Whenever this liquid cooled single gets near max temp on gauge it cuts out. I suspect TCI/CDI (it has both) transistor has thermal protection and inadequate heatsink. Can I get at it to fix that? The bike doesn't like days hotter than 25degC. We get to 40deg C here. What coolant do I need? Dealer says "anything" but I doubt he knows much more than me, and there's no w/s manuals etc online. I do have the 1998 YP259 CD manual, but it's not an exact copy.
LF250T-6B Laguna cutting out?
- Thread starter freddy
- Start date
YP250 thermostat o[ens 80.5 - 83.5 DegC. Can't find specs on Chinese part. My ign unit is 6 wire ,I'm told abt 5cm x 2cm. yp250 coolant is recommended as: Ethylene Glycol/de-ionised water 50/50, without silicates suitable for Aluminium radiators. -I found the drain bolt for the rear gearset. My thermofan switch is set 65.0/61.5 deg C on/off. Fan works ok, will check to see it's not reversed. When the bike is at max temp on gauge it's only abt 80deg C. I haven't tested the sender for accuracy, I don't know what its specs are.
My dealer says this info not available from Lifan. That's just awfully poor. I know, I bought it. I knew what it was and I took the risk. Now I pay the price of buying Chinese crap. No support, no information and no-one to ask. I've seen thermostats from 65deg to 98deg, and temp senders at 25 Ohms @ 80deg to 13 Ohms @ 100deg on the web for similar motors/KW.
My thermostat appears to be 65deg, my fan is set 65deg, and my gauge sender is 14 Ohms at 80 deg. The gauge reads very high on scale at 80deg and when there, my 6 wire DC CDI cuts out until it cools for 5-10min, even if ign still on. Module is in airflow from radiator, above and beside engine.
I could change my sender and thermostat for hotter ones, and use an after market CDI with more cooling. I would not know it that is a valid fix without doing it. The risk is I may damage my engine by overheating it. I have a programmable thermofan switch under the seat, measuring coolant temp in head cross over bleed pipe. It seems accurate enough, 3 sig fig displayed. -20 to 150deg C range,
On >=25deg C days, my motor gets quickly to 80 deg, the gauge is nearly off scale and my ign cuts out after abt 10km. Our summer is >25deg C for >>120days. >=40degC for 20 - 30 days peak.
The 1996-1998 Yamaha YP250 this motor is cloned from has much hotter settings for these parts, according to the w/s CD. It also produces more power, and the radiator has more air.
What am I to do to make this bike ridable for summer, pls? A new ign module is inevitable.
My thermostat appears to be 65deg, my fan is set 65deg, and my gauge sender is 14 Ohms at 80 deg. The gauge reads very high on scale at 80deg and when there, my 6 wire DC CDI cuts out until it cools for 5-10min, even if ign still on. Module is in airflow from radiator, above and beside engine.
I could change my sender and thermostat for hotter ones, and use an after market CDI with more cooling. I would not know it that is a valid fix without doing it. The risk is I may damage my engine by overheating it. I have a programmable thermofan switch under the seat, measuring coolant temp in head cross over bleed pipe. It seems accurate enough, 3 sig fig displayed. -20 to 150deg C range,
On >=25deg C days, my motor gets quickly to 80 deg, the gauge is nearly off scale and my ign cuts out after abt 10km. Our summer is >25deg C for >>120days. >=40degC for 20 - 30 days peak.
The 1996-1998 Yamaha YP250 this motor is cloned from has much hotter settings for these parts, according to the w/s CD. It also produces more power, and the radiator has more air.
What am I to do to make this bike ridable for summer, pls? A new ign module is inevitable.
DohcBikes
Fuck You.
Pardon me if I misunderstood the entire reason for this thread but as I gather from your information, it is already at significant risk of overheating, so what's your point?
The procedure is a matter of tuning. If you don't want to try things in order to gain information there's nothing I can do.
The procedure is a matter of tuning. If you don't want to try things in order to gain information there's nothing I can do.
I want to know what the defaults are with the 3 components listed. Then I'll be able to tell if mine are working properly. If they are, then I can look at reasons why it's overheating. ATM I have no real proof the motor is overheating.. I do not know the normal running temp of the engine, and I have only one accurate measuring instrument. All the rest are unknowns to me.
Logically, it has coolant and a presurized system. So it prob runs at 110degC or so warmed up. If so, my temp gauge sensor is u/s cos it's out of tolerance. Thermostat can possibly be increased to higher opening temp one, as can thermofan. . All logical, sensible theory, BUT does it apply to this engine, or is it a special case? I can't tell, and risking a trail could wreck the motor. I can't afford to lose it, so I'm seeking confirmation that all is well or not first.
freddy said:
This is comprehensively incorrect. Period. The more and faster coolant travels through the radiator, the cooler the total system volume will be. This is elementary physics and Thermodynamics 101. This will be the case regardless of how poorly the radiator is performing or any other cause of too much heat forced into the system. Slowing coolant through the radiator may result in greater energy transfer for that portion of the coolant volume, but not as great as the corresponding increase in energy input from the engine due to the same increase in residence time. The net is a temperature increase. By your logic the engine would run coolest with zero coolant flow. Slow the coolant flow down to zero and the coolant in the radiator will be cooled down to ambient. What do you reckon will happen to the coolant in the engine in the mean time? You could be wasting your time on the electronics without knowing that the mechanical system is working. Prove the water pump is providing adequate flow. Take out the t-stat to take it out of the equation. Determine the system is actually full. If your gauge does not then report a reduction in temp for the same conditions get another way to check the temperature. If it is still getting hot, suspect another likely cause like the radiator, head gasket or ignition timing. Prove all is well with the basics first and work your way up to the more complex.
The response is not linear, and time is necessary to cool the liquid. If liquid too hot at radiator exit then motor temp rises. Thermodynamics do not lie-I know it sounds odd, but it's been well known for many years, moreso on some designs than others. Friend==Google-where you will find both arguements.
DohcBikes
Fuck You.
Which explains why the purpose of a thermostat is to keep the coolant up to temp. If it was not intended to keep the coolant at operating temp, it would not be there.jpmobius said:
When your engine gets hot, do you think the thermostat closes to allow the coolant to pause at the radiator? lol. Nope. When it gets hot, the thermostat opens to allow the maximum flow.
Try running it with the thermostat out for a while. Contrary to your thinking it will not overheat, and will in fact reach minimum operating temp. If it does not stay cool, then you have another issue such as a blockage or air.
A thermostat has a maximum port area to limit the maximum flow rate. Remove it and the area usually increases considerably. There isa maximum rate of heat transfer from the fluid to the air via the radiator Most radiators are minimum practical size.
If heat added by motor is greater than heat lost by cooling then the motor temp rises.
I'm saying there is a maximum heat transfer rate for a given cooling system. If there is not enough time for excess heat to be transferred from the radiator because of excess flow rate, the motor, which was ok before, will overheat. Do the research, study it out. Let the FACTS speak for themselves-then agree with the facts, and you will be right. Opinions are easy liars, facts cannot be disputed. It's a know phenomena. I've seen it happen often enough among the ignorant and the desparate. The hotter the day, the greater the risk.
If heat added by motor is greater than heat lost by cooling then the motor temp rises.
I'm saying there is a maximum heat transfer rate for a given cooling system. If there is not enough time for excess heat to be transferred from the radiator because of excess flow rate, the motor, which was ok before, will overheat. Do the research, study it out. Let the FACTS speak for themselves-then agree with the facts, and you will be right. Opinions are easy liars, facts cannot be disputed. It's a know phenomena. I've seen it happen often enough among the ignorant and the desparate. The hotter the day, the greater the risk.
DohcBikes
Fuck You.
By god for someone that has a Ph.D in cooling you sure don't seem to grasp the basics.
I build water cooled race engines. I'm pretty sure I know how a fucking cooling system works and how to diagnose one as well. You can call Bill Nye the science guy and talk to him all day about your cooling knowledge and it isnt going to fix your issue.
Good luck with your scooter issue.
I build water cooled race engines. I'm pretty sure I know how a fucking cooling system works and how to diagnose one as well. You can call Bill Nye the science guy and talk to him all day about your cooling knowledge and it isnt going to fix your issue.
Good luck with your scooter issue.