thing to a point. I have found that when I stop for fuel or other for a few minutes I turn the petcock off (carb of course), and this helps, but idiling in traffic that would not help, would it.

JCourneyaP · #8 08-20-2008, 01:03 AM

Thanks all. Yeah it only does it when its hot out and I am running it kinda hard..

Its not a vapor lock. Ruled that out. When I got home this morning I Adjusted the Idle screw to bring up the RPM's a tad and also turned out the slowspeed jet about 1/8 a turn. Today was hotter and I did not die while idiling. However I hesitated and did not shut if off and try and turn it back on to see if it would start hot. Late for work.

Evaporated A/F mixture. Never thought of that. Thats another thing to play with if the above dont work.

Now for electrical piece being affected by the heat. What? Internal? All my wires and such are well away from the motor. Good gaps for the air to move. Huh???

I am running hotter since I took that breather kit off. I also lost some noticable "Seat of th Pants" Power. Time to put it back on I think and run the hose to the ground unless I can come up with a better container to catch the Oil Air Froth that always escaped my last container all over me and the bike.

milindh · #9 08-20-2008, 02:36 AM

Ok Joe

I dug out my FXR manual and there is a section in the electrical troubleshooting section that shows an easy way to check your Cam Position Sensor. That is what went wrong with my Sportster. It is sensitive to heat and will cause the symptoms you call out. The procedure is very simple and easy to do unlike a lot of electrical stuff.

Basically you pull off the outer and inner timing covers from the right side of the engine and then, using a hair dryer you heat up the cam position sensor a bit and see if your engine dies. You can also get some spray can coolant from and electronics supply place (like maybe Radio Shack) and spray it on to see if it fixes the problem. So if heat on the cam position sensor causes the engine to die just replace it. If I recall correctly it wasn't an uncommon problem. Sorry I was so vague in my post. It was 19 years ago.

Good Luck

Wrightturn · #10 08-20-2008, 03:39 AM

Hey Joe,

Sounds like Millindh has it covered. Have had main breakers overheat but that shuts down everything. Not sure if the bank angle sensor is heat sensitive but if it isn`t the cam pos sensor it is a place to go. Do you get a check engine light and possible trouble code ?

When you rmoved the breather kit did you go back to the stock backing plate ? I helped a friend fabricate a new plate for an 06 carb bike to work with the breather kit. Hose goes to an old style filter. Breathers in the rocker boxes needed to be serviced to get rid of most of the oil.