racerjohnbf 130 #1 Posted March 14, 2021 So I finally got started on my new to me 314-8. I got it running pretty easily with basically a good fuel tank flush, new fuel line with inline filter, and an in place carb cleaning. Next will be a full baseline service and I will outline that tomorrow as I saved my list on my work cpu. It runs good other than a loud backfire if you throttle down too fast. Seems like it's getting a little too much fuel because it will also give a puff of black smoke on quick acceleration. It a Walbro fixed main jet carb..... Thinking maybe a leaky inlet needle? Also I noticed a fairly deep groove in the front axle that appears to have come from the mule drive pulley. Should I be concerned about this weakening the axle? Its probably a good 1/4 inch deep. Share this post Link to post Share on other sites
roadapples 6,983 #2 Posted March 14, 2021 Can't imagine using it hard enough for that groove to hurt anything... 1 1 Share this post Link to post Share on other sites
CCW 1,300 #3 Posted March 14, 2021 If it works as well as my 312-8 you have a great machine. 2 1 Share this post Link to post Share on other sites
racerjohnbf 130 #4 Posted March 14, 2021 (edited) 48 minutes ago, roadapples said: Can't imagine using it hard enough for that groove to hurt anything... That's what I was hoping to hear. I was figuring to just fill it with JB weld and put some touch up paint over it. Just didn't know if it being a groove would make for weak spot for the cast iron to crack. 36 minutes ago, CCW said: If it works as well as my 312-8 you have a great machine. Thanks! I can't wait to put it to work. Edited March 14, 2021 by racerjohnbf 1 Share this post Link to post Share on other sites
racerjohnbf 130 #5 Posted March 14, 2021 A couple more pics of the groove.... Share this post Link to post Share on other sites
CCW 1,300 #6 Posted March 14, 2021 (edited) I would not worry about that groove at all. Edited March 14, 2021 by CCW 2 Share this post Link to post Share on other sites
Ed Kennell 38,249 #7 Posted March 14, 2021 Just a minor battle scar. Probably made it a tougher machine. 4 Share this post Link to post Share on other sites
elcamino/wheelhorse 9,326 #8 Posted March 14, 2021 I would not worry about that little scar. Glad to heard you got it running . I save old tractors , sells a great replacement carb. 1 Share this post Link to post Share on other sites
Jeff-C175 7,202 #9 Posted March 14, 2021 I'm curious as to how the mule drive pulley could have dug into the axle like that? Was something installed wrongly? I'd be more concerned about the condition of the pulley myself. 3 Share this post Link to post Share on other sites
racerjohnbf 130 #10 Posted March 14, 2021 @CCW @Ed Kennell @elcamino/wheelhorse Thanks! I don't have a problem with a few battle scars. I'm sure she'll get a few more. I'll probably rebuild the original carb correctly at some point, injustice couldn't wait to hear her run. Any ideas on the backfire? Share this post Link to post Share on other sites
racerjohnbf 130 #11 Posted March 14, 2021 1 minute ago, Jeff-C175 said: I'm curious as to how the mule drive pulley could have dug into the axle like that? Was something installed wrongly? I'd be more concerned about the condition of the pulley myself. That's a good question. I'll certainly investigate further before I hook up the mule drive and deck again. 1 Share this post Link to post Share on other sites
Jeff-C175 7,202 #12 Posted March 14, 2021 (edited) 10 minutes ago, racerjohnbf said: Any ideas on the backfire? SOMEtimes... and I'm hesitant to say this... backfire can be caused by leaky exhaust valve. Can you do a cylinder 'leak down test'? You might also consider pulling the head and decarbonizing everything. Sometimes the carbon buildup gets red hot and can ignite the mixture when it shouldn't be ignited. My neighbors brand new green tractor backfires every time he shuts it off. There's some sorta electric gadget on the carb that is supposed to stop if from doing this but I don't know what that gadget does. Some sorta fuel cut off solenoid? Edited March 14, 2021 by Jeff-C175 3 Share this post Link to post Share on other sites
racerjohnbf 130 #13 Posted March 14, 2021 @Jeff-C175 Yes I hadn't thought about a leak down test, but I'll try that. Appears to be excess fuel on acceleration and deceleration. If I raise the throttle from idle to full too quickly I get a puff of black smoke. And if I reduce throttle from full to idle too quickly I get a loud backfire. If I make throttle adjustments slower everything seems normal. It does this even if the engine has only run a few mins to warm up first. And no backfire at shutdown. 1 Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,055 #14 Posted March 14, 2021 I would run some Marvel Mystery oil in the fuel and see what happens. Garry 3 Share this post Link to post Share on other sites
racerjohnbf 130 #15 Posted March 15, 2021 11 minutes ago, gwest_ca said: I would run some Marvel Mystery oil in the fuel and see what happens. Garry Thanks for the tip I'll try that. Seafoam is usually my additive of choice. Would that do the same thing? Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,055 #16 Posted March 15, 2021 I find the MM oil does a better job of lubricating the valve stems. There is something in it that does not burn. A spark plug always looks wet. Garry 1 Share this post Link to post Share on other sites
racerjohnbf 130 #17 Posted March 15, 2021 17 minutes ago, gwest_ca said: I find the MM oil does a better job of lubricating the valve stems. There is something in it that does not burn. A spark plug always looks wet. Garry Ok. I will try the MM oil, in this case the lubrication is probably needed. Will the MM oil also help clean up the carb like Seafoam? Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,055 #18 Posted March 15, 2021 They claim it does but have never compared the results. I think Seafoam works faster as a cleaner in the carb. Garry 1 Share this post Link to post Share on other sites
racerjohnbf 130 #19 Posted March 15, 2021 6 hours ago, gwest_ca said: They claim it does but have never compared the results. I think Seafoam works faster as a cleaner in the carb. Garry Thanks. I picked up a bottle of MMO today! Share this post Link to post Share on other sites
haydendavid380 759 #20 Posted March 15, 2021 (edited) IMO none of the miracle cleaners do anything compared to just dropping the bowl and wiping it out then blowing some air through the ports. These carbs are easy to get on and off and work on. If try giving it a good cleaning and try to get the carbon off the valves. Someone smarter than me can chime in here, but what about a timing issue? Edited March 15, 2021 by haydendavid380 1 Share this post Link to post Share on other sites
WVHillbilly520H 10,373 #21 Posted March 15, 2021 9 hours ago, gwest_ca said: They claim it does but have never compared the results. I think Seafoam works faster as a cleaner in the carb. Garry From my experiences Berryman's B-12 is a better carb/fuel system cleaner than Seafoam, plus its cheaper per can, you can't add it to the crankcase oil, and if you pour it into a Styrofoam cup it will melt it Seafoam doesn't, plus their 1 gallon Chem-dip carb soaking buckets, MMO has transmission fluid in it for the lubrication. JMO, experiences. 2 Share this post Link to post Share on other sites
Jeff-C175 7,202 #22 Posted March 15, 2021 23 hours ago, racerjohnbf said: I hadn't thought about a leak down test If you do perform the leak down, put your ear to the tailpipe and the carburetor to see if you can hear the hisssssssssssssssss... 2 Share this post Link to post Share on other sites
lynnmor 7,315 #23 Posted March 15, 2021 3 hours ago, haydendavid380 said: IMO none of the miracle cleaners do anything compared to just dropping the bowl and wiping it out then blowing some air through the ports. These carbs are easy to get on and off and work on. Other than gasoline, the only product I use is carburetor cleaner in a spray can to blast thru the tiny holes of a disassembled carburetor. 1 Share this post Link to post Share on other sites
WVHillbilly520H 10,373 #24 Posted March 16, 2021 18 minutes ago, lynnmor said: Other than gasoline, the only product I use is carburetor cleaner in a spray can to blast thru the tiny holes of a disassembled carburetor. If you pull and have "soak" it which brand so you use? Share this post Link to post Share on other sites
racerjohnbf 130 #25 Posted March 16, 2021 4 hours ago, haydendavid380 said: IMO none of the miracle cleaners do anythin... ....but what about a timing issue? Good points. Is the timing adjustable on on the magnum 14? 2 hours ago, WVHillbilly520H said: if you pour it into a Styrofoam cup it will melt it Seafoam doesn't, plus their 1 gallon Chem-dip carb soaking buckets, That Chem-dip is strong stuff. It cleans very well but I'm always a little worried about it eating any plastics parts if a carb is not completely disassembled. These days I like to use an ultrasonic instead. The ultrasonic works good but sometimes it won't touch stuff the the Chem-dip would. 52 minutes ago, Jeff-C175 said: If you do perform the leak down, put your ear to the tailpipe and the carburetor to see if you can hear the hisssssssssssssssss... Yes sir, will do. 19 minutes ago, lynnmor said: Other than gasoline, the only product I use is carburetor cleaner in a spray can to blast thru the tiny holes of a disassembled carburetor. Yep the carb is due to for a proper cleaning. I just pulled the bowl nut to get some brake cleaner through the main jet and shot some through the other passages I could get to without disassembling since I didn't have new gaskets. I really just wanted to see if it would start. Share this post Link to post Share on other sites