bowtieboy77
Member
My fathers 1978 mf 135 perkins gas with zenith carb ran great all summer. In the fall it would not start I diagnosed it to be points that welded togeather. I am a truck and coach tech but am always learning and small gas engines is not my strong suit. I replaced plugs, points and condenser and set gap to spec. When it started it was running very rough, back fired, and huffing black smoke. I tried setting timing by ear to get engine to smooth out and stop smoking but was unable to get it better. I used it a little around the yard and it got to the point were it would stall and be very hard to start and would only run by manipulating the choke on and off.
I had the massey dealer pick it up and they had it for 1.5 months and the bill was $800 parts and labour. The points and condenser was replaced, coil, plugs, carb (disassembled and reassembled) set timing, and a ballist resistor to coil. Service manager stated they were suspicious the tractor was a 12v conversion which is the reason for the ballast resistor. The tractor is a original 12v and never had a ballist resistor previous. I also have lost trust in the dealer as I thought they would diagnose better but it seems they just loaded the parts cannon and fired. That was why I stopped figured dealer would have more experience.
The Tractor ran better when delivered but when driving around yard the rpm s dropped and backfired then rpms picked up again. Talked to dealer they said a spec of dirt could have got in carb. Started in on Saturday and it backfired while running. I shut it off and went to start it later it was very hard to start and as ealier would only stay running by moving choke to on then when it would start to stall taking choke off then it would start to stall and move choke on etc.
I am suspicious it is carb related due to the choke manipulation to keep it running. I am running a small (older ford pickup carb) filter threaded into the card which I know is not advised but it also ran the filter during the summer when it was running well. I am going to clean the screen at the sediment bowl and see if I have good fuel flow through the screens and filter. If that checks out my friend rebuilds marvel and zenith carbs as a hobby and is very good at them so I will see if that helps.
Any opinions or suggestions is appreciated.
I had the massey dealer pick it up and they had it for 1.5 months and the bill was $800 parts and labour. The points and condenser was replaced, coil, plugs, carb (disassembled and reassembled) set timing, and a ballist resistor to coil. Service manager stated they were suspicious the tractor was a 12v conversion which is the reason for the ballast resistor. The tractor is a original 12v and never had a ballist resistor previous. I also have lost trust in the dealer as I thought they would diagnose better but it seems they just loaded the parts cannon and fired. That was why I stopped figured dealer would have more experience.
The Tractor ran better when delivered but when driving around yard the rpm s dropped and backfired then rpms picked up again. Talked to dealer they said a spec of dirt could have got in carb. Started in on Saturday and it backfired while running. I shut it off and went to start it later it was very hard to start and as ealier would only stay running by moving choke to on then when it would start to stall taking choke off then it would start to stall and move choke on etc.
I am suspicious it is carb related due to the choke manipulation to keep it running. I am running a small (older ford pickup carb) filter threaded into the card which I know is not advised but it also ran the filter during the summer when it was running well. I am going to clean the screen at the sediment bowl and see if I have good fuel flow through the screens and filter. If that checks out my friend rebuilds marvel and zenith carbs as a hobby and is very good at them so I will see if that helps.
Any opinions or suggestions is appreciated.