I found a paper copy on eBay and should have it in a few days. If anyone needs a page or so I'd be happy to copy it and send it. I may eventually copy the whole thing and make it available. They seem to be very scarce.

Steve

OEM Service Manual 84-87 Xt600
Anyone have a PDF copy of the manual. Prefer USA model but would take any available.

Anyone with a older Xt600 or 550 interested in info on a new CDI coming available soon after testing. Fully adjustable ignition advance curve and adjustable RPM limit if desired.

Steve

Hello Steve,

I take it that you have already searched the stickies on this sub-forum for the service manual you need?

As you no doubt know, the XT600 series of bikes all used basically the same bulletproof engine.

__________________
Triumph Bonneville 800 (2004), Yamaha XT600E (1999), Honda XBR500 (1986).

Yes, I have searched and have not found the exact manual that matches my '86 USA bike. Not a Tenere, just a standard XT600. Much of the TT600 is the same, but I noticed the stator/pickup coil ohm readings are different in some aspects. I am having ignition issues and was trouble shooting the coils using info from my Clymer manual. In particular, Clymer says to measure the pickup coil from the red/white to the green white. The readings were way too high so I measured from the center tap green wire to each end of the coil and it fell within the range. The TT600 OEM manual says to measure from the green to the red/white and green to the green/white so Clymer has it wrong. I have found other errors elsewhere as well.

I like the OEM manual's explanation of the deceleration enrichner circuit. Now it makes sense. I just rebuilt two of the carbs and replaced the diaphram/valve but wondered what it actually did.

I am anxious to get my '86 running to see how it performs with freshly cleaned carbs, float levels correct, valves set, 170 lbs compression and new CDI. Last time it ran late last year, it was very hard to start, backfired often and generally ran poorly. I see now that the original CDI was failing back then and now no spark at all and was most likely the cause of hard starting and backfiring. I went ahead and replaced the intake boots as I've learned here and other forums that they responsible for many ill's since they get hard and leak air. So I guess this was a blessing in disguise forcing me to look hard at everything. Now I should be in very good shape once the New Zealand CDI arrives...

With the age of the bikes of that vintage, I feel the CDI's are a major source of problems even before they fail completely. Since I am an electronics tech by trade, I understand why. CDI stands for Capacitor Discharge Ignition. Capacitors do age and dry out therefore losing capacity and therefore store less charge to dump when triggered into the coil to make spark. Makes sense to me...

All of this points to a need to replace and update the CDI. There are a couple of companies that make replacement CDI's now and a third is adapting an existing fully programmable unit to work with the older Xt's. I will be testing one and can report on how it goes. If anyone is interested in this please PM me anytime.

I'll report here how my New Zealand unit performs as it may help someone else diagnose their problems.

Steve

I have had CDI issues as well with my US '89 XT , I have a spare cdi here but haven't tested it, my bike ran on it. I have an original factory manual, I will never buy a Clymer or Haynes because of the exact reasons (and a few more). Our US stators and pickups are different than the rest of the world I think, I've never seen one that looks like ours and have no idea where to get an actual new one that works. There may be one but nobody has been able to say for sure. You can't return electronics so you'd be out $$$$.

I would like to have an adjustable cdi for it.


My bike would sometimes run fine then suddenly spitter/pop and die. Then it almost broke my ankle due to backfiring.
Right now I have the smallest jets I can find, dropped the needles as far as possible and have the mixture screw turned in tight, plus the nipple on the left intake boot is open to let in air,and it still is running rich(black sooty sparkplug and black carbon in the exhaust. I have rebuilt and cleaned everything 4 or 5 times now, won't lean out.

When you cleaned the carbs, did you remove the jet tube the needle moves up an down in? They(both carbs) have a series of holes that can clog up? Just thought I'd mention that, you probably already know... Other Mikuni carbs have them but have to be driven out and many miss cleaning them. I read thru your thread, has to be very frustrating for you not to mention painful.

I have 2 XT600's an 84 and an 86. All coils check with the manual and I hope I don't have bad trigger coils. That would be a bummer. I can measure AC voltage being generated on the trigger coil, CDI source coil and AC generator coils so I am hopeful a new CDI will solve my "NO SPARK" problem on both bikes.

I will post results of the New Zealand CDI and the one I will be testing for another manufacturer that is fully adjustable. I would think you could set a fairly low value of advance for the starting rpm and hopefully stop any kickback. Let you know.

Steve

The best person I know for this problem is = MEZO (Mark).

He's an Anglo-Saxon / Hungarian helpful Aussie.

Haven't seen him posting here lately though.

Why not try sending him a PM using the forum? Here he is: http://www.horizonsunlimited.com/hubb/members/mezo
I will do it now and ask him to impart his excellent mechanical knowledge of all things XT...

Just sent him a PM.

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Triumph Bonneville 800 (2004), Yamaha XT600E (1999), Honda XBR500 (1986).

Looks like Mezo (Mark) is still pretty active here -

The Ténéré Forum • View forum - The Ténéré Forums

Perhaps you can register on that forum and ask for advice?

I have seen him help a lot of fellow XT riders with difficult (and annoying) problems like this one.

Looks like he still loves the motherland after all.

__________________
Triumph Bonneville 800 (2004), Yamaha XT600E (1999), Honda XBR500 (1986).

I am already a member over there and know about Mezo. As for mine running rich, I've worked on a dozen other bikes and quads, many with Mikuni's so I do know my way around them pretty good. There just doesn't seem to be any thing wrong with them as far as I can find.

At least it quit backfiring now that I briskly kick it over on full choke three or four time, then turn the ignition on and finally give one full hard kick. 98% it starts that first try, then immediately shut the choke off. An adjustable cdi I could set it to 4 or 5 degree advance to kick then go to 28 to 36 depending on what kind of riding I'm going to do.
Less advance=more torque but loss of high rpm,
more advance = less down low torque but good for revving off-road.


One thing that sound weird on the bike is when giving it a good dose of throttle I can really hear that howl coming from the carbs like there is no airbox attached to them, way louder than I've ever heard.

Can anyone measure the diameter of those ports that the needles go through?

I changed every jet with new ones, ran nylon bristles into all ports and did everything possible to find anything clogged, but all passages seem open. The only thing I can think of is a previous owner drilled out some passageway a little bit that I can't tell or that secondary slide (and jet that I can't get) is leaking fuel when it shouldn't. The fact that the mixture screw needs to be completely shut otherwise is sits and stutters from too much fuel, it baffles me why so rich yet it still needs less fuel at idle. Everyone else uses the bigger jets than what I now have. I did get 49.4miles per gallon on a recent trip with it .Don't know what they usually get.

My Raptor carbs are looking to be a pain to mount and I'm not sure I'll go that route so I hope to just plug up one set of jets(pilot and both mains) and re-drill to a smaller size plus get some new needles from the later carbs to make them fit.

PS Mezo may take offence to calling him a barbarian Nah probably not

Maybe previous owner changed the needles?? or the needle clip positions..
If float level is set too high you will run over-rich!

If the previous owner need mess around with the jets, that could also cause your problems..

and JJ..why do you say that fitting the raptor carbs is difficult?
I've fitted them on my XT, if you need any pointers just ask!

One thing with the raptor carbs.. in order for them to fit in the XT intake boots you do have to grind a bit off the front ends so it's actually the intake boots holding it in place and not the metal clamps!

Yep Bacardi you hit it with the boots for the carbs. I saw that I had to either cut the boots id to get rid of the lip that helps hold the carbs inplace or grind the carb to make them fit. I don't care to mod the carbs because they are worth $200 now if I want/need to sell them and $0 if I grind them. I was keeping an eye out for a good used set of boots to modify since the ones have now are new. Add to that the trouble with making some sort of airbox or whatever to get a filter setup. I won't use pods, just don't care for that setup. It's still in limbo. Maybe I need to rethink the pod filter thing.

I do have to watch what modifications I do to this bike because it is registered as a collector/antique (20yrs old + original factory) so it has to stay close to how it came from Yamaha in 1988. I never have to pay yearly registration this way.

As too the other carbs, all the jets I have replaced with brand new ones except the one on the secondary carb, it is unavailable. The needles on my carbs for whatever reason do not have any clip grooves or even a way to adjust up and down, I have yet to see another setup like mine on ebay.
The secondary carb needle is held in place by a set screw and a holder that allows the need to move just a little bit but no way to adjust. I did cobble some small washers to force both needles down about .02" but they weren't designed to do that and they don't have much play anymore for self aligning. That why I said about getting new needles from the newer carbs(with clip positions) and trying to make them fit in my carbs.

The float level I have changed a little everytime I had the carbs out, right now the level is about .300" below parting surface.

The ignition I am speaking of will allow you to set the advance all across the RPM range to what ever you want. I believe it will have the ability to switch between two curves you set so you can just flip a switch to change it on the fly. It will hold more than that but two are readily accessable via switch. This is based on this product for other bikes and should carry this feature as well as it is just an adaptation of an existing product for the two trigger coils on the XT's. I imagine one of the trigger magnet inputs will be ignored and the advance curve derived internally.

You have to think in reverse to understand the operation, Say the 36 degree magnet is used for the trigger, the microprocessor just delays the spark an appropriate amount then fires the coil. So less advance is more delay, more advance is less delay. Advance cannot be more than the 36 degree trigger magnet. There is also a provision to adjust the unit so it is in sync with the flywheel exactly so it KNOWS what degree the flywheel is at when the trigger happens. Very exciting technology. I have a unit on another bike that performs flawlessly.

Steve

That would be great, if it works I may put one on my Honda XL also if available for that bike.

Too get more advance I was thinking a person could slot the mount point for the pickup, say 2-3 degrees since you could adjust the timing, then for 6 degrees at start you'd program 3 degrees so at 36 degrees it would be 39.

I've played some with this advance alteration on a Chevy V8 and degreeing the cam to different advances and testing how the motor ran. It was fun seeing how much a person could change the torque and hp just by altering the advance.
Just a thought, I tend to tinker too much and always wonder "what if I did ....." , but I learn a lot by trying. I like adjustments

Well you could "tinker" all you want with the advance. Make anything you want all across the range with the adjustable.

Steve