Tips on keeping your GX270 engine running Strong

[Big G Smith]

With the new NasKart Racing Series season beginning soon, I am listing a few tip on keeping your engine at it's peak performane level.

 

1. Be sure to keep fresh valve spring in the head. With RPM's in the 6,600 range it doesn't take long for the valve springs to become week. If they become week, it will cause the valves to float. Best case, this will cause a loss of power and worse case you will bend a valve.

 

2. Always let the engine warm up to at least 220 degrees of head tempeture before you go onto the track. Also do not rev the engine on the stand. This will also cause the valves to float and could cause valve damage. This is what James Matney has done to the #10 engine. He wanted to hear how good it sounded while it was running on the stand with no load on the motor and bent an intake valve.

 

3. Change the oil after every race weekend. These engines are ran hard and they are running at the extreme range of their capabilities. The cost of a quart of oil is a small price to pay for the benifit you will receive. I reccomend using Mobile One 5W40 Turbo Diesel oil. Availible at Pep Boy's.

 

4. Keep a fresh plug in the engine and check the valve lash regularly. In addition, the carb should be taken apart and cleaned after every couple of race weekends.

 

By preforming these few maintenance and service procedures , you will benifit by always having a top preforming NasKart, that will allow you to race the entire season without engine failure.

[CuttingEdgeRacing]

These are good tips, Smitty.

 

I also would like to input a tip:

 

If you are doing your own engine work, I highly recommend removing the head every 3rd race and cleaning the ports, valves and combustion chamber. Since the ports are small any kind of debris or buildup serious restricts flow. RE-lapping valves and cleaning the valve tops is smart also.

 

Also, check for leaking valves, this can be done with some simple rubbing alchohol. After re-assembling the valves, springs and retainers. Pour some of the rubbing alchohol down the port side of the head. See if anything leaks between the valve and the seat OR the seat and the head. Any small amount of leak here is a serious power loss.

 

Installing new valve seats is something that will need to be done by a local machine shop, but is typically inexpensive. When the install new seats, they can be 5 angle cut for better flow.

 

One last bit of information. Porting: I've seen numerous heads with awful port jobs. These motors really require a special port to preform properly. Don't just whale away at the top side of the port without properly shaping the inside of the port. These tricks are a bit of a black art, so sometimes its best to set the die grinder down and pay a bit for some work done right.