The XT550 Thread: Info, Stories and Mods Inside!

The pick-coils are part of the stator assembly and no one seems to sell those new. If you find out different, please post it here.

Your best bet might be a used one from ebay. Could take awhile to find one there.

I had an intermittent problem on mine once. It turned out that one of the keepers in the plug for the CDI had broken, so that that wire wouldn't make consistent contact. I could have kissed the tech that discovered that! But I didn't. I did make sure the shop owner knew how pleased I was.

Spark plug caps are another culpret.

Spark plug caps? Are these bikes supposed to have caps on the spark plugs?

These bikes came from Yamaha with a resistor type cap that snaps over the spark plug.

I was trying to link a pic for you but my phone is not cooperating. You can buy aftermarket NGK ones cheap. The resitors go in them sometimes.

Then if I am understanding you correctly, the sparkplug should not need the extra little thread-on metal cap that some older bikes needed. i don't think mine ever had one.

You are correct, the threaded part is to be exposed on the stock spark plug boot or cap. Some boots require the larger surface and need the little screw on cap.

As promised I will report on a new programmable CDI for the Early XT's. This will not replace the newer TCI type of igniter with the plugs on the unit.

Mine is being shipped as I write this. It is fully programmable but is plug and play out of the box as it is already programmed with the stock advance. If you wish to customize the advance, set an RPM limit or adjust the minimum starting RPM you will need either a standalone programmer or a USB interface cable and software for windows. Software is included. Programmer or USB cable is optional extra.

Since I did not know when this unit would be available I ordered a Hyperpak from New Zealand because MY 86 XT600 was dead due to no spark. I ordered the hyperpak with the simplest wiring which means no kick stand switch or neutral switch wiring. Most of these old kick stand switches are defective and bypassed anyway so why waste time even wiring them in. I did have to bypass the neutral switch wiring at the cdi plug and move the black ground wire to the CDI black ground wire using female bullet connectors. Very easy and could be cut, twisted together soldered and taped just as well.

I was decidedly nervous when it came time to start the bike. I had pulled the spark plug so I could ground it and watch for a spark while kicking. At first NO spark as I was just using my hand to turn it over. I then kicked it and WOW a big blue spark appeared. Of course it started fairly quickly, but since I had rebuilt the carbs completely, things were a bit balky at first. Once it fired up I let it warm up and set the idle. Now it starts usually on the first kick if warm and second kick if it has been sitting for a day or so.

Next installment will be about the.......wait for it....... scroll down.....V







Zeeltronic PCDI-XT. It is not even listed on the web site yet. Mine is the first production unit serial number 1

Can anyone give me advice on lowering my ride?

I need a solid 2" in the back.

I measured the monoshock at 19" eye to eye...logically I figure replacing it with a 17" unit would work.

Any ideas?

P.S. I'm slowly making my way through this abysmal thread

I think a 2" shorter shock would give you more than 2" of lowering. Measure the shock length while the weight of the bike is on it and again after pulling it down 2" for a more accurate measurement. You might be able to move the mount on the swingarm, which would be far cheaper than a $500 shock.:eek1

After much messing around with engines I am nearly back to 'originals' - apart from one...

My first XT550 came with a 34L bottom end and a 550 (5Y1) barrel/head.

I have aquired a 34K02 barrel and piston which is now fitted to the 34L bottom end. The only head I have now is a 5Y1...

Its hard to find any information on what the differences might be - have found references to an increase in the ex.valve diameter from 30 to 31mm but that's about it, and I think that may apply to later models than the 34L.

Also as the bore size is obviously 3mm bigger would this not create an 'overhang' of 1.5mm all round... or does this not matter?

So my question (finally) is does anyone know whether I can drop the 5Y1 head on the 3K02 cylinder without problems?

Any info much appreciated...

Alex

If you need experimental equipment, I have an original mono shock from a 1983 XT550. You are welcome to it, just pay for the shipping - let me know. I dissolved the mono shock on my bike - went old school

https://lh3.googleusercontent.com/-...I/AAAAAAAAAo4/Bob73Y2-4qk/w480-h360-no/Xt.jpg



He recently got a WR250x and wants to use it as his trail bike. So he swaped the 2000 yz250 front end on the XT with the WRx front end. In the end the XT will be a sumo...

I lost the key to my bike this morning. Which, given I just moved was pretty much inevitable. I'd like to hard wire a switch to it any how.

I took the ignition switch off and noticed a red, brown, blue/red, and 2 black wires. I think the red and brown need to be connected as those are from teh stator or something according to the diagram... which I'm not great at reading. I'm trying to figure out how the other 3 wires hook up.

Does anyone know this info?

Thanks. BTW earlier I had posted a question about putting a drz frontend on, and we were able to do that with no problem at all given a bearing set I ordered off of all balls racing. Disc brakes and a modern front suspension helps a lot!

Made the same Mod to mine. Makes the front end work sooooo much better.

That front tire looks really wide.

So, I order a little carb kit on ebay that held a little surprise. The float valve that came in the kit doesn't work on my '83. Right now, the folks that I ordered it from say that I have a Canadian/Californian version of the XT550. The outfit goes by Vintage Spoke. They say that Canada and California used the same part in their carbs. They also say that they have sold hundreds of these kits with no complaints. Gee, lucky me. Anyways, I thought I would throw a picture up of it and see if anybody else has been through this. The one on the left is theirs. Mine, on the right, has a spring loaded pin. The bottom half seems pretty similar as far as dimensions go.

Weird.

Mine is definitely spring-loaded, no doubt there.

Just an aftermarket imitation. I use OEM only from Yamaha.