03 tiger cub with kawasaki 23 help please

[tigercat]

Has anyone messed with the fuel solenoid on the bottom of the carb?

That's easy to check. Remove solenoid, there is a plunger that snaps into the main jet of carb. Simply ground body of solenoid and put a battery to the wire. The plunger must pull away. if it's sticking or not working right clean or replace. The bottom solenoids will crap out faster because all the junk in the gas will settle around the bottom of the bowl (or solenoid plunger)

 

[Mad Mackie]

Hi motorman,
Icing the coils may be great way to troubleshoot this engine. the blower housing will need to be removed to get to the coils, but usually an easy job.
This method was recommended to me years ago by a MerCruiser service rep when having spark problems on a new model of inboard/outboard engine.
I do know of coils that have semi-conductors installed, it makes the spark timing much more precise, usually found on high RPM engines. A friend does maintenance on dirt bikes for a racing team. The machines are Spanish made and vintage with very limited parts available. The coils have to be rebuilt and the rebuilder uses a clear epoxy and you can see the semi-conductor thru the epoxy, kinda neat!!!
I'm not sure if small 3,600 RPM engines use this type of coil, but cooling them down may be a good start.
I have replaced coils on a 2000 or so 17 HP Kawasaki on a Toro ZTR and a 2002 or so 19 HP Kawasaki, but I don't remember what make machine. Neither machine had hourmeters, but they were high time machines. Both of these engines would quit while into an hour or so of steady mowing in warm weather. Usually would restart after cooling down for while, but the coils on the 17 HP finally failed. The still were in spec on resistance readings per the original service manual. The new coils had much different primary and secondary resistance readings and I made note in the owners service manual notes.
Both of these machines had excessive dust accumulation under the flywheels, something that I have found often and has affected the charging systems on some.
Mad Mackie in CT

 

[skooter94]

Thanks guys, great ideas. I'm going to throw you for another loop. I should also say I mow on the side after my full time job. I have about 7 yards that I do. So tonight I was mowing mine and my neighbors. It takes me about 2.5 hours to do all of ours. About 2 hrs in I ran out of gas. So after I put gas in it did the usual starting issue. I did notice not much fuel again in the filter, so I was wondering if the fuel solenoid would affect that. I finished mowing and turned it off and tried to start it and nothing. It wouldn't click or anything. I tapped the carb and still nothing. So I put the battery charger on it and went and ate dinner. I left it on for about half a hour. Went back out and again nothing. Even the gauge on the charger didn't move when I turned the key. Don't know if I said or not but I have all the safety switches bypassed to make sure those aren't the problem. So I was ready to give up and I tapped the module, interlock ( below the key with all the wires ) and it fired right up. Has anyone heard of those working intermittently when they get hot? It seemed like it's all sealed so don't know if that can happen or not. Thanks again

 

[motoman]

Mackie, Thanks, I did a little googling and while kind of secret there is consensus that semiconductors have replaced points found in older magneto machines. For those not familiar the points were needed to switch the low voltage to high voltage for the plug (s). Now (me speak) they use a transistor to replace the points inside the "coil." There are a couple other devices in there . Everything is "potted" (molded} together. But the semiconductors do have a heat threshold where they fail. For me (too much heat is the enemy) it is easy to understant failing coils. In a prior life we would test all incoming transistors at hi and low temp to see if they met spec. Heating them while testing would cause some to fail. Then spraying them with coolant would cause them to start working again. Like everything heat resistant transistors can cost more or less depending . Are failures widespread due to even more mfg cost cutting ? Who knows. :confused3:

 

[skooter94]

Hi motorman,
Icing the coils may be great way to troubleshoot this engine. the blower housing will need to be removed to get to the coils, but usually an easy job.
This method was recommended to me years ago by a MerCruiser service rep when having spark problems on a new model of inboard/outboard engine.
I do know of coils that have semi-conductors installed, it makes the spark timing much more precise, usually found on high RPM engines. A friend does maintenance on dirt bikes for a racing team. The machines are Spanish made and vintage with very limited parts available. The coils have to be rebuilt and the rebuilder uses a clear epoxy and you can see the semi-conductor thru the epoxy, kinda neat!!!
I'm not sure if small 3,600 RPM engines use this type of coil, but cooling them down may be a good start.
I have replaced coils on a 2000 or so 17 HP Kawasaki on a Toro ZTR and a 2002 or so 19 HP Kawasaki, but I don't remember what make machine. Neither machine had hourmeters, but they were high time machines. Both of these engines would quit while into an hour or so of steady mowing in warm weather. Usually would restart after cooling down for while, but the coils on the 17 HP finally failed. The still were in spec on resistance readings per the original service manual. The new coils had much different primary and secondary resistance readings and I made note in the owners service manual notes.
Both of these machines had excessive dust accumulation under the flywheels, something that I have found often and has affected the charging systems on some.
Mad Mackie in CT

So I took the carb apart again and the solenoid appeared to be working as it should. I mowed tonight and same thing, cranks for 30-60 seconds and has trouble starting when hot. I saw on another thread s guy with a 19hp was having the same type of problems. The air filter is dirty but could it be anything else? I may wrong but it appears that you can't ajust the float level as it's made out of plastic. Mad Mackie you seem to be very knowledgeable and I really appreciate any info.

 

[TobyU]

When it is hot and not starting....have you pulled the plugs to see if they are wet or dry and if they have good spark?

My guess is you have little to no spark. What plugs are you running? Gap them smaller, about .025-.027 and see if you get hotter spark.

 

[skooter94]

When it is hot and not starting....have you pulled the plugs to see if they are wet or dry and if they have good spark?

My guess is you have little to no spark. What plugs are you running? Gap them smaller, about .025-.027 and see if you get hotter spark.

Thanks, if not do you think it's the plugs or the coils?

 

[skooter94]

So tonight I replaced the plugs and air filter. I will let you know if it helped tomorrow night.

 

[skooter94]

So here's the update. I mowed for about 45 minutes and shut it off and it started right back up. Shut it off again and it fired up. Came home and mowed for about a hour and a half and tried it 3 more times and it started right up everytime. Thanks for all the input and hopefully this will help someone else that might have the same problems.