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Post by ryan_ott on Nov 9, 2019 10:32:38 GMT -5
Leak test an engine to check the seals. You could use an unlit propane torch or various other fluids but it’s fairly easy to accomplish. 49ccscoot.proboards.com/thread/506/make-2t-leak-tester-waysLC temperatures can vary, especially if your not using a thermostat and the size of the radiator. I’ve seen some as low as 100f or up to 180/190f. AC or LC doesn’t affect compression alone but there are more performance oriented cylinders out there for LC so you can find some with higher compression.
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Post by Zino on Nov 9, 2019 11:06:43 GMT -5
air cooled 150-180 degrees celcius 300-350 degrees farenheight is where I run and jet for . You are right air cooled run lower compression and slightly richer jetting to help with cooling .
The liquid cooled builds are more powerful since they can run higher compression and rpms and perfect jetting. The goal is never go above 90 degrees celcius
pressure testing is best if you are rebuilding from scratch.
A temp gauge is a must in my opinion for a 2 stroke you get used to seeing the same tempature range on your runs if it changes dramatically time for a diagnosis on why it is spiking check exhaust leaks first and then intake leaks .
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Post by Zino on Nov 9, 2019 11:37:32 GMT -5
The air shrouds are there for a reason. They help direct the cooling air flow around the cylinder So removing them would make it run hotter.
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Post by paydem on Nov 9, 2019 12:27:03 GMT -5
The air shrouds are there for a reason. They help direct the cooling air flow around the cylinder So removing them would make it run hotter. No, I'm not talking about removing the shrouds. I'm talking about cutting them. i.ebayimg.com/images/g/0toAAOSwuMZZHZcq/s-l300.jpgSee these shrouds there? If I cut them out, would the engine run cooler?
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Post by Kenho21 on Nov 9, 2019 12:31:20 GMT -5
The air shrouds are there for a reason. They help direct the cooling air flow around the cylinder So removing them would make it run hotter. No, I'm not talking about removing the shrouds. I'm talking about cutting them. i.ebayimg.com/images/g/0toAAOSwuMZZHZcq/s-l300.jpgSee these shrouds there? If I cut them out, would the engine run cooler? I've seen some people cut the blades out from within the circular part to help with airflow, but have never done it myself. Anything further than that, I would not mess with. Like others have said, they're there for a reason.
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Post by ryan_ott on Nov 9, 2019 12:35:51 GMT -5
The intake section on the fan cover I usually cut that out.
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Post by Zino on Nov 9, 2019 13:00:35 GMT -5
You cannot overcome bad jetting or a lean condition by increasing air flow through a larger fan or a cut away shroud . Jetting is over 80% of the cooling factor on the air cooled scoots .
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Post by paydem on Nov 9, 2019 13:06:01 GMT -5
Another question... I've seen a guy do 700km trip all around the way on low 60's c stable on the temperature (Yamaha Aerox LC cooled), is that true? If so, does connecting it in different places can give a false reading?
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Post by Zino on Nov 9, 2019 14:05:18 GMT -5
That is within the range that they run on here . So that would be easy enough to pull off.
Liquid cooled are designed to run under the temp of boiling water .
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Post by aeroxbud on Nov 9, 2019 15:00:21 GMT -5
Another question... I've seen a guy do 700km trip all around the way on low 60's c stable on the temperature (Yamaha Aerox LC cooled), is that true? If so, does connecting it in different places can give a false reading? The temperature sensor is always fitted to the same place in LC cylinders. They are designed to have a sensor screwed into them
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Post by 90GTVert on Nov 11, 2019 9:02:45 GMT -5
Another question... I've seen a guy do 700km trip all around the way on low 60's c stable on the temperature (Yamaha Aerox LC cooled), is that true? If so, does connecting it in different places can give a false reading? Yeah, that's possible. That has been about has hot as mine runs. It was 40F/4.4C one morning and my coolant temp was 95-100F/35-38C. Where the sensor is could throw off the reading. I put the sensor in the head so it should be as hot as it is anywhere. If you ran the sensor on the cool side between the radiator and pump, then you'd see lower temps. IF you had a cylinder head without a provision for a sensor, there are inline sensors that go in an adapter in the hoses. Just make sure you put it on the hot side. There are also sensors that can go in radiator fins, but I'd think they could give you a little lower readings.
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Post by snaker on Nov 11, 2019 12:46:54 GMT -5
I dealt with 2 stroke snowmobile engines over the years, from free air to fan to liquid.
Free airs were the standard at the time when it was realized that 2 strokes could be transformed from smoke chugging turds to some high performance engines. The problem was that more power = more heat. Engine designers kept making the cooling fins larger and larger till it wasn't feasible to go any larger. Free airs are extremely dependent on surrounding air to wick off heat.
Fans come in two general styles: radial (fan blades attached to crankshaft, flywheel and axial (running a drive belt from crank to a fan. I assume most if not all of these engines are radial fans. Fans didn't seem to get pushed too hard with performance because LC showed up and pretty much took over the hot rodding.
Liquids (LC) are the present standard for small engine performance. LC can have more consistent engine temps which allows the designers to run a tighter piston (smaller piston to cylinder clearance). That means more hp = more heat = the need for better cooling. AC cooled engines have more erratic temps = piston and cyl wall expansion vary more = the need for a "looser piston"
Fans have been generally relegated to the smaller, lower powered and cheaper categories. The cooling system on a fan was specifically designed (hopefully) for that configuration. That system isn't just the fan, its every bit of ducting and shrouds. Any modification what so ever could alter the airflow, probably for the worse. If you do some legit R&D (organized testing, time and lots of money) its possible you could improve things. If your just going to hack at things, good luck to ya.
Temp gauges with LC are pretty good at monitoring because the fluid temps are generally consistent throughout. AC temps are much harder to be accurate because it monitors one spot which can be quite different than another spot.
Something that concerns me with these powerplants is actually the machines they're in. One machine may be a wide open frame and the next has the power plant buried in plastic. Seems to be the same cooling design regardless. The engine maker probably doesn't know what the engines are going into. AC engines require a good supply of air (preferably cool air) to supply the fan and plenty of room to vent out the heated air. I would suggest to address the space around the engine and leave the cooling system alone.
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Post by ThaiGyro on Nov 23, 2019 6:15:36 GMT -5
errmkk! What a great name for this site. String that together...errmkk...errmkk...errmkk...Two stroke sounds! Find a temperature guage. Worth the cost. Simple, just a bi-metallic sensor that goes under a head bolt, or spark plug. Here, cost little. US, always inflated, Europe? Do not know. Maybe worse. Did a super fast search on Lazada, here in Thailand: Note the price: 500 Thai Bhat is about 15 Euro. That is for a KOSO, OEM for many bikes. Yes, this one is for water, but the air cooled ones should be cheaper.
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