My starter motor on my 2018 klx250s upgraded to 330cc is struggling to start mid ride, usually after slow and technical sections, I guess when it's hot.

Yesterday I couldn't start in the middle of nowhere but was able to bump start and ride to a mechanic.

Now this isn't any ordinary mechanic, let me tell you. This is a Vietnamese scooter mechanic in the middle of nowhere, but I was willing to let him have a look at it anyway as he'd gotten me out of trouble before.

Anyway, he pulled the starter out, opened it up and lubed it up, before reinstalling it. Then the bike wouldn't start. So he tested various wire points before connecting an even bigger battery to the klx battery using leads and was able to start the bike again.

As I had a friend riding with me and promised a solid day's riding, we decided to keep at it for the day, choosing hills for rest spots in case I needed to bump start again.

The bike was able to start with the button although I struggled a little but not too bad. It sounds like the battery is flat and the starter hasn't enough power to crank over. Sometimes there may be a "pshhhhhh" air sound.

So yet to pull the starter out myself to inspect. Wondering if I have to, or it might sound like something else. I just put a new battery in 3 days prior to the ride which another mechanic fitted and tested.

The bike has 18k kms.

The bike is back home and starting instantly without struggle now, so I'm somewhat confused.









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You might check the start button contact. we replaced the handlebars on my sons 09. Throttle and all had to be taken apart to fit on the new bars. When we tried to start it afterwards the bike would turn over slowly but wouldn't start. Battery was fully charged but would only turn over like it had a dead battery. My son tried it and it fired right up, turned out if you pushed the middle of start button it would just roll over but if the outer portion of the button was pushed it fired right up. I guess the contacts must have shifted a bit. Yours maybe corroded a bit. Looks like you're in a more humid climate than we are.

 

How old is the battery on the bike?
Verify that all of the battery cables have no corrosion at terminal ends. That includes the solenoid and the chassis ground.
Aside from the brushes, the motor shouldn't have much wear, so I'd think that the battery may not have sufficient capacity.

 

It was a brand new battery installed 3 days prior. It was doing it on the old battery also

 

I did all this just then and all above terminals are clean. I brushed them just incase.

The chassis ground connects to the engine correct?

 

Will inspect it tomorrow given the chance.

The only other thing I can thing to do is swap starters with my other klx and test if it's the starter next ride.

Yeah, humidity can be extreme, although I try to keep the bike safe from it

 

A voltmeter will be useful in tracking down where you're losing voltage to the motor.
You can test for voltage drop along the circuit path to the relay and starter. The push button is a low current signal to the relay.
That's the best suggestion I can offer at this point.

 

Can this be tested when the bike is turned off?

I recently bought a volt meter, but no idea how to use it lol, nor can I test it a running bike at home with my newborn asleep LMFAO.

 

This has turned out to be a slipping tourqe limiter /starter idler? We welded it today and the bike starts fine again.

I don't know what's caused this issue.