Another new guy

[x-man78]

Hey everyone,
I m wondering if I can get some people to way in on an issue I m having, I ve just bought a 1981 xs 1100 midnight special. Bike runs great when it s cool out however once it s hot it over heats and shuts down pretty quick. The engine was completely rebuilt in 2009 I ve got 4000 in receipts and the guy I bought it off is pretty solid so is the shop that did the rebuild. They put a 1179 bore kit and I did an oil and filter change the day I got it home, I also put all new plugs and they look good nice n tan. I ride about 200 km a day Monday to Friday. I just can't seem to get it to stop overheating any advice
Thanks
P.S I ve been talking to T.C about this and he has giving me some sound advice just lookin for all possibilities. I also took my air filter and it was soaked in oil and I know I ended up putting and extra half quart or so.

[natemoen]

Welcome!

What do you mean by "it overheads and shuts down"? Does it actually die on you?

If you are getting oil in your airbox then you need to drain some oil out is the crankcase. The oil needs to be checked with the bike sitting vertical and level, preferably on the center stand. Then there are 2 lines on a small view window on the lower rear of the clutch cover on the right side. tge oil needs to be between those 2 marks.

[TopCatGr58]

More background info

Just wanted to add some more info, since I can type quickly!

He says that it can run all day when it's cool outside, but when it's warm, the bike will overheat, and actually stop running. He has to stop and let it sit for 10-15 minutes, but then he's able to restart it with just 1 hit of the starter.

He's NOT touched the carbs, it has OEM exhaust and Airbox. I felt that it sounded like it was jetted a bit too lean, could tolerate it in the cooler atmospheric conditions, but with it being hot outside, the too lean jetting was making it run too hot.

I've mentioned about checking to see what size main jets and pilots, whether the pilot jet screw brass caps are still there or not, and if not, at least turning them out a full turn to start. Stock jetting for the 81 Specials were 110's across. When I did my little big bore kit I put in 117.5 mains, but I also am running Pod filters and a 4-1 set of pipes. But I feel the 81's were jetted too lean for emissions to begin with, and that the big bore kit is requiring a bit more fuel to air ratio than OEM pistons!? He has 2 glass in line fuel filters, NO octopus. He's just a little stouter in weight than my 220lbs, but I felt that really shouldn't be any real contributing factor to the overheating problem vs. possible incorrect jetting.

I mentioned that the dirty air filter could have falsly colored his new plugs due to restriction and oil vapors, and that once he has a new air filter, that he should closely monitor his plugs checking for bleach white coloring which could indicate a too lean condition. I didn't describe the throttle chop procedure.

T.C.

[x-man78]

Hey guys I m liking the input, I just went out for an hour ride stopped a couple times and just let it idle for about 10 minutes and everything was good

[x-man78]

Oh ya I should also add it was8:45 pm when I went so a nice evening ride

[Elwood2]

shot in the dark here but it sounds to me like you have a wire that is bad. when it gets hot isa loses its connectivity from expansion. Then it cools down and contracts completing the circut again.

[x-man78]

Hey Elwood
Just wondering are you thinking something in the regulator or tci ?

[lvrsnr]

forgive me for suggesting it but my GS1100 (second bike) runs completely out of fuel if I push it hard with inline fuel filters in place, could the fuel filters be causing it to run lean and overheat, or shut down for lack of fuel?

[x-man78]

Hey guy's so over the weekend a went on a couple rides that were pretty good I took Monday and Tuesday off so I never ran the bike. This morning I went into work at 6:30 and had a great ride however ride home took me 3 hours to do and hour ride seeing how today is the first day I ve had problems I pulled the plugs the second I got home and T.C they are snow white. So I m goin to pull the tank off and open the carbs as well I m goin to check all my wires and change my fuel lines and filters as the bike sat for awhile. I m sure I ll have plenty of questions threw this process but my first on is for T.C. When I adjust the carbs which way do I make that full turn. Sorry new to do it myself bike work lol

[BA80]

Hmmmm..... kinda sounds like a clogged gas cap vent and not an overheat. try opening the gascap next time and see if that cures it.

You might not want to have a FULL tank when you do that.

[BA80]

I don't really see how ambient temp could affect the cap vent but who knows.

I don't know what TC might have suggested but let me throw a few out too. Working with ambient temps affecting it what comes to mind is, as was suggested, electrical. Ignition switch, kill switch, and tipover switch come immediatly to mind.

I would say to try another TCI but those 4RO units are getting pretty rare.

Just my couple of pennies.

[x-man78]

Hi Greg I tried the gas cap thing TC had suggested that in a pm but the ignition wires and cut off switch are looking like good possibilities I ve checked all the wires under the gas tank and seat n there are bare or cracked wires they all look pretty new actually and are siliconed however as of this morning my cut off switch has started acting up. When I went to start the bike and I switched it to on I got nothing I had to switch on and off a couple times to get it to connect i guess also my signal light aren't blinking anymore when I m stopped only when I rev the throttle or am driving.
Thanks again for the input guys I appreciate all of it.

[trbig]

Fuel starvation is what it sounds like to me. When it's geting fuel, the plugs are fine. On hot days, if you've got fuel lines routed wrong, (Too close to the motor/head) a little bit of a kink, or blockage or narrowing from a filter as mentioned, the gas can start bubbling in the lines. If the lines had slow/low flow to begin with, this could vapor lock the lines. A few minutes of sitting would let the fuel flow again.

Does the bike still have the fuel Octy on it? If so, you might try to eliminate that as a suspect by bypassing it and routing straight fropm the petcock to the fuel "T". Also, before hooking up the lines, get a jug and run the petcocks on to make sure you have a good steady flow, letting the gas run into the jug.

Just guesses here, but thought I'd add mine with the others. I've seen the fuel bubbling pretty good in the inline filter on hot days... but I gotta ask. What are you calling "Hot" that far north?

[x-man78]

Lol hot or us is anything over 28 celcuis/82.4 farnheit, I don t have the oct lines. I have two glass air filters one comming of each petcock. However I was wondering what guys are using for fuel line cause today when it first stalled I checked the gas lines and the fuel line was very soft and when I touched it to give it a little squeeze it disconnected from h engine

[x-man78]

So this is what I'm thinking just to be safe and cover all my bases I m goin to first change the fuel lines and filters, take part and clean cut off switch, as well as adjust my carbs, anything I m missing lol ?