Sir Puma

Well, I don't do forums much. I had, some time ago, posted looking for help on my 82 XJ650 (found another forum that had lots of help). But the carburetors are still giving me loads of trouble. So I decided to get me a new bike. Today I'll be picking up a 2012 FJR1300. It's been a showroom bike since the dealer got it new but since it's older they can't sell it as new. Getting a fair deal on it. I really like the lines and feel but gotta get a trunk bag with back rest for the wife to ride with me. Just thought I'd share the happy news. Keep the shiney side up.

Well then, please accept my most sincere apologies for asking for advice. I'll do my best to not offend you again. Sense of sarcasm optional. And, yes, Ttask, I have a US XJ650J, thanks for pointing me to XJBikes.com, I'll yank their chain for a while now. The problem I thought may have been Coil related turned out to be a lose wire. Go figure. But I'm still having carb/running issues. Lots of popping and spurting while under power, though not at idle. I've got some parts on order and will be going a complete teardown and clean, adjust the floats, then synch the carbs. One thing I hadn't gone over before was the pilot screws. I didn't want to mess with the mixture. But I'll follow the manual and try to fix this thing. Hopefully that'll do it. If not then it's off to the shop. I just don't know how much that would run. Ugh dt502001, I come here to seek advice from people who are way more experienced in motorcycles than I. As I don't have gobs of money to spend at some school to learn the ins and outs, I choose to seek advice from folks who I see as knowledgable in the field. As many riders are forced to work on their own machines I respect their opinions. Sure I don't hang out here and chit chat about all kinds of stuff, but that's because I don't know anyone here and already frequent a dozen other forums and even manage one. I'm also a private business owner/self employed and rarely have time to hang out on forums.

I guess I will have to sharpen up my Google-fu.

    No, what I'm saying is that troubleshooting ignition or carb issues is the same, no matter what type of bike you have. Check this, if not check that, etc. The manual will tell me how to check and what to look for but I didn't have a clue where to start. I'm not a bike mechanic but many on here are and a little advice would be much appreciated. Google netted me squat. But all that is neither here nor there as I think I may have fixed the problem. In preparation to checking the other leg of the coils I motored it onto my front porch with much complaint from the bike. I got it up on it's stand and started again. While pulling the seat the bike just up and cut off, wouldn't start again. While poking around the small fuse panel I found one loose wire that when jiggled would elicit a clicking noise from under the fuel tank (coils?). After playing with it the bike started and ran smooth. Pulled the wire off and bike died, no starter. I tugged on the connector and it came off with ease. So I replaced it and cleaned up the end of the wire. Runs good, for now. All that remains is some longer test runs and keep an eye on it. Had someone replied with a simple, "check your fuse wires and the wires going to the various components" I might have caught it early. I should have thought to check the wires for secure connections.

I live in the Pacific NW. We have two dry months out of the year, the rest of the time we have a varying degree of rain. I did the secondary test on the coils and got the right reading. Now I have to pull the tank and measure the other leads. Then if that is good I'll need to look at the pickup coil. I may have to make a vid of how it runs. I would think anyone with general 4 cylinder motorcycles would be able to help figure this one out. I sorted out #4 not running right (had the two jets in the carb bowl swapped) but now after running fine for a short time it runs like total crap. I may have to resort to taking it to the shop which could run me more than what the bike is worth.

I could really use some help here. What are some quality replacement coils for an 82 XJ650?

Reading through the manual it talks about this kind of issue also being related to ignition. It describes two tests I can do on the ignition coils, testing the resistance between the spark plug wires and between the wires the come from the electrical system. *edit* I'm a dork fish. I'm getting the correct reading (once I set the multimeter on the right setting). Now I need to pull the tank and test the other leads.

More on my diary of doom. It ran a bit rough this morning but once I had been riding a bit it smoothed out. Ran fine this afternoon but at one point I had to get on it to merge with traffic and it started running like crap. RPMs were jumping around and it was sputtering and acting both like it was starving for fuel and missing the firing order. I could sure use some help.

I'm surprized no one commented. Anywho. I went through the #4 carb and I think I had the Pilot jet and Main jet swapped. One has a very tiny hole and the other big. I'm not positive, but having got through it and made sure the bigger hole was on the main jet I just test ran and the exhaust is getting proper hot and when I pull the plug wire the engine loses some power. I hope that was why my engine would ocasionally act like it was starving for fuel.

Ok, this is starting to really bug me. I pulled the carbs off and there's fuel in the intake area. The reason I thought no fuel was getting to the cylinder is that when I pulled the plug wire while it was running, there was no change in RPM or how well it ran. When I pulled #3 it sputtered and stalled.

Ok, oh bike gurus, it's been cool and rainy all spring and into summer and frankly I haven't been riding much. But now that we finally have some sunny warm weather I want to hit the road and my XJ is being a skank. First, I can be out running like a top then it will act all starved for fuel. But when I put it on PRI she'll run OK. So today I pulled the tank and carbs and cleaned them out. Got some bits of rust and stuff out of the tank and cleaned off the filter screens for the fuel cock. Pulled the carbs mostly apart and cleaned out the primary jets and bowls. I run around the block a bit and it runs like crap. While looking it over I discover that #4 exhaust pipe isn't very hot. I clean the plug and check for spark and it's getting plenty. I unscrew the little plug on the bowl for #4 and fuel pisses out. So the carb is getting fuel and the cylinder is getting spark. But the plug is dry and I don't think it's getting fuel from the bowl into the cylinder. My next step is to pull the carbs again and completely break down #4 and clean every part I can pull off. Sadly this will mean I have to sync the carbs again. Anyone got any ideas where to look first?

I think I have my problem licked. Thanks for the tips and suggestions.

I'm having some similar issues with my XJ650J. I have a thread here about it. I've been building a tool to help with synching the carbs. Once I do it all I'll film it and put it up on YT.

Recorded a video this morning of how it runs.

I've gone through my carbs twice to clean them out and didn't see any issues with either the diaphragms or the floats. Haven't played with the prime setting yet.

Couldn't understand a thing that guy said. Nor could I tell exactly what he was doing. However by viewing some of the other videos I'm guessing you want to adjust to have the same vacuum level on each cylinder with the engine hot. But what I don't reallly understand is that if I sync the butterfly valves on the bench to the exact same timing. Do I then adjust them or the mixture screws when doing the dynamic sync? In theory, I could get a dial vacuum gauge, measure each cylinder then work on adjusting. O I could get two so I could synch two cylinders at a time.

I'll test that out and get back to ya.

Well, pairing 34 seemed to help a little, but I still have the issue. Currently, after letting the engine warm up with the choke (it's been getting cold out now) until the idle will purr without it. Then as I gradually ease on the throttle a few RPM at a time (sitting with engine in N) when it gets to about 4K suddenly the engine bogs down, RPM tanks and the engine dies. After I've driven it around for a while, say an hour, I can gradually increase the throttle to over 7k without any hiccups. Before combining the vacuum lines the RPM would tank at about 2-2.5k. In the next few days I'll pull the carbs and clean them out again, but I want to get new needles and such. They may need tuning but I'm really not equipped to deal with that and I certainly don't have the money to take it to the shop and have them work on it.

As I pulled my vacuum line for inspection I got to thinking on a couple things. First I pressurized my hose with about 80-100 PSI and found a couple small pin holes. Then I got to thinking that the original valve is connected only to the cylinder 3 intake for vacuum. I'm wondering if the spring in the aftermarket valve is simply too strong for the vacuum generated at low idle. Since each intake has a vacuum connection I'm going to tie both cylinder 3 and 4 to increase the vacuum and replace the hose with some new hose. I'll test that and see how the low RPM engine control is. This is a major issue for me because as I'm training to be a safety instructor I have to ace the test on my own bike. It's about a total of 8 miles of driving in 1st and 2nd gear at 2-15 mph. So I need to be able to really control that low RPM engine. The course and test are really designed for bikes under 500cc and with my 650 I can't have it hesitating or stalling when I try to put on a tiny bit of throttle at low RPM. I have heard about the various tank treatments and will probably have to settle for one. But they aren't cheap and I'll need to wait for warmer weather. The carb rubbers on the intake side are fine though cyl 1 and 4 rubbers on the airbox side are a little funky. I doubt they would effect the engine. The engine did run fine and smoothly with the old fuel cock in there but then again it was so messed up it was constantly dumping fuel into the carbs. I'll let you all know how things change with new vacuum line and combining two cylinders.

Yes, I oiled the air filter. I didn't touch the mixture screws, only the idle screw. When I first got it running well it would idle at around 2500. Manual says around 1100 for the idle so I tuned it down. Soon as I can get some vacuum line I'm going to try changing that. Trumpetdude, there really isn't enough room to put in an inline, but I do want to do that just as an added filter process as the tank is old and a bit rusty inside. I wish there was a source for new tanks. I would love an aftermarket tank that would hold more fuel, but no one makes any that I've seen.

Air filter is brand new. One of those spendy K&N types that have the metal mesh screen that don't need repacing.

I've fully disassembled and cleaned the carbs twice already. I'll probably do it again in a while but for now the weather is getting rather cold and wet and makes riding no fun. The thing about the "your tank is empty" situation is that it is random as to when it starts to cut out, anwhere from full tank to 1 gallon left. I've also put the fuel valve on prime and let it sit for a few minutes. After that the bike will run fine for a long time. It's been getting better and I'm just wondering if the vacuum valve in the tap just needs to be broke in. The tank is a 3.5 gallon tank and the reserve is supposed to be 1 gallon. The last few times that I've filled the tank after having to put it on reserve I've put in 2.25 gallons.

Ok, so most everything seems to be working well. I'm sure I have my headlight issue fixed (loose wires under the seat) and I've changed a LOT of parts. My current issues is a lack of power or hesitation when the engine is cold. So, from a cold start, no matter what the daily temps are, I need to use the "fuel enrichment" lever to get it to start. But I have to let it run for some time to fully heat up otherwise when I try and go it hesitates and will sometimes die. Even once it's warmed up a little and I don't need the choke anymore for it to run at idle, when I give it a little throttle the engine acts like I cut fuel and it hesitates and wants to die. It's not until after I've driven for at least 20 minutes before it will run fine at low idle and low exceleration. Had a guy at a gas station (petrol service station?) tell me it might be the idle jets sticking. Not sure what that means exactly. Any ideas, gents? I have a new fuel cock but haven't replaced the fuel or vacuum lines. The bike also likes to "run out of gas" when there's still a couple gallons in the tank and shouldn't need to go to reserve. Not sure if it's related or not.

I was about to suggest checking the choke on it. My thinking is with a hot engine and the choke stuck full it won't start, but doubt it would be slow cranking. Glad you go it worked out.

Frame sure looks spiffy. Can't wait to see more progress photos.