shawn76 0 Posted February 28, 2023 (edited) anybody have any idea why this machine floods it self out when cold out if it 35 degrees plus it starts below it will flood itself out need to pull plug then blow fuel out of cylinder then starts if in a warm garage seems like its getting to much fuel thanks in advance Edited February 28, 2023 by shawn76 miss spelled word Share this post Link to post Share on other sites
shadetree 5,880 Posted February 28, 2023 1 hour ago, shawn76 said: anybody have any idea why this machine floods it self out when cold out if it 35 degrees plus it starts below it will flood itself out need to pull plug then blow fuel out of cylinder then starts if in a warm garage seems like its getting to much fuel thanks in advance weather temp has no bearing on why it will or won't start , unless its like 50 below ?..lol. the 420's are fuel injected, they have a fuel pump, which is very common to go out, last but not least, they have a fuel injector at the throttle body. could be a dirty fuel injector ?, maybe need a new spark plug ?, there are different spark plugs for different heat ranges, although..heat ranges and temperatures has nothing to do with it not starting. put some fuel injector cleaning stuff in the tank, run it a bit if you can get it to start ?, this may help the fuel injector. also try a new spark plug. worse case ?, the fuel pump is getting to weak to allow fuel pressure to the fuel injector. Share this post Link to post Share on other sites
shawn76 0 Posted February 28, 2023 20 minutes ago, shadetree said: weather temp has no bearing on why it will or won't start , unless its like 50 below ?..lol. the 420's are fuel injected, they have a fuel pump, which is very common to go out, last but not least, they have a fuel injector at the throttle body. could be a dirty fuel injector ?, maybe need a new spark plug ?, there are different spark plugs for different heat ranges, although..heat ranges and temperatures has nothing to do with it not starting. put some fuel injector cleaning stuff in the tank, run it a bit if you can get it to start ?, this may help the fuel injector. also try a new spark plug. worse case ?, the fuel pump is getting to weak to allow fuel pressure to the fuel injector. i know its fuel injected have tried fuel injector cleaner and new oem plug it floods itself out so its getting fuel and there is spark and only happens when below 30degrees out and running 87 octane fuel its spraying to much fuel Share this post Link to post Share on other sites
shadetree 5,880 Posted February 28, 2023 27 minutes ago, shawn76 said: i know its fuel injected have tried fuel injector cleaner and new oem plug it floods itself out so its getting fuel and there is spark and only happens when below 30degrees out and running 87 octane fuel its spraying to much fuel if it's flooding the spark plug ?, then odd's are, the spark is weak ?, or the timing is off a tad ?. have you checked the compression ?. have you checked the timing ?. Share this post Link to post Share on other sites
shawn76 0 Posted February 28, 2023 i have not check timing it has good compression i will see how to check timing and the spark its just weird how it starts fine in warm weather only does it in the cold Share this post Link to post Share on other sites
shadetree 5,880 Posted February 28, 2023 1 hour ago, shawn76 said: i have not check timing it has good compression i will see how to check timing and the spark its just weird how it starts fine in warm weather only does it in the cold cold temps effect the battery, maybe the battery is too weak to operate the fuel pump ?. Share this post Link to post Share on other sites
Snow Camo 242 Posted March 1, 2023 Engine Coolant Temp (ECT) Sensor (37870-HN8-A61) - Intake Air Temperature (IAT) Sensor (37880-MCA-003) I bet just like any other engine one of these is you issue. Likely the IAT (intake air temp) sensor. Idk but these are in the loop that control fuel. 1 Share this post Link to post Share on other sites
toodeep 1,758 Posted March 2, 2023 I would start with a new iridium spark plug (they do make a difference in the cold weather) and make sure the battery is 100%. Are you waiting for everything to cycle before trying to start it? Another thing I have ran into is fuel. Against everything everyone will tell you, I have had the best results with the 10% ethanol in the cold weather. Straight unleaded would lead to long starts or the flooding problem your having. I have 3 420s and a MUV700 BigRed. They all start a little different in the cold weather but they never fail to start. I have one customer that has to get fuel from a different supplier and the 10% in the winter months or his machine refuses to start unless it's warm (his farm tank gets filled with unleaded). For the really cold starts (temps in the negatives) there is a procedure to help them that works great but lets start with the basics for these warmer cold starts. 2 Share this post Link to post Share on other sites
shawn76 0 Posted March 2, 2023 we do wait to let fuel pump and everything get ready getting new plug and just ordered a new coil pack the spark looked a little week and inconsistent also pulled injector and checked spray pattern it is good and compression is good and battery is 100% we will see when coil comes in since dealer says they do go week Share this post Link to post Share on other sites
shawn76 0 Posted March 2, 2023 (edited) 16 hours ago, toodeep said: Edited March 2, 2023 by shawn76 Share this post Link to post Share on other sites
toodeep 1,758 Posted March 2, 2023 @shawn76 I'll post it here in public for everyone to see. 2 Share this post Link to post Share on other sites
toodeep 1,758 Posted March 2, 2023 If your getting a new sparkplug get a IFR5L-11 and not the BKR5E-11. The iridium plug costs more but it is worth it. Share this post Link to post Share on other sites
