1984 Honda XL600R woes

18 replies to this topic
  • XL600Rguy

Posted June 21, 2005 - 03:32 AM


Hey all,

I just bought an '84 XL600R. I quite like the bike...when it runs :) . It seems to start cold just fine, usually 1-3 kicks and it fires right up. But then if I ride it around a bit (maybe 3-5min or so)then try to ease off the choke it usually stalls and then won't start again til the next day after sitting the night. Is this a lack of knowledge/familiarity on how to start the beast after warm on my part, or is there something wrong with the bike? Im going to try fresh fuel tonite, and maybe some run a little carb cleaner through with it incase one of the fuel lines is a little gummy. Is the carb cleaner a good idea? Should I be running premium or regular gas? If the fresh fuel doesnt work is there anything else i should check? My mechanical skills are minimal. THanks in advance :)

  • Motosprtman

Posted June 21, 2005 - 05:26 AM


Had a new one back in 1987 and thety are much like the new XR650L - lean stock and takes a long time to warm up. Develop a proven strating technique (sounds like you know how to start it). Once started cold go off the choke to the halway point and gently give it throttle to keep it running above idle, in about a minute or two - take the choke off completely continue warming with slight throttle if it will not idle, it should idle at this point - but still prone to stalling until completely warm. when you feel heat coming off of the motor and can smell it :-) becoming warm it is ready to ride. Always use 92 octane gas -premium quality Chevron - Shell etc. Change the oil and use Castrol 20-50W (my preference) and keep the air filter clean and it will run forever. Install a new spark plug too for now - to ensure you don't have a fouled one in there. The color of the (used) spark plug center electrode should be light tan if all is well and running right within the engine.

  • XL600Rguy

Posted June 21, 2005 - 06:21 AM


Ok thanks for the advice, will give all that a try. If it does happen to stall is there a way of starting it back up again after being slightly warm? The previous owner said that if its flooded (not sure thats the prob) you can give it throttle as you kick it but it will kick back. Im not sure I like the idea of breaking my leg / being thrown over the handlebars. If I got it properly jetted would that solve a lot of my problems? It does have a Supertrapp muffler on it, and was not rejetted accordingly as the previous owner said it worked just fine with the stock jetting. As well there are two leaks. One just behind the front sprocket and the cam adjust plug thing on the rh side of the motor leaks too. Are these expensive fixes? I'm looking to get the bike street legal as soon as possible and want it to be reliable for long rides. Any other suggestions? Thanks so much in advance this site is great :)

  • Motosprtman

Posted June 21, 2005 - 11:03 AM


Warm / hot restart - procedure (flooded) is to open the throttle all the way and also hold in the decompression lever and kick the bike thru several times 4-5 at least. This helps to clear the cylinder of excess fuel. If it is REALLY flooded bad - you will smell fuel - at this pointit is best to remove the plug and do as described above to purge the cylinder completely. After you have purged it with 5 or 6 kicks throttle wide open and decompression lever pulled in, then try a normal hot restart - should light off...

Make sure your not just seeing black goo (chain lube) dripping from the countersprocket area (normal on a well lubed chain). If not could be the shaft seal is leaking. the other leak I am pretty certain is a O-ring in need of replacement.

This site is good - but for all things XL try Xlintperformance.com or http://xlboard.aimoo.com/ - I frequent the latter - as I restore the old vintage XL's - I visit here to glean info on my new toy 2005 XR650L.

  • XL600Rguy

Posted June 21, 2005 - 12:27 PM


ok thanks a lot, thats just what I needed to know. I can't thank you enough for your help. After work I'll try out all this stuff and hopefully i can ride my new bike for more then a few minutes. Cheers :)

  • XL600Rguy

Posted June 22, 2005 - 04:27 AM


well i put fresh fuel in it, and tried the warm start stuff. As I was warming it up (as you suggested with the throttle to keep it running) it ran for a bit then stalled, and then using the techniques you mentioned, did fire up again...but would only run for a few seconds...got fewer and fewer then wouldnt start again. Sounds to me like its not getting fuel properly. I'm going to try to get it to a bike shop soon, but in the meantime is there anything else that would be within my abilities that I could try? Im not sure the bike has been run too much as the milage is just over 10K km although it did run fine when i test rode it a couple of weeks ago, and the day after i got it worked fine once it was warm. thanks in advance :)

  • Motosprtman

Posted June 22, 2005 - 05:19 AM


Check that the tank vent is not working crack the cap and let off pressure - if there is alot of pressure then the cap is not venting properly and will stop the fuel flow to the carb. Next - remove the sediment bowl on the fuel petcock and clean it out - while it is off hold a container under it and turn the gas on and check for fuel flow. If that is flowing then onto the carbs. fuel from the tank - thru the petcock - to the carbs - if all ok the next thing is the float needle valve (s) (you have 2 carbs) this requires removeal of the seat and tank and then the carbs. Not a complex procedure for anyone with some mechanical skill. Get a Manual to help you through the procedure. Remove the float bowl (s) and check that the floats move freely and thatthe needle valve (contacts a tab on the float bracket) is also moving freely - if these are sticky it will prevent the carbs from refueling - even if you have good flow from the tank - and thus the bike literally runs outta gas..or cats like it. This is often a symptom or cause as a result of a bike that has been sitting awhile and or has dirty carbs - possibly not thoroughly cleaned when the previous owner got it running to sell it.
The CDI ignition canalso be culprit but I would dismiss it as the biek does start and run - for awhile - if I was a betting man I would think you have a problem in the carbs, float needle valve sticking - main jet dirty etc...

  • XL600Rguy

Posted June 22, 2005 - 06:14 AM


Ok I'll give that stuff a check.

  • GreginFL

Posted June 22, 2005 - 07:53 AM


I had a similar problem where my 1985 XR600 would start and idle, but would stumble if the throttle was cracked open slightly. As the RPM increased it would clean up.

There were 2 problems. The first was that the passages in the left hand carb (the one which has the choke and controls the idle) were varnished closed by old gas. I took the carbs off and cleaned the bowls and ALL of the passages with some cleaner I got from the local NAPA store (best stuff I have ever used for removing varnish) the can said Master Brand. It took 2 itterations on disassembling the carbs and cleaning before the bike ran correctly.

the second problem could have been my doing, I don't know. Both carbs are not identical. The left carb has the choke and a pilot jet in addition the the main jet. The right carb only has the main jet. The float bowls are also different to accomadate the choke passages. As you might have guessed by now they got switched. Make sure the float bowl on the left hand carb has ports in which line up with all of the holes in the bottom of the carb.

I hope this helps.


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  • Mantrasonica

Posted June 22, 2005 - 09:22 AM


It seems to start cold just fine, usually 1-3 kicks and it fires right up. But then if I ride it around a bit (maybe 3-5min or so)then try to ease off the choke it usually stalls and then won't start again til the next day after sitting the night.

Why are you riding around with the choke on? You're probably just flooding the thing. Let the bike warm before you ride. I usually let mine run for several minutes before getting on. Full choke to start, to half-choke almost immediately, no choke within a few seconds. I let the bike warm completely before I ride.

Also, if your bike has a trapp and hasn't been jetted this could be adding to your problems.

My 87 has an unmolested airbox with a uni filter, 8 discs in the trapp, 125 main in the primary, 45 slow jet (you might want to go to a 48), 130 in the secondary.

It takes a good 8-10 kicks on a cold Winter morning to start, maybe 5-8 on a warm day.

  • XL600Rguy

Posted June 22, 2005 - 12:30 PM


Did you completely remove the carbs to get at the bowls or did you just leave 'em in and pop the bowls off, clean, and reinstall?

  • Motosprtman

Posted June 22, 2005 - 12:49 PM


Remove the carbs completely to remove the bowls and while they are off clean the carbs too and check the jetting as suggested - to see what is in them now. I agree that usually you have to rejet - when using an aftermarket pipe.

  • Mantrasonica

Posted June 22, 2005 - 01:03 PM


You can remove the bowls with carbs installed if all you are doing is checking jets

  • XL600Rguy

Posted June 23, 2005 - 03:27 AM


Ive been riding around with the choke on because thats the only way it seems to want to run. Last night I let it warm up for quite a while, maybe 10-15 min then rode slowly in first gear for about 30sec (still had to keep the choke on) or so to get my helmet from the house, and left it running when I went in. Just before I could get out the door it stopped, and wouldn't start as usual.
I checked the fuel petcock, and fuel is flowing freely from it. Didn't get into the carbs, as I don't have enough experience to be sure of doing it right. I think the best idea for me is to just get it to a bike shop and hopefully they can get it into rideable shape, and safety it while they are at it.
If I were to get it jetted properly for that pipe, what would that do its running characteristics? Would it change the power? Operating temp? Gas milage? Thanks again everyone for all your help :)

  • Motosprtman

Posted June 23, 2005 - 05:14 AM


If you need the choke to make it run - it is certainly a fuel problem and runninig very lean. A bike shop will do you right and get it running correctly, preferably a HONDA dealership with a KNOWN GOOD service department. Aftermarket pipes add approximately 5% more power - usually at a loss of some bottom end power - however on a Big thumper it is not very notable. Aftermarket pipes can be tuned for even more power - with jetting etc - (uncorking) essentially the motor breathes better - more air in and better flow out. Enrichening the fuel circuit for the pipe usually means a richer mixture and a cooler running engine. Also a louder exhaust note - dependent upon the pipe, discs etc.

  • Mantrasonica

Posted June 23, 2005 - 07:43 AM


Didn't get into the carbs, as I don't have enough experience to be sure of doing it right.

There is a first time for everyone. These carbs are pretty basic anyway.

Turn off the fuel petcock
Place a container under the bike and open the floatbowl drain screws to empty the carbs
remove the four screws from each floatbowl and remove the bowls making sure not to mix-up the bowl for the primary carb with the secondary. You can use a phillips bit and an 8mm box end wrench to reach the screws if you don't have the correct tool.
Clean both bowls spotless, being careful not to damage the o-rings.
Inspect the o-rings for damage
Remove the plastic splash guards from the end of the main jets and set aside
Remove the pin securing the float. The float and needle valve will fall out, so make sure you don't lose anything.
Carefully inspect the float needle for dirt and/or wear. If there is a noticeable ring around the face of either needle, replace it.
Remove the main/primary jets from the pimary carb and the main from the secondary. Each jet will have a number stamped in it these are the jet sizes. Write these numbers down.
Make sure the jets are spotless.
Get some garden variety carb cleaner and spray generously into the under side of each carb. Wash off any that lands on your engine or frame with water as soon as you can being careful not to splash the carbs.

Also, remove the mixture screw from the primary carb (taking note of how many turns out it is currently set at) and inspect for dirt and/or wear. If there is a noticeable ring around the face of the screw, replace it.

It really sounds to me like you have some crud in one or both carbs. If the above does not solve your problem then take it to the dealer...but bring your checkbook.

Hope this helps.


  • XL600Rguy

Posted June 23, 2005 - 09:24 AM


Ok I'll give the carb cleaning a shot. If I'm going to get into them anyway maybe I should just replace the jets with the proper ones for the supertrapp while im at it?
125 main and 45 (or 48?) on the primary carb, 130 in the secodary carb...these are the best choices right?
How do you "uncork" this bike? I've read a little about the uncorking of the XR650s, does it make the same huge performance improvements? Is it going to make my gas mileage really terrible? (this is a consideration as I like going on long rides and its nice to at least have a couple hundred kms range, and I'm not even sure the stock tank and stock jetting will go that far) How about reliablility? Once I get the bike the way I want it, it would be nice to keep it for a long time. Not sure I want the exhaust too much louder as I might explore some public trails and dont want people getting upset and adding to negative publicity about that sort of thing :)
Sometime in the future after I get the motor running properly and decide if its the right bike for me, I was hoping to get black plastics and a large matching gas tank. Any suggestions for these? I am in Ontario Canada so something readily available would be preferable.

  • Mantrasonica

Posted June 23, 2005 - 09:55 AM


125 main and 45 (or 48?) on the primary carb, 130 in the secodary carb...these are the best choices right?

My 87 runs really strong at 1500 to 3500 feet with this jetting. Are they the best? Who knows. My plug is a light tan color as it should be. Probably slightly lean just off idle, but I can live with it.

I have a spare 48 slow jet and a 130 main I can send you. $15 U.S. sound okay with you? PM me with your address. if you're interested. I don't have a 125, you'll have to hit the dealer for that.

Your bike is already uncorked, as it has a trapp on it. LEAVE YOUR AIRBOX ALONE! If it has been drilled, tape the holes closed with several layers of foil tape or get a replacement airbox. Your bike will have plenty of power with this set-up (barring any mechanical issues) and will have better trail manners. Don't forget that your bike is 21 years old. Probably a bit late in the game to be thinking performance mods. Just get the thing running as good as you can and enjoy.


  • XL600Rguy

Posted June 24, 2005 - 12:53 PM


thanks for all the help, I may mess around with the carbs over the weekend or i might just take it to the dealer to fix. The bike has a lot of other stuff wrong with it and all I can do now is get it all fixed, the right way, and then hopefully have a useful, enjoyable machine. If not maybe I'll try to sell it and look for something newer, and cleaner. Hopefully I won't go broke in the process.

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