The XT600 Thread

[Olas]

Hey pio, welcome, and nice picture! Where is that?

As far as your problem with the bike, to me, it sounds carb related. If you've never taken them (carburetors) out and inspected them then it's probably a good idea to do that now and see what's going on in there. Even if it does not turn out to be the issue at least you'll have that piece of mind when you are far away from home. Plus, i'm guessing since you are at altitude you've just recently started riding the bike more and more since your purchase in January. This may have led to some dormant gunk inside your carburetor to come loose and clog something up. Just a guess. You said when you wack the throttle open it will want to stall out - maybe it's not getting enough fuel through the main jet/too much air for what fuel is being brought in and it's stalling.

If you are pulling the carbs it may be a good idea to flush out the gas tank with a little gasoline then take the petcock off and clean the fuel filters that sit inside of the tank.

Good luck, hope this helps!

[Whorepedo]

Originally Posted by Whorepedo

Sudco had a minimum order so i had to order 4-#50 jets and 4- #52 jets. I'll probably keep one of each, but that leaves 3 of each that i dont need. if anyone wants one let me know.

Sorry folks. I took the bike to the shop today and the jets they ordered were the incorrect size. We wound up having to drill out my stock pilot. Some fine tuning is still needed. We've got the fuel screw out 5 turns. Once it warms up it runs great.

[alexk243]

I just listed my 1995 XT600 for sale on craigslist (Chicago, IL) and ebay. Here are the links:

http://chicago.craigslist.org/nwc/mcy/1186578759.html


Take a look and let me know if you have any questions.

[Zecatfish]

So its not a 600,
Before:


After:

[D.T.]

Originally Posted by pio

Yo! I've been lurking on this thread for a while since January when I bought a 1989 XT600, my first street legal bike. It's been a blast. But I've run across an issue lately that's prompted me to register and make a post about it.

Recently the bike has begun to run poorly and even stall completely when I am putting load on the engine at low RPM. If, for example, I am going up a light grade in 1st gear and shift to 2nd, and I let the RPMs fall below 2000 while letting out the clutch to engage 2nd, the engine will stop firing, and if I don't clutch it again soon *or* let off the throttle, it will die. However the bike idles at ~1200 RPM beautifully.

I've found I can very easily reproduce the problem if I put the bike in gear, apply the brakes to get the RPMs down to 1500-2000 (the engine runs perfectly during this stage), then attempt to throttle the engine back up to higher RPMs (with the gear completely engaged; no clutch). The engine will always run roughly and miss a few times, and it seems that if I give it less gas, it will miss less and rev up to higher RPMs more smoothly than if I give it more gas.

Today, I even observed the bike doing a similar thing when the clutch is completely pulled in and the engine is disengaged from gear; if I pulled the throttle back slowly, the engine reved normally. If I pulled the throttle back very quickly as if I were gunning it, the engine completely stops firing, and does not fire at all until I let off the throttle.

Any time the bike stalls from this problem, and I need to restart it, I end up having to kick it at least 10 times to get it running again, the failed kicks often being accompanied by backfires.

After recent discoveries about the problem I'm thinking that I should service the carburetor (I have yet to adjust it at all on this bike). Does this sound logical to yous guyses?

I live and ride at high altitude, and I'm not sure the bike's been jetted properly for that, but today I rode as high as 7100 feet and as low as 3500 and didn't observe much of a difference.

Some secondary questions that probably aren't related to my main problem: originally, when the problem was first manifesting itself, I thought the problem was electrical, and upon inspecting the electrical I discovered I had one of those "Hyperpak" CDIs from NZ. I also noticed the bike had a resistor spark plug installed, which was not what my Clymer manual suggested, and I tried a non-resistor plug, which didn't seem to make much difference. Does anyone know what if using the aftermarket Hyperpak CDI makes a difference towards which plug I should use? I'm thinking maybe the previous owner had a resistor plug for a reason. Also, my digital multimeter indicates the resistance in the pickup coil and in the ignition coil main circuit (in the spark plug wire) are pretty far out of spec. I haven't verified this with a second multimeter but assuming the readings are correct, should I worry? I observed 230 ohms from the pickup coil when spec is 90-120, and 20-30 kohms on the pickup coil firing circuit when the spec is like 5-8 kohms... was thinking about ordering a replacement ignition coil since you can get the yamaha part for like $70.

...and the obligatory picture:

Too many words, my head hurts.

Anyway, I recently left my choke on a bit (1/4 open) and it ran funny, so I pushed it in. The coasting enrichener diaphram may be bad also. No experience with the hacked CDI but I recently replace the spark plug cap on mine and it's been flawless starting ever since. I got a NGK cap and cut the (short) oem wire and twisted it on. I wouldn't use a resistor plug if it's not in spec to the manual as far as the secondary ohm reading.

[BIG ED XT FAN]

Originally Posted by Zecatfish

So its not a 600,
Before:


After:

So, Hows the stopping now??

[Zecatfish]

Originally Posted by BIG ED XT FAN

So, Hows the stopping now??

I'm not impressed to say the least.
Not sure whats going on there. Maybe the pad material? It honestly doesn't feel different from the old drum. If you get on them hard and pads start to warm up it seems better.
One last note the wear pattern on the rotor is not right. Like its only grabbing the inside 2/3's of the rotor.

Over all the ride is Lots better on the local dirt roads.

[BIG ED XT FAN]

Originally Posted by Zecatfish

I'm not impressed to say the least.
Not sure whats going on there. Maybe the pad material? It honestly doesn't feel different from the old drum. If you get on them hard and pads start to warm up it seems better.
One last note the wear pattern on the rotor is not right. Like its only grabbing the inside 2/3's of the rotor.

Over all the ride is Lots better on the local dirt roads.

Do you have all of the air out of the brake line? Is the disc bend? My friend has a xr 600 and can stand it right on the front wheel!!
The forks have to be worlds better the XT forks!

[pio]

Originally Posted by Olas Altas

Hey pio, welcome, and nice picture! Where is that?

That's Marion Campground in California's Los Padres National Forest. I'm looking North towards Bakersfield and the San Jaoquin Valley.

I pulled out the carb and blew it out with a little compressed air. I determined that I do not have the high-altitude jets, so I'll be ordering a pair of jets for it once I google around for a good place to order them. I put it all back together and didn't really notice any change to my performance, my low RPM cutting out was still around.

I also have a new spark plug to try, maybe I'll throw that in today and go for a little ride.

[zap2504]

I assume you already checked for the dredded (and most usual) carb manifold separation? The rubber separates from the aluminum mounting plate (fastens to the head) letting in lots of extra air and causes symptoms similar to what you've described. Some re-glue theirs together (auto windshield sealant); others just by new ones (I did).

[Greengo]

I purchased an 1984 xt600 3400mi with a bad clutch basket, i won the basket on ebay put it in that all went smooth (i thought it was going to be the hard part). I also ordered a new clarke plastic gas tank since my tank was rusty inside. Then i tried to get the bike to run i took the carb apart cleaned out both jets and the bowl i took apart helper carb the inside was not ripped also cleaned lines between carbs put the bike back together got it to run for a few seconds.I then realized that i forgot to clean the needle seat i took that apart and cleaned there was alot of tiny rust particles in the screen. So i put it back together again the carb didnt seem to want to fill up so i sprayed some carb cleaner into the inlet where the fuel goes in and i got the carb to overflow then i tried to start it and it worked great i was able to run it for a few minutes i even rode it a half block down the street. Then it died it seemed like it was running out of fuel as it was dying i gave it more gas and it did nothing. I just want to ride the bike any help would be cool.

[BIG ED XT FAN]

[quote=Greengo]I purchased an 1984 xt600 3400mi with a bad clutch basket, i won the basket on ebay put it in that all went smooth (i thought it was going to be the hard part). I also ordered a new clarke plastic gas tank since my tank was rusty inside. Then i tried to get the bike to run i took the carb apart cleaned out both jets and the bowl i took apart helper carb the inside was not ripped also cleaned lines between carbs put the bike back together got it to run for a few seconds.I then realized that i forgot to clean the needle seat i took that apart and cleaned there was alot of tiny rust particles in the screen. So i put it back together again the carb didnt seem to want to fill up so i sprayed some carb cleaner into the inlet where the fuel goes in and i got the carb to overflow then i tried to start it and it worked great i was able to run it for a few minutes i even rode it a half block down the street. Then it died it seemed like it was running out of fuel as it was dying i gave it more gas and it did nothing. I just want to ride the bike any help would be cool.[/quot
Make sure the carb is all clean. If the side stand safety switch is hook up, just re- plug it. Try that! XT 600 rider!!

[CR_TurboGuy]

Trying to clean up some of my spares. Have stock tank, middle air guide & side scoops for it. Looking for $175 + shipping for all of them. Tank has a small-ish dent from dropping it on the trailer when I first bought it.

--JOsh

[CR_TurboGuy]

Anyone know of a tank bag that will work with the Acerbis tank?

--JOsh

[pio]

I changed the oil & oil filter in my bike and put in a new spark plug. The bike seemed to behave quite a bit better after that. It was still missing at high speed like a lot of people seem to experience, but it's been doing that since I bought it. The dying at low RPM was a newer thing and it seems to have gone away or at least decreased.