I just bought a Aasco Pro MX 90 from Eastside MS for my daughter and the first time she rode it it overheated. It is a two stroke water cooled for those that are not familiar with the bike. I put more fluid in and opened the bleeder at the top of the cylynder to make sure it did not have any air pockets in it. That seemed to help a bit, as it took a lot longer for it to get hot and for the temp light to come on this time. My next step is to try and bleed it again. Any other suggestions?? What else would cause this? She was riding in the sand at Glamis if that makes a difference.

Other than that the bike runs awesome and the suspension seams to work very well.

Thank you in advance for your help,

Matt

 

It could be running lean. Have you checked the plug color?

 

I have not checked that yet. I will check that in the morning and let you know. The quad came from Mesa, AZ and I was running it at Glamis. I don't know what the altitude is in Mesa, AZ, but I think it is a few thousand different.

 

Checked the plug today and it is mostly black, so I don't think lean is the problem. What next?

 

If you can, check the plug color at all throttle ranges. This is done by:
- Drive 200+ yards at 1/4 throttle, hit the kill switch and let it coast to a full stop without letting off on the gas. Then, check the plug color.
- Drive 300+ yards at 1/2 throttle, hit the kill switch and let it coast to a full stop without letting off on the gas. Then, check the plug color.
- Drive 400+ yards at 3/4 throttle, hit the kill switch and let it coast to a full stop without letting off on the gas. Then, check the plug color.
- Drive 500+ yards at full throttle, hit the kill switch and let it coast to a full stop without letting off on the gas. Then, check the plug color.
For each plug reading, it should be dark brown to slight black. For more details, surf bottom pictures of:
http://www.dansmc.com/Spark_Plugs/Sp...s_catalog.html

If wondering, your pilot jet could be set great but your main jet could be too lean. If your young rider goes fron 1/4 to full throttle punches, the gas mixture will be lean when going above 1/2 throttle. Thus, over heat spikes above 1/2 throttle that appears in its liquid cooling system. But if you check the plug by simply looking at it (after a normal 30 minute ride), you could be accidentally be reading its color in the before 1/2 throttle state.

For reading plugs, its always best to use a new plug. If you can, also run a lower heat plug in hotter weather and/or at the higher altitude riding locations. An NGK plug with an "8" in its codes. This cooler plug helps keep the engine cooler as well. Also, avoid using a "P" (for protruding tip) plug when your young rider consistantly rides above 1/4 throttle. A non-protruding plug runs cooler as well.

If possible, always use proper antifreeze fluid in the cooling system. It takes the "heat" much better then simply adding more water to the cooling system. This is true for autos and tractors.

Also, is the thermostate and/or water pump on your liquid cooled mini working properly? I'm not too sure how to check it on a liquid cooled 2 stroke mini.

Hope this helps as well....

.

 

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I forgot to mention.....

Once should "re-check their plug color" and if necessary "re-adjust the carb's jet settings" based on where they plan to ride it, not where they plan to adjust it. In other words, re-check and adjust if 500+ feet lower and 500+ feet higher then their current "garage location". Also check and re-adjust based on weather conditions. Dramatic weather changes also has a huge impact on jetting as well....

If wondering, I run a summer jet and a winter jet in my son's Pred-90. The summer Main Jet is good for 40 - 75 degree environment and its larger winter Main Jet is good for 20 to 40 degree environment. For perfect plug color in each range, I move the position of the C-Clip on its Main Needle. A pain in the tail but as many will vouch, these 2 strokes are much more sensitive to altitude and weather changes (compared to a 4 stroke).

Hope this helps as well....

.

 

Two suggestions. First, get Engine Ice. It's expensive but it seems to work. I ride in Florida and we've already seen 94 degrees and the humidity is always high; no overheating yet. Second, if you were riding at Glamis, you have to make sure the bike is moving. If you tried riding with the Holeshots, you were probably digging trenches more than moving forward. Get some paddles so the bike moves. No move, no air, overheat. This quad is liquid cooled but there is no fan. If you were running paddles then you might try retrofitting an electric fan to help out the cooling issue. Check with Scott at West Coast Quads (formerly Eastside, where you probably bought the bike). Those guys said they are looking for a supplier to outfit and retrofit these with thermostatically controlled electric fans.

 

Thanks for the info,

I was originally running the holeshots then swithched to paddles and it was still overheating, not as bad though. Then we tried engine ice and made sure and bled the system real well. It's a lot better now, but a fan would do the trick. I think you are right, my daughter is just not moving fast enough.

 

Altitude for Mesa AZ is 1,241 feet above sea level