Belizeted 17 Posted July 17, 2022 My Foreman suddenly quit yesterday after running for a short while and wouldn't restart. After several hours, it started up fine and ran for a while. Tried it several days later and the same thing. I realized I hadn't heard the fan for a while, so I disconnected the temperature sensor lead and grounded it and the fan worked. I am weeks away from getting another temp sensor so I tried to run the machine with the fan lead grounded (and running continuously). The machine went a further distance than before but again it just died. Note that when I grounded the lead the temp light stayed on. Realize that it is extremely hot right now in Belize. Question: Is there an overheating safety feature that shuts down the engine if it gets hot (besides the temp sersor)? In addition to replacing the temp sensor, should I consider replacing the oil cooler? Any advice would be appreciated. Share this post Link to post Share on other sites
shadetree 5,977 Posted July 17, 2022 1 hour ago, Belizeted said: My Foreman suddenly quit yesterday after running for a short while and wouldn't restart. After several hours, it started up fine and ran for a while. Tried it several days later and the same thing. I realized I hadn't heard the fan for a while, so I disconnected the temperature sensor lead and grounded it and the fan worked. I am weeks away from getting another temp sensor so I tried to run the machine with the fan lead grounded (and running continuously). The machine went a further distance than before but again it just died. Note that when I grounded the lead the temp light stayed on. Realize that it is extremely hot right now in Belize. Question: Is there an overheating safety feature that shuts down the engine if it gets hot (besides the temp sersor)? In addition to replacing the temp sensor, should I consider replacing the oil cooler? Any advice would be appreciated. we need the FULL make/model name and number, just telling us its a foreman does not cut it. Share this post Link to post Share on other sites
Belizeted 17 Posted July 17, 2022 Sorry. It is a TRX 500 FM 2008. Share this post Link to post Share on other sites
toodeep 1,760 Posted July 17, 2022 Have you checked the vent on the fuel cap to make sure it isn't plugged with anything? Share this post Link to post Share on other sites
Belizeted 17 Posted July 18, 2022 Yes, I checked the fuel cap and it seems clear - I could blow air through it. Share this post Link to post Share on other sites
jeepwm69 7,751 Posted July 18, 2022 18 hours ago, Belizeted said: My Foreman suddenly quit yesterday after running for a short while and wouldn't restart. After several hours, it started up fine and ran for a while. Tried it several days later and the same thing. I realized I hadn't heard the fan for a while, so I disconnected the temperature sensor lead and grounded it and the fan worked. I am weeks away from getting another temp sensor so I tried to run the machine with the fan lead grounded (and running continuously). The machine went a further distance than before but again it just died. Note that when I grounded the lead the temp light stayed on. Realize that it is extremely hot right now in Belize. Question: Is there an overheating safety feature that shuts down the engine if it gets hot (besides the temp sersor)? In addition to replacing the temp sensor, should I consider replacing the oil cooler? Any advice would be appreciated. Wonder if it’s your coil? A dying coil will often stop sparking when it gets hot, and work when it cools off. Pull up the factory service manual in the toolbar at the top of the page, and check the coil now, and again next time the machine dies Share this post Link to post Share on other sites
shadetree 5,977 Posted July 18, 2022 15 hours ago, Belizeted said: Sorry. It is a TRX 500 FM 2008. thank you !,i have seen a few c.d.i's do this..as well as reg/rec or stator fail when hot ?, mostly the c.d.i's do this. also.., i agree with jeep, a bad spark plug coil will do this. Share this post Link to post Share on other sites
Belizeted 17 Posted July 18, 2022 Thanks for the advice. I couldn't find the FSM for my model at the toolbar, but I have a service manual book. However, it says to check the coil with a peak voltage adapter which I don't have. Can this test be done with a multimeter? Share this post Link to post Share on other sites
jeepwm69 7,751 Posted July 18, 2022 https://drive.google.com/drive/folders/1QvEKFzoIUuZ809T18CwVIDToUJfelcG- It's the one all the way to the right, 05-11 Foreman. As for a peak voltage meter vs a multimeter, that's a question for the wire guys. @Melatv and @retro Share this post Link to post Share on other sites
retro 4,074 Posted July 19, 2022 21 hours ago, Belizeted said: However, it says to check the coil with a peak voltage adapter which I don't have. Can this test be done with a multimeter? Generally speaking no, an expensive high end multimeter might be fast enough to capture a high freq AC pulse but most are just too slow. Whenever a test calls for a peak voltage adapter it's best to use the adapter. Share this post Link to post Share on other sites
Belizeted 17 Posted July 19, 2022 OK. Thanks. I guess the down and dirty way to test the coil is to pull the plug and crank it while grounding it on the cylinder head. At any rate, I am going to try to test run the machine this weekend. I am thinking now that I might have had a momentary plug in the gas vent cap. Perhaps I cleared it when I blew through it. When I test run it, if it starts missing before it eventually dies, I will be sure the loosen the gas cap and maybe that way I can isolate this problem. A vapor lock seems to make the most sense. I'll report on the results. Thanks again for the help. Share this post Link to post Share on other sites
Goober 1,555 Posted July 19, 2022 My ignition was not working after a lot of troubleshooting. I would pull the spark plug cap off the coil wire. The cap has a spike that contacts the wire. Look for corrosion—mine was very blue from copper oxidation. I cut off about 3/4 inch to get to clean wire. Used a 22 cal bore brush to clean the plug spike. Applied a thin film of permatex dielectric grease. And reassembled. mine worked after doing this—i had already installed a new OEM CDI Share this post Link to post Share on other sites
Misterclean 420 Posted July 19, 2022 You should check spark immediately after it dies. If it sparks then very quickly spray starter fluid or something flammable in the intake under the air filter.. Share this post Link to post Share on other sites
Belizeted 17 Posted July 19, 2022 Great thanks! I'll check the coil wire connection in the spark plug cap. I'm running in salty conditions so that might be a real possibility! Share this post Link to post Share on other sites
Belizeted 17 Posted July 19, 2022 Question for Goober: Does the spark cap just pull off of the coil/plug wire? I just don't want to wreck anything. Share this post Link to post Share on other sites
Fishfiles 20,147 Posted July 19, 2022 Unscrews —- counter clockwise. Then cut 1/4 inch off end of spark pug wire with a razor knife and reattach it by screwing it back together with some dieletric grease Share this post Link to post Share on other sites
Belizeted 17 Posted July 21, 2022 Well, I managed to service the coil and plug wire, but when I test started the machine the fan did not come on. I had the temp sensor lead grounded. It ran earlier in the week but today - nothing. I tried connecting 12V to the fan motor plug directly and still nothing. Then I checked continuity across the two fan plug connection and it seems the fan is shorted. I checked the fuse for the fan motor and it is fine. I also confirmed that I was getting voltage at the plug which connects to the fan motor (with the temp sensor grounded). I can only conclude that the fan motor is dead. I located a new aftermarket fan motor that is compatible at a fraction of the OEM price. Anything I might be missing here? Share this post Link to post Share on other sites
jeepwm69 7,751 Posted July 21, 2022 29 minutes ago, Belizeted said: Well, I managed to service the coil and plug wire, but when I test started the machine the fan did not come on. I had the temp sensor lead grounded. It ran earlier in the week but today - nothing. I tried connecting 12V to the fan motor plug directly and still nothing. Then I checked continuity across the two fan plug connection and it seems the fan is shorted. I checked the fuse for the fan motor and it is fine. I also confirmed that I was getting voltage at the plug which connects to the fan motor (with the temp sensor grounded). I can only conclude that the fan motor is dead. I located a new aftermarket fan motor that is compatible at a fraction of the OEM price. Anything I might be missing here? If you're putting 12V directly to the fan motor and it's not spinning, motor is dead. Green is ground, not sure what color the hot is on the fan, but jumper wires will tell you if the fan motor is bad. I'd normally buy used OEM from ebay or powersportsnation, Share this post Link to post Share on other sites
Fishfiles 20,147 Posted July 21, 2022 It took a little extra work to make brackets , I replaced the OEM style fan with an automotive fan , I'd say it draws a lot less amps , blows harder and cost less Share this post Link to post Share on other sites
Belizeted 17 Posted July 21, 2022 Thanks for all of your helpful advice. I have pulled the fan assembly and motor out and wanted to do a final check on just the motor. I hooked up to 12V and it sputtered and quit. I realized that if I give a gentle spin with the power on, it starts up. I sprayed WD 40 on the motor shaft and bear and it seems to loosen it up a little. I will let it soak to see if it will consistenly start on its own. Regardless, I am going to need another fan motor. I would be interested in what auto fan you adapted to your machine. Down in my neck of the woods, we are always adapting things because parts are not always available or prohibitively expensive. On top of the expense of OEM parts, we have to add international shipping, plus punitive customs duty. 1 Share this post Link to post Share on other sites
Fishfiles 20,147 Posted July 21, 2022 Here is a pic of my 300 , added the cooler and fan to it as it never came with one , have also done my 450 ---- you can buy those fans from a automotive store like O'Reilly or NAPA , also on E-Bay , think it right under $50 , $40 something Share this post Link to post Share on other sites
Belizeted 17 Posted July 21, 2022 Thanks so much. Looks good. I'll keep it in mind. Leaving my fan motor to soak with WD 40, it is really loosening up and turns on right away now. I think it got corroded and that may be the whole problem. I have to re-assemble everything and take a test drive next week! Appreciate the advice. Question - as you are in a hot and humid climate (like mine) - do you run your cooler fan continuously or is it hooked up to a thermostat? Share this post Link to post Share on other sites
Fishfiles 20,147 Posted July 21, 2022 7 minutes ago, Belizeted said: . Question - as you are in a hot and humid climate (like mine) - do you run your cooler fan continuously or is it hooked up to a thermostat? Well that is a long answer , right now I am down to 7 ATVs , 4 have at least one fan with a cooler , 2 have two fans , that have one on the engine with no cooler and another on a relocated cooler , two atvs with dual fans are controlled with a controller that controls each fan separately , Retro built one of those controllers , the other is from Summit racing by David White ----- I have toggle switches installed so the fans can be overridden and turned on and off at any time , I try and turn the fan that is on the engine off , when it goes under water , e but I am not going to lie , I forget sometimes and with the sound system on , you can't hear the fan running ---when the fan is under water , you can hear it is laboring , can't be good for it , I have had OEM fans go out , but never had one of the automotive fans go out yet Share this post Link to post Share on other sites
Belizeted 17 Posted July 22, 2022 Thanks for the long answer! After a good soaking, my fan motor seems to start on command, so I am going to reassemble everything and give it a ride in the bush. Will let you know if I am successful. Share this post Link to post Share on other sites
Fishfiles 20,147 Posted July 22, 2022 I have a pedestal fan on the patio, it started getting noisy , hot to the touch and slowing down , figured out it was the front bearing , sprayed it with lubricant using a straw on a aerosol can and it got better , then I used something called Garage Door Lube which they sell at Home Depot , it is a aerosol that come out as a liquid and turns to grease , shot that thru a straw into the bearing several times , it has been 6 months or so and it is still running quiet and cool Share this post Link to post Share on other sites