# Kawasaki TG24 engine running badly



## spinynorman (Jul 23, 2008)

Hi all,

I was doing some heavy clearance work with my Kawasaki TG24 engined brushcutter yesterday when it stopped suddenly near the end of its second tankfull of fuel that day. There was only a very small amount of fuel left so I refilled but the engine felt harsh when attempting to restart. 

After several pulls the engine started but would only run for a few seconds and would not rev. I removed the carb, plug and muffler cover to check for obvious signs of engine damage but there was nothing visible. I was concerned that I may have over-revved or overheated the engine.

The spark plug central electrode insulator had become detached and was resting on the side electrode. Could the engine have overheated to cause this? I fitted a new plug but this made no difference.

It feels like fuel starvation but I've stripped the carb and found nothing wrong. The fuel is fresh. There seems to be a good spark but could the problem with the plug insulator have caused a short which damaged the coil or capacitor? 

The rings appear intact from a restricted external view but what symptoms would I get if they were broken?


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## 30yearTech (Sep 14, 2006)

Is all of the ceramic insulator still on the spark plug, if some fell off, it may have damaged one of the ports in the cylinder. The only way to tell for sure would be to pull the cylinder off of the crankcase.


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## spinynorman (Jul 23, 2008)

The ceramic insulator appears to be intact. Its base has come loose from the internal surface of the plug body and it can now slide along the central electrode. I've never seen this before and wondered if it could damage the ignition by shorting internally or whether this was just a lesser symptom of overheating which has harmed the piston or cylinder. 

Looks like cylinder off time is getting closer!


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## luckyvision (May 24, 2007)

if you ran it out of fuel (& thus lubrication) at high rpm, you likely scored the cyl. pull the exhaust & check. do a compression test too.

--Lucky


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## spinynorman (Jul 23, 2008)

That seemed like a good possibility. I've just stripped the engine, expecting to find scoring or broken rings sitting in the piston grooves. The two screws which hold the cylinder to the crankcase were very loose. There was a small scuff mark, about a quarter inch long, on the piston but no significant marks on either the piston or cylinder. 

The base gasket was in two pieces so I'm guessing that has been compressing over time to cause the screws to loosen. Hopefully a cheap repair


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## 30yearTech (Sep 14, 2006)

luckyvision said:


> if you ran it out of fuel (& thus lubrication) at high rpm, you likely scored the cyl. pull the exhaust & check. do a compression test too.
> 
> --Lucky


Just because you run a two cycle engine out of fuel, does not mean there will be a significant loss of lubrication, provided the fuel used was properly mixed with oil. All engines lean out and die when they run out of fuel, but this will not cause any damage to the engine, as they are not able to run long enough for this to be a factor.


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## luckyvision (May 24, 2007)

30yearTech said:


> Just because you run a two cycle engine out of fuel, does not mean there will be a significant loss of lubrication, provided the fuel used was properly mixed with oil. All engines lean out and die when they run out of fuel, but this will not cause any damage to the engine, as they are not able to run long enough for this to be a factor.


I've allways felt it was a bad idea to run them dry at higher rpms, but too i base that on learning 2 strokes when engines didn't have chromed cylinders, etc. guess i still follow that principal today, even though it may not apply.

anyway, sounds like you found the problem. :thumbsup:


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