1987 xt600 (Need Help)

[Renhalt]

First off this bike is new to me so I have never had it running until now. It sat for two years and the tank had a bad kreen job, I addressed that and the tank has been relined with a new petcock. I also went COMPLETELY through the carb and replaced all the gaskets, diaphram, float valve, seat and filter and all the o rings. Im certain its clean, the air screw still needs some tweaking ect. I also checked the valves they'd re dead on .004 and .006, I installed a new airfilter and plug and changed the oil and filter.

Now this is what it's doing and what I have found, I really need your guys input.
First the bike starts fairly easy 1-2 kicks and it seems to idle fine and has no hesitation when I crack it!
The problem is when I put it in gear it starts stumble and miss and wants to stall. If I try and feather it and take off it will go about 20-25 then will pop and crack and dies as if it's running out of gas. Then its extremley hard to start! One thing I did notice is when in gear and it's starts to miss and pop if I shake the bike back and forth it seems to improve!

My first thought was ignition timing and I went to check it, got out my timing light and rpm gauge and removed the two plugs to check it. I kicked it over and oil came out the top inspection whole! allot of oil, now (im not sure but I don't think this side is supposed to have oil in it!? I realize oil is non conductive but I would venture to say there is a bad gasket or the crank seal is shot or the head gasket is leaking between the intake and exhaust!! IDK???

My questions are as follows:
Is there supposed to be oil in the flywheel area? If so, how in the hell you check the timing without getting oil all over the place? If not! Where is it coming from? Is there known issues that others have had?

If it is the crank seal?
Can the crank seal on the stator side be replaced without splitting the case?!!!

And what would be causing it to miss and pop and die when under load in gear?!! Neutral switch? If so, what wire do I cross to eliminate it to rule it out? Or is it the CDI.? What?

I want to add somthing that may be giving me my problems, just need your thoughts.

When I bought the bike the tach was broken, as you know they are next to impossible to find and if you do, you would think they are made of gold. So, I found a guy in AU that sells aftermarket ones that look like oem. I installed it and I don't think the plug is in tune with the stock one. Because, the high beam light is on when it's on low and vise versa. Also the neutral light stays on in gear but the backlight goes out when you put it in gear. I don't know if this would be giving me my problems as I don't know how the neutral light would play into problems? If so, what do I do to fix it?

I'm sorry for being so long winded but wanted to offer as much info as possible.

Please help as if I'm not careful I will have more money in this bike than what it's worth!

PLEASE ADVISE! Any help would be greatly appreciated!

[Renhalt]

Please offer a little more info as the pic you showed really doesnt tell me anything. Is this where the oil in the stator is coming from? Or is this the problem making it miss and pop when in gear? If so, what is needed to fix it? And is it on the clutch side or the stator side where the clutch are is located?

[G600]

Originally Posted by Renhalt

First off this bike is new to me so I have never had it running until now. It sat for two years and the tank had a bad kreen job, I addressed that and the tank has been relined with a new petcock. I also went COMPLETELY through the carb and replaced all the gaskets, diaphram, float valve, seat and filter and all the o rings. Im certain its clean, the air screw still needs some tweaking ect. I also checked the valves they'd re dead on .004 and .006, I installed a new airfilter and plug and changed the oil and filter.

Now this is what it's doing and what I have found, I really need your guys input.
First the bike starts fairly easy 1-2 kicks and it seems to idle fine and has no hesitation when I crack it!
The problem is when I put it in gear it starts stumble and miss and wants to stall. If I try and feather it and take off it will go about 20-25 then will pop and crack and dies as if it's running out of gas. Then its extremley hard to start! One thing I did notice is when in gear and it's starts to miss and pop if I shake the bike back and forth it seems to improve!

My first thought was ignition timing and I went to check it, got out my timing light and rpm gauge and removed the two plugs to check it. I kicked it over and oil came out the top inspection whole! allot of oil, now (im not sure but I don't think this side is supposed to have oil in it!? I realize oil is non conductive but I would venture to say there is a bad gasket or the crank seal is shot or the head gasket is leaking between the intake and exhaust!! IDK???

My questions are as follows:
Is there supposed to be oil in the flywheel area? If so, how in the hell you check the timing without getting oil all over the place? If not! Where is it coming from? Is there known issues that others have had?

Yes, normal. But check out what Mezo wrote.

If it is the crank seal?
Can the crank seal on the stator side be replaced without splitting the case?!!!

No need.

And what would be causing it to miss and pop and die when under load in gear?!! Neutral switch? If so, what wire do I cross to eliminate it to rule it out? Or is it the CDI.? What?

edit: IF you have the EURO CDI, and not the USA version - Disconnect the kill wire from the CDI. It is black/white. The the bike should run no matter if the side stand switch, start switch or any other switch is faulty. The USA verson may work the same, I just don't know


I want to add somthing that may be giving me my problems, just need your thoughts.

I have gone through two CDI's in my 550 (the same ignition as your xt600), your CDI may be failing. But of course it can be something else

When I bought the bike the tach was broken, as you know they are next to impossible to find and if you do, you would think they are made of gold. So, I found a guy in AU that sells aftermarket ones that look like oem. I installed it and I don't think the plug is in tune with the stock one. Because, the high beam light is on when it's on low and vise versa. Also the neutral light stays on in gear but the backlight goes out when you put it in gear. I don't know if this would be giving me my problems as I don't know how the neutral light would play into problems? If so, what do I do to fix it?

If you disconnect the black/white CDI wire the bike should run no matter what. (if the cdi, pickup etc are ok of course)

I'm sorry for being so long winded but wanted to offer as much info as possible.

Please help as if I'm not careful I will have more money in this bike than what it's worth!

PLEASE ADVISE! Any help would be greatly appreciated!

...

[Renhalt]

The valve makes sense to me, the reason I say this is yesterday I changed the oil. I ran the bike and toped it off and it took 2.1-2.1 qts just like the book said. But this morning I checked it again and it took another .5 quarts to put it in the full range. So the valve could be allowing the oil to leak back into the flywheel housing?

[Renhalt]

When you commented on the crank seal, you said NO NEED, does this mean no need to split the cases or no need to change the seal?

[Renhalt]

What would that valve have to do with it not running right in gear? I understand what the valve does but can't see any connection with the problems Im having other than the oil issue. Btw, I just ordered a new one, regardless it will be replaced anyway. I'm just hoping the new side over gasket I just installed comes off in one peice!!!

[steveloomis]

OEM Side cover gaskets don't survive re-use very well. They have some sealant on one side and stick to the cover or engine case. Easily torn. Always order a new one and have a spare in stock for both sides.

As I said on the other forum, if you need electrical info, let me know.

Your problem could be your side stand switch if you have one. Where are you located. Euro bikes don't have the side stand switch but USA models do have it and other country bikes may have it. Bypass it at the bullet connectors. If you don't have a side stand switch or it is already bypassed try disconnecting the black/white kill wire and see if anything changes.

Since this bike uses a CDI and charge coils in the stator, the battery is not needed to run so you can dismiss that as a problem. It is sounding more like a CDI going bad. Check all your connections from the stator and at the cdi /coil area.

Steve

[Renhalt]

I'm in Lexington, KY USA and the side stand has already been addressed. I'm going to go over everything, I have a manual and I am suspecting either the neutral switch or the CDI, I AGREE it's sounding like the CDI. Two questions:
Have you had any experience with the hyper tech CDI's?
And do you know what wires need to be swapped on the tach I got from mike to make all the lights work as they should?

I already emailed ZEELTRONICS about the PCDI-XT but with shipping and the conversion from us dollars it's probably going to be high. So I may have to go with the hyper tech CDI whether I want to or not!

[steveloomis]

Yes, I have 2 each Hyperpak CDI's one is new and unused, the other is only slightly used. About 1 month or so, then I got my Zeel. The Hyperpac are basically like the OEM model and work well. Made in New Zealand, long delivery time. Like 6 weeks.

If interested, pm me or email:steve@airsignal.net. I am in Oklahoma so it is only about 2 days away from you via USPS.

Wiring will only need slight change by adding bullet connectors in place of a plastic connector. I can plug in a hyperpac or a zeel, same connectors.

Don't know about your tach wires, just have to ohm them out and see what does what and swap the wires around, pretty simple. I don't have the diagram for the DT tach. It is just lights. Usually black is ground and brown is +12 volts. Pull out the bulbs and look at wire colors. Maybe the bulbs can swap holes.

Steve

[Renhalt]

I just checked the coils and the pickup coil is over range at 232 so looks like it may be a a new stator

[Renhalt]

Yeah 350-400 us dollars, ouch! I'm calling a friend tomarrow if there is anyone to rewind it he will know. Or with luck he will have one in his attic of gold above his shop! Keeping my fingers crossed! I also emailed a guy in Canada that has one listed but it doesn't say old or new but states he is getting rid of all his Yamaha parts, he want 110.00 us for it. We will see if he even replies, I agree in putting a used one in!

[Renhalt]

G600 pointed out on the other site that maybe I had made a mistake and measured the pickups in series. And Yup that's exactly what my dumbass did, I just rechecked them and it turns out they are both within specs. So it is again looking like a CDI, I still want to rule out the neutral switch though. And I'm also going to run through all the wires and connectors and clean them up and put some dielectric grease on the plugs.

[steveloomis]

Tom,

You probably have the Clymer manual. I have one too. There are other errors in it as well. Nothing beats the factory manual. The Clymer is in error and why you checked the trigger coils in series. The factory yamaha manual has it right but it sounds like you have it figured out anyway.

Another tidbit I learned from the factory manual is how the anti-backfire on deceleration circuit works. The small diaphram on the side of the primary carb is tied to the secondary carb downstream towards the valves. When you close the throttle at high RPM, the vacuum supplied by the little hose running atop the secondary carb to the primary carb pulls the small diaphram in the primary carb and shuts air off to the low speed jet causing a richer mixture. This richer mixture is harder to ignite in the hot exhaust system.

If you have backfire problems, check the intake boots and the diaphram. A replacement kit can be ordered from Yamaha parts that includes all the fiddley parts and the diaphram. Also check the hose for leaks. I found the exact hose in bulk and replaced the hose on both my 86 and 84 carbs. If you need a bit of hose I may have some left over...have to check.

FYI, the screw on the bottom of the primary carb towards the front of the carb is a "FUEL" screw, not an "AIR" screw. Turning it out will richen the mixture with MORE fuel. An "AIR" screw would be on the carb intake side, not the carb output side and is just the opposite. Your 87 XT came with a brass plug that blocks access to the "FUEL" screw. My 86 had never been touched (until now).... many have been removed...

Just a few tidbits that may help others....

Good chat on the phone today....

Steve

[Renhalt]

And yes, I do have a clymer. Does anyone here have a free PDF download of the Yamaha shop manual thy want to share?

[Boardy]

There's a link on the top sticky of this forum.