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Discussion Starter · #1 ·
Hello everyone, I'm new here to the forum and this is my first post! I have a 1982 Honda xl80s that I've had since childhood the I'm in the process of restoring.

I'm having some major trouble getting it to start. I've installed a new coil, points and condenser so far. I have strong spark and fuel to the carb...

The issue is that it's blowing gas out of the air cleaner side! I'm assuming there is something fishy going on with the valve timing or adjustment, however the bike has 600 miles on it and no body has been into it for at least 15 years(it ran flawlessly for 7 years)

So I'm just curious what can possiblity cause an issue like this? I'm a mechanic but motorcycles are pretty new to me. Any input is greatly appreciated!!
 

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Pull and clean the carb(s) Start there, clean the tank and check it for rust. Clean all the fuel lines and any filters.
 

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Discussion Starter · #3 ·
Hey critter thanks for the response! I tried 2 different carburetors with the same result.

Also the tank is pretty rusty, but I soaked it in diesel for a week before putting gas in it. Any tips for getting at that rust in there?
 

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The issue is that it's blowing gas out of the air cleaner side!
Pop the valve cover off, and make sure they are moving correctly, too. If they are sticking, you may just need to squirt some thin oil on them (like Marvel Mystery Oil) and crank it through several times, with the spark plug out to make it easier.

You should search for a service manual, because it appears the two bolts that hold the valve cover on are two of the four head bolts, and you will want the proper torque when you button it back up. Hard to tell from the parts diagrams, though; those bolts could just go into something else on the top.
 

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Discussion Starter · #5 ·
Hey wintrsol thanks for the tip! I'm a mmo believer I'll be putting some in there as you recommended.

I have the service manual on hand but it's for an '85 but if memory serves me correctly they were all the same from 1980ish to 1985.

I'm going to take the valve cover off this evening and see what it all looks like. With the sparkplug out I can see the valves actuating but that's all.
 

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Discussion Starter · #6 ·
Okay sorry for the late update, I've just gotten around to tinkering some more with it.

It starts and runs 1st kick EVERY time now. It had a little lifter tick so I tightened them up to spec .002 according to the manual.

But it bogs.. if I rev it even slightly it bogs and will not rev whatsoever if I hold it at 1/4-1/2 throttle it will backfire through the carb .... The crank key had sheered off which was causing the no start issue...so I made one to perfect size (an actual Honda woodruff is on it's way) and it fired right up but maybe it's still slipping slightly?

I also haven't changed the condenser, does anyone know what symptoms a poor condenser will show?

It does smoke a fair amount for an engine with 880 miles on it. I put a bit of marvel in the gas but not enough to smoke like it does. I also pulled a hose plug on the bottom of the engine and oily sludge rolled out.... Only thing I can think is it's a pcv of some kind since it was a street legal bike.....

Anyone know what the bog/no rev and backfire symptoms could be caused by??? Thanks!
 

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Many things can cause it to bog down when you attempt to rev, from too much or too little gas, a cracked spark plug, a spark plug covered in soot, or weak spark. Since it smokes, you will probably have a dirty plug; put in a new one, and try again.

Condensers fail two ways - open or resistive leak. In the open condition, you get a very thin, blue to purple spark; if it is leaking, the spark will also be weak, but usually orange in color. You can test it with a meter set to Ohms; use a scale like 100 or 200. If the condenser is good, the reading should jump near 0 when you first touch the wire and case with the meter leads, then begin to quickly rise to open. If it doesn't reach open, either it is leaking, or you are touching the meter lead ends. If it never jumps to a low reading, either it is open, or you aren't making good contact.
 

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Wot Wintr said.
I would check the small jets in the carb for blockage. Bog in its simplest terms, is usually too lean in the small jets.

UK
 

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Hello, first post here:

I posted a long post late last night but for some reason it didnt save. I am in the middle of restoring a 81 xl80s, and I came across this thread.

If you seen rust in the tank, chances are that rust is all through your petcock, and carbs. Use this stuff: (cant post links but search Amazon for: Workshop hero wh290487 metal rescue rust remover bath 1gal (WH290487) )
Use this stuff above and let it sit in your tank for some time (follow instructions). When you dump it out, use a strainer (this stuff can be used multiple times before it loses its potency). Grab a small flash light and look inside the tank, if its clean, then youre good to go, if not repeat.

Once you get the rust out of the tank, take the petcock off, I think its a 17mm. This petcock is simple compared to other older vintage ones. Im sure there is rust crud in it. Take it apart, look at the seals and stuff for wear, dry rot. If something looks worn, then do yourself a favor, buy a new petcock. Its actually cheaper to buy a knock-off/reconditioned one VS buying the parts to rebuild it (this isnt usually the case, but for this xl80s, it is). They are cheap...
Once again I cant post links but search EBay: Workshop hero wh290487 metal rescue rust remover bath 1gal (WH290487)

While youre at it, go to your local hardware store and grab some new hoses. Bishes like new hoses. HA kidding!

Now onto the carb. In most cases older carbs can be expensive, but not this one. You can choose to buy a carb rebuild kit, but for the same amount of money, like between 15-30$ you can get a knock off/recondtioned carb. Just make sure you clean the new carb as well. Like a few folks said above, chances are something in the carb(s) you have already is clogged. You could always soak the carb in kerosene overnight, which would help break up some of that rust from the tank that most likely got into there.

One thing I def noticed by buying these recond'd carbs is that the pilot/air screw is NOT where it needs to be.

To be perfectly honest, the Chiltons and other aftermarket manuals do not do justice re: these little 80s. They go over all the models XL like 125, 185 250, etc etc.

Get yourself the official Honda manual. I paid nearly 60$ for mine, but it goes over everything on the little 80s's. (actually it goes over the XR75 motor/bike, which is nearly the same). In the back of said official manual, it goes over each model year's changes from 80-85. Trust me when I say you will be happy with spending this money, if you plan to keep this bike in the family, which I think you said you are.

While youre at it, check the cam chain adjustment. Also check the timing again. I know you said you put new guts in, but not a condenser? Prob should change that out, since you changed the other things out, its not very expensive.

My motor is off getting vapor blasted, so if I come across anything else when reassembling it, Ill let you know. I plan to start a thread once Ive gotten enough post points or whatever this site requires.

Let us know the progress, I know this is a small bike, but a rare bike to see legally on the road again, and thats exactly what I plan to do with mine. Actually I have 2 of them, going to court today to be granted the titles (ownership).

Hope you work out your problems.

-Jack
 

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A hearty welcome to this Forum to both of you new guys.

RK, the hesitation is caused by the intermediate jets being plugged up so do this: Buy some 'Chevron Techron' FI and carb cleaner and pour maybe half a can in the tank and ride it until it cleans everything up! It usually works. If not, the little carb is very easy to clean and repair.

Sam:)
 

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Pull the tank off and clean out that rust. Then start at the tank and clean the fuel system all the way through the carb. Petcock bowl, screens, filters every thing.
 
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