[bryson]

Long story short, I bought this '98 500R with about 24k miles from a friend of mine for a pretty good price. I know that he drove the bike for about 7 months and put (I think) about 1000 miles on it, without doing any maintenance other than adding some chain lube when he first got it. Even though the bike was moderately neglected, I know it wasn't ridden terribly hard. The owner before him drove the bike for about the same amount of time, and also didn't do any maintenance. However, I've been told that the bike was completely serviced before the second previous owner bought it, so probably 2000 miles ago or so.

Anyway, on to the real issue. I bought this bike about 4 days ago, and have only put about 7 miles on the bike. I go to school in Clemson but I have a shop in Charleston where I do a lot of work on my cars, so my plan was to drive the bike some around here, then put it in my roommate's truck to bring back to Charleston to really service the bike well. I was on the highway a few days ago and the engine started to run really strangely. I couldn't hear anything due to my helmet and the wind noise, but by the time I made it to an exit and pulled off, the bike would barely accelerate out of first gear. By the time I limped it back to my apartment complex (luckily I was only about a half-mile away), it wouldn't run. Having read many of the posts on this and other websites, I pulled the carbs and cleaned the entire pilot jet circuit based on the information provided here. The carbs looked really clean, and I could see light through the pilot jets. I cleaned them anyway using a single strand of copper wire and carb cleaner until they were absolutely the prettiest pilot jets a woman could ever desire. I set the mixture screws 2.5 turns out, put the carbs back together and on the bike, and still -- nothing. I pulled a stock plug (which looked fine, by the way) and replaced it with a new plug, then attempted to start the bike a few more times. Then I removed the new plug and it was completely dry. I loosened the drain plugs at the bottom of the carbs and saw that fuel was dripping out, so I know the carbs are getting fuel, but it isn't getting to the motor. The pilot jets and any associated passages are clean as well. Any idea as to what my problem could be?

 

[mycat8urskidoo]

long shot but from what i've gathered from the site the last couple months , maybe your vac line coming off the right plug is either not plugged or the line that goes to the emissions crap is leaking, just a thought, my bike wont run too well or at all sometimes when i have that vac line opened up

 

[bryson]

I'm 99% positive that none of the vacuum lines are messed up. I've had it all off of there, and nothing seemed awry. I'm not at home now, but I'll double check again in a few hours. Anything else you guys can think of to check? I am hesitant to think that the problem is in the carbs, since they looked so good when I took them off and cleaned them yesterday. Even so, I can't argue with the fact that there is fuel in the bowl and (evidently) not in the engine.

 

[fog]

Try cleaning the insides of the plug boots.

FOG

 

[dragknee]

I pulled a stock plug (which looked fine, by the way) and replaced it with a new plug, then attempted to start the bike a few more times. Then I removed the new plug and it was completely dry. I loosened the drain plugs at the bottom of the carbs and saw that fuel was dripping out, so I know the carbs are getting fuel, but it isn't getting to the motor. The pilot jets and any associated passages are clean as well. Any idea as to what my problem could be?

id think if it was getting to the bowl, then it should get to the engine, unless your jets were plugged.

check the fuel level in the bowl, and make sure that is within spec.

other than that, are you sure you're getting a spark?

 

[bryson]

Before I pulled the carbs, I checked for spark by putting a screwdriver in the plug boot and cranking to watch the spark arc from the screwdriver to the bare metal on the cylinders. Since it was good, I replaced the plug (which didn't help), then decided to bite the bullet and pull the carbs and clean everything out. I'm going to go check for spark again, and if it all looks normal I'll check the fuel level in the bowl. I'll also clean out the insides of the plug boots as well, since the engine is covered in grime.

On a side note, I noticed that my ignition module (IIRC) is loose. It's supposed to be held in place by a clamp on either side, but one clamp is just missing. I'm thinking that it may have been bounced around enough to go bad, but the fact that I was seeing spark last time that I checked makes me think otherwise.

I'll report back in a few minutes once I check again for spark. Thanks for all the help -- I REALLY need to get this bike going before exams finish up.

 

[fog]

That Module is fully encapsulated and bullet proof. It would have to broken in half to not work.

FOG

 

[bryson]

Yeah, I don't know why I thought it was the ign. module -- it clearly says something along the lines of "junction box." Anyway, I checked the level in the bowls and it was fine, but I haven't checked for spark again yet. I just wanted to post about the ignition module before someone mentioned my mistake :-[ haha but I guess I wasn't quick enough. I'll post back soon, thanks again.

 

[bryson]

Well, I just checked, and I'm still getting spark at the wire end. I'm a little stumped.

Fuel level in the bowl is good.
The pilot jet circuit is completely clean.
The spark is making it to the plug.

So, either the fuel isn't getting from the carburetor bowl into the engine, the spark isn't making it from the plug boot to the plug, or the engine has no compression :'(

The engine didn't fail suddenly, so I don't think it's a timing chain failure or anything that would have just snapped or broken, like a timing chain or valve. I imagine a valve could have possibly bent, but I don't have a compression tester here in Clemson.

It's really important that I figure this out though. I want to rule out all other possibilities because if the engine does have internal issues, I'm not going to finalize the deal. I haven't signed the title or given up any money, and my friend that I "bought" the bike from said that if it's not something that I want to deal with, he will take the bike back. I would really like to keep the bike, though, so I want to be 100% sure that there isn't any internal engine damage.

 

[fog]

Woah, No compression? How come you forgot to state that little dittY? If that is so then you have Major problems that the least of which is a bent valve.
There is NO repeat NO benign reason for no compression.

FOG

 

[bryson]

Sorry if I was unclear in my previous post, I'm not 100% sure if it has compression or not -- I've been working off of the assumption that it does have compression, and I do believe that it does. I only mentioned compression because it's the only other thing that I can think of, not because I think it's the problem. I still think that the problem is in the carbs.

*edit* to add -- the exhaust pulses during cranking, so that's another reason that I think the compression is fine.

There is NO repeat NO benign reason for no compression.

I know -- that's why I am really trying to exhaust every other possibility before I assume no compression.

 

[jlmay]

you can buy a compression gauge at walmart, cheap quality but will get the job done.

 

[bryson]

I will buy a compression gauge if I must, but I don't think that's the problem.

Update -- I have been working mainly on one cylinder (checking fuel level in bowls, checking for spark), just assuming that if one cylinder is getting fuel and spark, the engine will at least try to run. However, I just checked the other bowl and the level was really low. Will the bowls drain down some if the bike sits for a little while? After checking for spark I went inside to try and do some more research, and I left the key in the ignition (doh!). So, when I checked the other bowl, the bike had been sitting for a little while -- I don't know if that will make a difference, though.

So, I guess that opens up two new questions. The bike doesn't even *try* to start during cranking. Am I wrong to assume that if one cylinder were getting fuel and spark, then the engine would stumble, or maybe even start up and run on that one cylinder? As it is, I've checked the fuel level in the right carb and the spark to the right cylinder's plug, and I'm not getting even the slightest hint that the bike wants to start. Secondly, will the fuel level in the bowl change at all while the bike is sitting? If not, then that is a problem as well (although probably not the biggest problem).


*edit* to add a bit about the fuel level being low. If the petcock on the tank is actuated by vacuum, perhaps the bowl is low because it never opened. When I checked the level in the right bowl, I first pulled the reference from the petcock and sucked on it to get enough vacuum to send fuel to the carbs. Once I saw that it was fine, I pulled the plug wire off and cranked the engine to check for spark. Could this have caused fuel to leave the bowl, but not pulled enough vacuum to open the petcock enough to refill the bowl?

 

[bryson]

I searched, but couldn't come up with an answer to this question. I pulled my tank off, and had a friend hold it while I sucked as hard as I could on the vacuum line leading to the petcock. At first, fuel flowed from the tank, but then it stopped. I continued to try for another minute or so, but then gave up to come in and try to figure out if this is normal behavior for the petcock. I would be really relieved if that was the problem, though I'm still kind of skeptical. I'll keep searching around, but can anyone tell me how to "diagnose" a bad petcock? If it is bad, I would like to be able to take it apart and clean it without having to wait around for a rebuild kit -- has anyone successfully rebuilt (ie: fixed just by cleaning) the petcock without any new parts?

 

[fog]

If you had the vacum line to the petcock connected it will open under cranking weather there is spark or not. But not if the throttles are open as this breaks the vacume in the manifold. and will also prevent fuel from being drawn through the pilot circut. Be sure you throttles are closed.
ANd yes if all conditions are met the engine will start and run on 1 cylinder.

Try putting some fuel directlly into a spark plug hole the try to start it.

FOG

 

[bryson]

Well with regards to the fuel petcock, I think that we were holding the tank at an angle or something. I made sure we had it level, and the petcock was fine (yet another stupid mistake). Just to be safe, I set it to reserve and hooked everything back up, tightened a few hose clamps, and jumped the bike off of my car battery and it started. It only idles when choked (and it does so at 2-4k RPM), and it sounds like it's missing. I can't tell if it's lean or rich, though. The fact that adding fuel via choke makes the bike idle better seems like the mixture is too lean, but I backed the mixture screws out about 1.5 turns from the initial 2.5, and the idle didn't improve. I'm going back out to check the level in both bowls again, and I'll go ahead and check the new plug to see how it looks (I'll put a new plug in the left cylinder also). The plug should tell me if it's rich or lean. Also, the bike felt as if it was missing, and I heard some faint popping that sounded almost like an intake backfire -- all of which point to a lean condition.

 

[fog]

It only Idles on choke means the pilot circut is not feeding fuel. #1?

FOG

 

[bryson]

Well, I checked the fuel levels in the bowls again -- right cylinder was fine, the left was really low. Might this be a consequence of the fact that I checked the right bowl first, then checked the left bowl without allowing more fuel to enter the carbs? In other words, would the fuel drawn from the right bowl to check the level affect the level of fluid in the left? Once the drain opens, fuel is let out, the float drops, and existing fuel in the line fills the bowl back up until the float rises. Now, if I move to the other bowl and open the drain to check the fuel level -- there will be no fuel in the line to replace the fuel drawn from the bowl to measure the level.

The more that I think about it, the more I think that the left bowl is just low. The additional volume of the clear hose shouldn't be enough to alter the fuel level significantly and the order in which I check the bowls shouldn't matter. Even if they are connected, the amount of fuel removed when checking the level of the first bowl should easily be replaced (to both bowls, if they're connected) by the existing fuel in the line from the tank.

By the way, I'm pretty sure they aren't connected in any way, so I'm going to try and adjust the floats in the bowls.

 

[bryson]

It only Idles on choke means the pilot circut is not feeding fuel. #1?

FOG

The engine will attempt to idle without the choke, only the idle speed is way too low. If I crack the throttle, it will "idle" really well between 1000-1500 rpm. I'm positive that the pilot circuit is clean.

 

[fog]

Ok just turn up the Idle. The black knob .

FOG