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cursed 2001 XR80r? New everything wont start, pop, nothing....

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I have a 2001 Honda XR80r that I'm getting together for my nephew that has been nothing but problems.  I've heard it start, but run only briefly and now it wont even pop.  I have a new ignition system, spark plug, carb, tank, and it has a blue spark.  I have no clue what's causing it.  I thought it might be the magnet of the flywheel because it was chipped and not too magnetic.  Replaced it with another and still nothing.  It kicks over OK and I heard it run before and it sounded decent, just shut off after a while which prompted me to get a new carb.  I had to kick it like crazy to get it spinning so it would start then, which is why I thought it might be the flywheel magnet.  This is beyond frustrating and I'm beginning to think the little bastard is cursed or something.  Might take it down to the stealership for diagnosis because I'm at my wits end.  Is there anything I'm missing that would keep it from running?  The carb is new, I timed it out and the valves are set OK.  Any help is appreciated.

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If the valves are opening and closing at the correct time, have spark at the correct time, compression, and fuel it will run.  You're going to have to figure out which one is missing.  Have you tried a new plug...........is it getting wet with fuel?  Is it firing at the correct time...........?  What/where did you get for a "new carb".......?  What/where did you get for a "new ignition" system......?

Old School Al

Edited by Old School Al

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When you say "new carb", do you mean new Honda carb or new ebay carb?  If it's an ebay carb just stop there and put the stock one back on.  Pull the pilot and blow compressed air through it, then hold it up to the light and check if you can see through it.  Reinstall and try it again.  And pretty much what OS Al said. 

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Thanks for the replies.  I put the old carb back on, checked all the connections, ground, CDI Box, etc, Bike is Getting nice Blue Spark, plenty of fuel in the tank + original and new carb, put a different plug in, kick it over and nothing.  Not even a pop.  I double checked the valves and rocker arms move a little at TDC and I set them a couple weekends ago.  The ignition system is off ebay and is new and seems OK.  Is there something wierd like a oil level sensor where if it's too high / low it wont start?  I saw on a youtube video about a compression release spring under the cam that kept a xr400? from starting.... I wonder about compression, but it pops my finger off and even low compression should attempt to start, but this bike just kicks over (and over) with nothing.  Not sure about something like a bent valve or something like that because I've heard it start, but maybe only with the starting fluid because it wouldn't keep running and the reason why I bought the new carb. I've worked on lots of things but this little XR80r has got me to my wits end.  I took the pipe off to make sure there wasn't a lizard inside but still nothing.  The bike looks clean and is one of the 'newer' hondas I have (81XR200r, 83xl125s, 73CB350f, 72CL350) but has given me nothing but trouble.  I have another 89XR100 that I'm trying to get together as a spare if I can't get the XR80r running, but it has a broken exhaust stud / bolt that doesn't want to come out (why only 2 I don't know... 3 would at least work if one broke...) Tried 2 nut trick but not enough threads, might try to find a small bolt shaft size extractor.... Anyway, I'm getting miffed at both, but the XR80r has been the worst.  I think the XR100 will start as it's getting good spark too, but who knows at this point. :foul:

Edited by pimpride

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Spray some starting fluid into the carburetor see if it pops at all. If not you have a different problem than fuel. We've always been able to start a bike if it has spark and fuel might not run well but least it'll start, if your not getting anything you're missing something.

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My kx250f did this exact thing after a carb rebuild, and it ended up being the idle knob was improperly adjusted and wouldn't let it start due to no idle. I went to my friends kx250f took his knob counted turns in and turned it back out and put my bikes carb at the same exact turns and it fired first kick and still fires first kick. Something to look into perhaps, just an idea. Not sure if it is your problem entirely. 

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Leaning towards a bent intake valve... I found a thread about a xr80 having a bent valve and it seemed like a similar issue that I'm having.  They say blow air through the spark plug hole to see if it was seating.... I have a feeling this might be my problem because I think it's not letting fuel in and not firing at all.  The idea that it has good spark and doesn't even pop shows it's probably a fuel issue.  I'll read a little more about the valves and I have a lot of XR100 parts and wonder if the valves are the same size between the two.  Anyway, any help is appreciated and I'm still hoping to get it to run.  Thanks!

Sounds like it might be a bent valve or stuck valve in the guide from stale gas.... -->

 

Edited by pimpride

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Well. Is your spark plug wet or dry? That will tell you if it's a fuel issue or not right away rather than doing all that extra work if not needed. 

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If it will blow your finger off the spark plug hole, compression is not the problem for not running!   Valves aren't bent, because with bent valves it wouldn't have compression required to do that!  (And no, a compression tester or leak down test is not needed.)  Also with a bent valve you would have found excessive valve lash.........way too much!  Did I miss your reply on the spark plug being wet or dry.................???  And how exactly, step by step did you check cam timing.....? Nothing cursed on this little engine............just something missing!;)

Old School Al

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Not too sure about compression.  It's little bike and always felt light when kicking it off and not sure about the valves, lash etc, except that there was no intake rocker play when I first set the valves back to spec.  Now they both rock a little when TDC. I'm wondering if a valve is not moving good in the valve seat and wonder if I could use Marvel oil or similar to lube it.  The plug looks pretty dry but smells like gas some.  Nothing has been apart in the top end, flywheel goes on with the notch with all the T - F, etc set correct.  I got it as a project and the bike originally threw a chain and broke the magneto, mount, etc.  Put the new ignition in and it started once with starting fluid (I think) then stopped, but sounded nice and XR like, but stopped running.  Thought it was the carb and got and aftermarket one which usually helps but hasn't cranked at all since.  I'll spray the starter fluid again to see if I can get it at least to turn over and fire but some of it might be blowing by the intake valve enough to start it.  Thanks for the encouragement and I think she will run. 

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Bent valve is rarely the problem. Spray the starting fluid in it if it starts you're fine. If it won't keep running then you have a carburetor fuel issue. This is really simple.

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I've had 2 carbs on it and it has a new tank / petcock with gas... I'll give it a go tomorrow with the starting fluid and see if I can get it to turn over and fire.  I've heard it run, but not for long and I was spraying it with fluid then... Thought it was a carb issue and got the new carb, neither work, old one is installed now.  Rocker cover is off and looks good for timing.  Any way to easily check the valves to see if they are opening and closing?  Thanks for the help, would like to get it going for my nephew but no good deed goes unpunished.... 

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1 hour ago, pimpride said:

I've had 2 carbs on it and it has a new tank / petcock with gas... I'll give it a go tomorrow with the starting fluid and see if I can get it to turn over and fire.  I've heard it run, but not for long and I was spraying it with fluid then... Thought it was a carb issue and got the new carb, neither work, old one is installed now.  Rocker cover is off and looks good for timing.  Any way to easily check the valves to see if they are opening and closing?  Thanks for the help, would like to get it going for my nephew but no good deed goes unpunished.... 

If it did run then it cut off that's a fuel issue. Your carb is most likely not adjusted properly. Pull the manual out read how to adjust fuel screw and idle screw and start with the basics. You can get the manual online for free. Set the fuel screw and idle screw back to stock. Bet you the new one wasn't adjusted at all, or was out of whack for what your bike likes. Two bikes are never the same even if same make model year. 

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I think it migh have skipped on the cam chain... tried setting carb to spec, starting fluid and nothing. Then I looked at the timing again and it's not at the T when top dead center on the flywheel. It's over to the right at a 2.6? Number. I've uploaded a couple pics and maybe you can tell it it skipped a tooth or if the timing is off. First one shows the flywheel at T and the second is where the cam sprocket mark is. Third shows sprocket at top dead center (piston too) and last pic shows flywheel when sprocket at top dead center. 

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Yea, if the T is at the pointer and the O is not at 12 o'clock, then it's off.  Reset it then try it.

 

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14 hours ago, socalxr said:

Yea, if the T is at the pointer and the O is not at 12 o'clock, then it's off.  Reset it then try it.

 

:thinking:  From what I can see isn't it about 1/2 a link retarded (from cam chain wear)..................if you move it a link it will be half a link advanced!  Half a link either way won't keep it from running..............:excuseme:

Old School Al

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6 hours ago, Old School Al said:

:thinking:  From what I can see isn't it about 1/2 a link retarded (from cam chain wear)..................if you move it a link it will be half a link advanced!  Half a link either way won't keep it from running..............:excuseme:

Old School Al

But that translates to maybe 1 Inch on the flywheel making the magnet off the sensor when it is supposed to fire.... before I got the bike the chain came off and broke off the stator sensor mount etc which might have made it skip the cam chain but I'm not sure. Still can't get it to fire at all and the plug firing at the wrong time will cause this. I'll try to line everything up but will need to pull the rocker arms assembly to move the chain forward on the sprocket. I appreciate the help and insights and hope to get it to fire... 🏁

Edited by pimpride
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1 hour ago, pimpride said:

But that translates to maybe 1 Inch on the flywheel making the magnet off the sensor when it is supposed to fire.... before I got the bike the chain came off and broke off the stator sensor mount etc which might have made it skip the cam chain but I'm not sure. Still can't get it to fire at all and the plug firing at the wrong time will cause this. I'll try to line everything up but will need to pull the rocker arms assembly to move the chain forward on the sprocket. I appreciate the help and insights and hope to get it to fire... 🏁

Good luck,  I hope t goes in your favor, and you get her running!

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3 hours ago, pimpride said:

But that translates to maybe 1 Inch on the flywheel making the magnet off the sensor when it is supposed to fire.... before I got the bike the chain came off and broke off the stator sensor mount etc which might have made it skip the cam chain but I'm not sure. Still can't get it to fire at all and the plug firing at the wrong time will cause this. I'll try to line everything up but will need to pull the rocker arms assembly to move the chain forward on the sprocket. I appreciate the help and insights and hope to get it to fire... 🏁

If one full link will put the marks closer go for it......  As I recall you don't need to pull the rockers to move the sprocket a link.  At TDC on compression, back both cam chain tensioners off and take the top sprocket bolts out (turning cam a bit) one at a time.  Then slip the the sprocket off the end of the cam and you should have enough slack to jump the chain a link.  Note on backing off tensioners:  Push the tensioner bow back with a long screwdriver after loosening the lock......then lock it pushed back.  Turn the eccentric tensioner to the loosest position.   It's been awhile since I've been into one of these but I think (not positive) there is just enough room to slip the sprocket off and jump the cam chain as I've described.

Old School Al

Edited by Old School Al
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