Jeff Yost 0 Posted October 16, 2017 Why does my fv721 fox overheat at about ten miles? Share this post Link to post Share on other sites
1 Diana and Jackie 10 Posted October 17, 2017 Why don't you have the service manual? It's the first thing anyone buying a MV should get after buying the vehicle. If you don't have the manual (provided you can get one), and there are plenty available for the Fox, then you will have a problem looking after it and resolving problems. 1 Share this post Link to post Share on other sites
0 sirhc 21 Posted October 16, 2017 You’re not giving us much to help us help you out! Share this post Link to post Share on other sites
0 robin craig 11 Posted October 16, 2017 Jeff, I am going to ask all the stupid questions to you so we can eliminate some causes. Have you first paraded your vehicle? Was the coolant level up? Was the Oil level up? Was the fan belt to the blower volute bevel box in place? Do you have a manual Where in the world are you located? What is your ambient air temperature? What altitude are you operating at? What mix of coolant to water are you using? What gear are you driving in at what speed? How long have you owned the vehicle? Has it ever run at the normal operating temperature, ever? Share this post Link to post Share on other sites
0 Jeff Yost 0 Posted October 17, 2017 Located in Michigan, US. Takes about 10 miles of 50 mph and it over heats. as it did for previous owner. Had a mechanic drill a little hole in the thermostat like the original but didn't fix it. Lots of anti freeze. Share this post Link to post Share on other sites
0 sirhc 21 Posted October 17, 2017 Have you bled the air out of the cooling system? Share this post Link to post Share on other sites
0 Diana and Jackie 10 Posted October 17, 2017 Lots of antifreeze? how much is lots ? is it 50/50 ? because if its more than 50/50 that maybe the cause. Get a device for measuring the ratio and do a proper check. Diana Share this post Link to post Share on other sites
0 Jeff Yost 0 Posted October 17, 2017 I will check anti freeze ratio. How do I bleed air? Share this post Link to post Share on other sites
0 andym 20 Posted October 17, 2017 http://www.greenmachinesurplus.com/cvrw-fox-125-c.asp perhaps? Andy Share this post Link to post Share on other sites
0 sirhc 21 Posted October 17, 2017 There is a bleed point on each radiator, just undo the bolt and wait until water comes out. There is also one on the water pipe which goes across the engine to the heat exchanger. Share this post Link to post Share on other sites
0 Jeff Yost 0 Posted October 18, 2017 Thank you all for the feed back I will try the suggestions. Share this post Link to post Share on other sites
0 Richard Farrant 22 Posted October 18, 2017 No one has mentioned the water pump drive belt yet, they were prone to failure in service. Share this post Link to post Share on other sites
0 Starfire 11 Posted December 5, 2017 Did you get it sorted? Share this post Link to post Share on other sites
0 Jeff Yost 0 Posted December 6, 2017 no. My plan is to remove the 2 radiators and send them to a shop to have them roded. Thanks Share this post Link to post Share on other sites
0 Jeff Yost 0 Posted August 6 I had radiators checked and all is good. Is it possible of a bad pressure relief valve. Share this post Link to post Share on other sites
0 Jeff Yost 0 Posted August 7 On the last test run after approximately 10 miles it reached 200 degrees and I stopped. The radiator covers were very hot. The engine covers were only warm. Share this post Link to post Share on other sites
0 terryb 11 Posted August 7 Jeff, If the rads have tested ok, then its one of 4 things; lack of coolant-fill header to brim and bleed air out with engine running at temperature. coolant flow insufficient-water pump/drive belt/coolant passage blockage Insufficient cooling air flow through rads-rads fins blocking air flow? fan moving enough air? all plates fitted ? headgasket failure- run on fast idle with header tank cap open and filled to brim-are bubbles/coolant coming out on hard acceleration? Share this post Link to post Share on other sites
0 Diana and Jackie 10 Posted August 7 And a thermostat seized closed Diana Share this post Link to post Share on other sites
0 terryb 11 Posted August 7 Just to add, I asked my colleague who drove a fox this weekend to a show, who said his gauge was showing 185-190f. Share this post Link to post Share on other sites
0 Jeff Yost 0 Posted August 11 This time I didn't stop at 205 degrees only being a couple miles from home. It rose to 220 when I stopped and was boiling when I shut it off. Then went to 250 not running. It lost only a few drops of anti freeze. Does this mean anything? Share this post Link to post Share on other sites
0 sirhc 21 Posted August 11 Jeff, Have you checked all the things previously mentioned in this thread? Can you post a photo of the rear of the vehicle? Chris Share this post Link to post Share on other sites
0 Diana and Jackie 10 Posted August 11 Remove the thermostat and I'd concur with Chris Diana Share this post Link to post Share on other sites
0 Jeff Yost 0 Posted August 12 Have not tried all suggestions. Share this post Link to post Share on other sites
0 sirhc 21 Posted August 12 You have all the right bits in place so that’s a good start. Share this post Link to post Share on other sites
0 Richard Farrant 22 Posted August 12 31 minutes ago, Jeff Yost said: Have not tried all suggestions. Jeff, just looking at the photo you posted. The silencer / muffler looks like it could be reproduced item. If it is not made correctly inside it could create back pressure and the restriction will cause overheating. Can you confirm if it is a copied part? regards, Richard Share this post Link to post Share on other sites
0 Jeff Yost 0 Posted August 13 How do I know correct/stock muffler from repro? Share this post Link to post Share on other sites
Why does my fv721 fox overheat at about ten miles?
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