Hi all,

I have an 82 XJ650J, which I was finally able to get running well enough to ride after removing and cleaning the carburators 3 times. However, I'm still having a problem with getting the bike started and warmed up. In order for the bike to start, I need to have the choke open completely, and it also helps if I hold the throttle open just a little. Usually, the bike will start and rev up to about 4-5k rpms with the throttle open. Now, if I close the throttle, or don't give it any throttle at all when starting, the bike will usually stall, and then take numerous cranks to get started again. Once it is started, and after the bike has run for about 30-60 seconds, I can start to close the choke and the bike will idle but not very smoothly. Sometimes, I can open the throttle and it'll rev up and this seems to help warm the bike up quicker. But, other times when I open the throttle, the bike starts to sputter and stall. All and all, it usually takes about 5 minutes for the bike to really warm up enough to ride, and after that it's nice and smooth, with an idle about 1500 -2000 rpms. I've cleaned just about everything in the carburators, but the only adjustment I haven't made yet is to the mixture screws because there are covers over them that I can't get off. I've read numerous times that they should "pop" off, but I'm not sure how to "pop" them out. Any suggestions for how to get those covers off and/or what else to check regarding getting the bike to start better would be much appreciated. Thanks,

John

Just out of curiosity, what else have you done to the bike? Replaced spark plugs, checked or replaced any fuel filters if equiped, checked if there is a screen or something clogging at the petcock on your tank, etc...etc..? Definately sounds like some possible fuel starvation, and 1500-2000 rpms sounds too high for idle speed. Its not unusual to have to use the choke to get the bike started, but I wouldn't think it would take 5 minutes to warm it up. Have you run any carb cleaner mixed with your gas? I know you said you tore your carbs down and cleaned them but as you'll read in some of the other posts here, its not always easy to get them cleaned and functioning properly. I would try some carb cleaner in your tank and run it some more, before tearing them apart again. However, buy a good quality carb cleaner additive, read the labels, and I wouldn't put the whole bottle in your tank all at once. These are just a few ideas that crossed my mind, I'm by no means a great mechanic, just getting started myself. There are others here that have much better knowledge than I do....

Scott

I've replaced the spark plugs with NGK BP7ES plugs, put in a new battery, and replaced the air filter with a stock yamaha filter. I did pull the petcock and did not notice any blockages. The oil and oil filter have been changed twice. I also drained the old gas, and have since gone thru a couple of tanks of new gas. I did add some(and by some I mean very little, not more than a dixie cups worth) Seafoam directly thru the fuel line to the carburators, but have not added any to the gas tank. Maybe I should try putting in a bottle with a full tank of gas and running it with that for awhile? I know that 1500-2000 rpm is high for the idle speed(it should be about 1050rpm), but if I turn it down much lower, I'm afraid it won't be high enough to keep it idling while it's warming up. It doesn't reach that smooth idle at 1500 rpm until it's warmed up for a few minutes.
One other point, before the bike warms up and reaches a smooth idle, the headlight flickers in intensity somewhat. I have assumed this is because the engine isn't running at peak performance yet, but could it be an indication of something else, such as the alternator brushes gone bad, etc? I'm also going to have someone more experienced check the valve clearances and timing over the winter. Maybe that could help too...thanks again,

John

I know exactly what you're going through. My bike does the same thing. I have to idle mine in the same range to keep it from stalling, and it is about 5 minutes or so before it's rideable. This is because the mixture is off. These bikes don't have a 'choke' per se, but a 'starting enrichment' system. The 'choke' lever does not choke off the air supply to make the mixture richer, what it does is add extra fuel. If you've never replaced the rubber boots that connect the carbs to the cylinder head, they probably look something like mine did..


They just rot and crack with age, and each crack allows extra air that leans out the mixture. These can be had on Ebay for about $100 a set. BUT, you have to be INCREDIBLY careful removing the old ones!!! Chances are, the boots have never been taken off, and the bolts that hold them on have seized to the head. Use plenty of PB Blaster (NOT WD40), let it soak in for several hours with many repeat applications, and give them a few whacks with a wrench (or a zap with a point tip air chisel - but be careful not to destroy the allen head) each time you spray. Even doing that I was not sucessful in getting them out. I managed to snap 5 of the 8 bolts off. If you can get at them with a VERY light impact wrench (and extensions and wobble joints), maybe they'd be easier persuaded to come unglued.



To add insult to injury, my dumb ass tried to get the things out with an EZ-Out. Word of advice - DON'T EVEN THINK ABOUT TRYING IT! It snapped off on the first try. It added an extra $75 to the bill at the machine shop because the head had to be sent to another shop equipped with a laser so they could burn the damn thing out. You can drill out a bolt, but you can't drill out an EZ-Out. If you bust one or more off, don't screw with it, just let a machine shop handle it. I spent a lot of money I didn't have to because I thought I could handle it.


Soooo, back to the point (sorry about the sidetrack, just wanted to let you know what to expect when you replace the things) I JUST got the head back last week, and I hope to get it back together this week. So I don't know if it's gonna completely cure the problem, but it's definitely a start. the carbs also need to be synch'd for the bike to idle correctly. You will also need a top-end gasket kit (head, valve cover, cam chain tunnel) if the head has to be taken off, so plan on about $150-200 for that if you start snapping bolts.

Matt

I just removed mine by drilling a 1/8" hole through the plug, which is about 1/8" to 3/16" thick, then I took my seal puller, which is a minature slide hammer. Installed a sheet metal screw to fit the drilled hole, and popped them right out. but if you don't have such a puller you can thread the screw in just a couple threads and pull them out with a pair of pliers.