running problems with a xt600 -88

[Penol777]

hi.

i have a xt600 -88 bike (with a K, xt600K, in my registration papers) the engine is a 2kf, it has kick start only and front and rear disc brakes. (although the rear end is maby changed to a newer model, but not sure)

it was running fine until a few weeks ago. i accelerated out of a crossing and when i reached about 80 km/t it suddenly started to make noises in the exhaust and died. I tried to kick it to start but no luck.

The next day i opened the carburetor and checked the main jets and nozzle. blowed them with compressed air and reinstalled. After a long time with kicking and sweating it ignited but only did a rev or two before it died again. I still thought it was a carburetor problem so i completely disassembled it, inspected and cleaned it. Ensuring every port on the carb. body was open and not clogged. Then reinstalled. No improvement.

So i then started to look at the el. system. since it actually fires but then dies again the kill swithes is working. I tested them seperately with a ohm meter just to be sure. I also checked the spark plug (tried with a new aswell) and lead. Meassured the ign. coil. All good.(new lead and cap aswell) The engine is generating power (got within Clymer manual limits just by kicking). The only problem i could find is the pickup-coil thats integrated with the alternator. The pickup-coil has over doubble amount of resistance as it should. As i understand it, the pickup-coil gives the rest of the ignition system the pulse at the right time to ignite the sparkplug.

a general bike engine knower said that a wery small blue spark indikates a weak spark. That the spark should be bold and be blue-yellow-ish...???

So i think the problem is my pickup coil?

the only thing i can ad to that is that when it rains sometimes it misses and i have to be careful with the throttle to make it home... (that was the reason for changing sparkplug, lead and cap and it did get better)

anyone have a suggestion/meaning to that?

thanx

[aukeboss]

Assuming you have a XT600 from modelyear '87 with CDI, you have the following wires coming from the engine:

- 2 white wires, they are from the alternator - here not relevant, as they just go to the rectifier / regulator and have nothing to do with the ignition
- 1 red, one brown, from the charge coil of the ignition to the CDI - resistance should be 112 - 132 Ohm
- 1 green/white, 1 black/yellow, 1 blue/yellow from the pickup coil.
Between black/yellow and both green/white and blue/yellow you should measure 92 -138 Ohm. Between green/white and blue/yellow you should measure 184 - 276 Ohm. If you measure something close, all is ok.

In all cases, check:
- the wiring, the connectors
- check the earthing of the system
- check the ignition lock
- check the 'safeties': sidestand switch, clutch switch, neutral switch

Good luck!
Auke

[bacardi23]

STOP KICKING!! mine had a broken cam chain! it also bent both intake valves!!!

[bruken]

It's been said before on these pages, but do check the airbox and air intake system is flowing cleanly. I had an XT550 that fooled every mechanic on the route from Cape Town to Lusaka. The bike ran well until 80 and then would misfire like crazy. In the end it was nothing more drastic than the wire mesh guaze supporting the airfilter had corroded ever so slightly inhibiting airflow and causing the second stage carb to flood the bike. Cost of repair $0 to rip it out, cost of fooled mechanic bills....$$$$$$$$