Bobcat 742 Running Rough - Any Thoughts??

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VAFarmUse

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Nov 20, 2018
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I have a 742 with the Ford 1.6L 4 cyl gas engine. I have been battling an issue where sometimes I start it up and it runs great, while other times, I start it up, and I have to keep the choke on, or it will start to sputter and die. Sometimes after playing with the choke, you will hear the engine suddenly clear up, and then run great with no choke. If you are running it while it is in the "I need choke" phase, as soon as you put any strain on the hydraulics, like begin to take a scoop of dirt with the bucket, the engine will start to sputter until you stop and stay still, and then it will pick back up. Any ideas what this could be? I have the electronic fuel pump, and it seems to push fuel sufficiently, but I think that could still be the issue. I do have an in-line fuel filter between the tank and the fuel pump that I try and change fairly often, but i've never been convinced thats helped one way or the other. I feel like its probably something fairly simple, since it will sometimes "heal itself" and fun fine, but whether it then runs good for 2 weeks or 20 minutes is anybody's guess. Also, I did pull the fuel intake and look at/clean the metal screen, which looked fine to me, but I have not done anything with the gas tank itself. I have also replaced the fuel line from the tank all the way to the electronic fuel pump, but I couldnt get my hands on the portion from the fuel pump up to the carb (I didnt feel comfortable pulling it off the carb, because I wasnt sure I could get it back on, due to how tight the space was back there). I can do some simple things on the engine, but certainly no mechanic, so any feedback, thoughts, etc. would be appreciated. Many thanks.
 

Tazza

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The starting issue sort of makes me think it could be a dirty carb, the bogging down when loading the engine could also be the carb, but it could be the govenor too. The idea is, when you load the motor down, the govenor gives the carb more throttle to maintain speed. I think these govenors were external, so need to have their oil changed. Over time, they leak and can run dry and fail.
I have never worked on one, so i can't give tips on how to get the old carb off or adjust it with the govenor, hopefully another member can assist though.
 

Wayne440

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Sep 24, 2017
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Start by setting the points to .020, they are fussy on this engine.
(1) as mentioned, the points are a possible problem. (2) rubber fuel hose can disintegrate from the inside out, the more difficult to change, the more likely that the hose is bad. (3) maybe it is trying to vapor lock, the cooling system is not the best design on these. (4) to me, this is not likely to be a governor problem, but changing the oil is advisable, and do not run the belt too tight
 

craigb93

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Nov 9, 2010
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(1) as mentioned, the points are a possible problem. (2) rubber fuel hose can disintegrate from the inside out, the more difficult to change, the more likely that the hose is bad. (3) maybe it is trying to vapor lock, the cooling system is not the best design on these. (4) to me, this is not likely to be a governor problem, but changing the oil is advisable, and do not run the belt too tight
Most likely culprit is the carb. Look for old posts under my name regarding cleaning the carb emulsion tube. First though, just loosen the fuel cap and run for a while. A bad cap won't won't drain by gravity to the pump if it can create a vacuum. Also a good fuel tank cleaning is in order if you have used much ethanol containing gas. Use only ethanol free fuel. Best easy procedure for tank cleaning is pour a quart of 'Greased Lightning' and a couple of quarts of water in the empty tank after you remove it from the machine. Add a good handfull of clean sharp 3/8" gravel and shake shake shake. Rinse w/ water hose. -Dick
 
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VAFarmUse

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Nov 20, 2018
Messages
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Most likely culprit is the carb. Look for old posts under my name regarding cleaning the carb emulsion tube. First though, just loosen the fuel cap and run for a while. A bad cap won't won't drain by gravity to the pump if it can create a vacuum. Also a good fuel tank cleaning is in order if you have used much ethanol containing gas. Use only ethanol free fuel. Best easy procedure for tank cleaning is pour a quart of 'Greased Lightning' and a couple of quarts of water in the empty tank after you remove it from the machine. Add a good handfull of clean sharp 3/8" gravel and shake shake shake. Rinse w/ water hose. -Dick
Hey everyone, Thanks for the info. I took a look yesterday for a few minutes and changed out the in-line fuel filter and tested the electronic fuel pump to see if it was failing. In my opinion, it was pushing fuel pretty damn well, so I dont think thats an issue. I can do some of the things mentioned like pull/clean the tank, but some of the suggestions are getting a bit over my head in terms of my mechanical skills. I watched some videos on points, so i think I could do that, but not too comfortable with the carb or anything to do with timing, etc. I am located about 30 min from Richmond VA and 30 min from Charlottesville VA. I was wondering if anyone knew of a mechanic in the area who may be able to come take a look? I would feel more comfortable having someone with more experience take a look and maybe I can learn a bit from there. Also, if anyone reading this is nearby and wouldnt mind giving me a hand, I will be happy to pay for your help, along with some cold drinks as a thanks. Much appreciated.
 

dirtpig538

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Mar 28, 2010
Messages
93
Hey everyone, Thanks for the info. I took a look yesterday for a few minutes and changed out the in-line fuel filter and tested the electronic fuel pump to see if it was failing. In my opinion, it was pushing fuel pretty damn well, so I dont think thats an issue. I can do some of the things mentioned like pull/clean the tank, but some of the suggestions are getting a bit over my head in terms of my mechanical skills. I watched some videos on points, so i think I could do that, but not too comfortable with the carb or anything to do with timing, etc. I am located about 30 min from Richmond VA and 30 min from Charlottesville VA. I was wondering if anyone knew of a mechanic in the area who may be able to come take a look? I would feel more comfortable having someone with more experience take a look and maybe I can learn a bit from there. Also, if anyone reading this is nearby and wouldnt mind giving me a hand, I will be happy to pay for your help, along with some cold drinks as a thanks. Much appreciated.
Water in the fuel?
 
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