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Discussion Starter · #1 ·
My old Comet 2550 will run just fine for about an hour then it will not run with the blade engaged. It will be running fine then simply stop. The engine will drive the mower fine but will not run the deck. What is going on?
 

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Possibly a heat issue with the carb & the E-gas lower vapor pressure. Do you have any smoke , smell, or other symptoms? Have you greased the blade spindle recently? How about the left axle bushing? Are the boots in good health & are the gearboxes filled with '00' grease? The latter points aren't making the blade power loss, but will hamper the mower's performance. You might want to pull the tin off the motor & thoroughly clean the cooling fins. Sharpening the blade(s) & removing the clotted cuttings from the deck will help too. That oughta be enough of a shotgun blast to get ya started!
 

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Discussion Starter · #3 ·
I thought it may be a heat issue as the fuel line runs between the carb and block. It will idle fine and drive the mower but if I engage the deck it sputters and dies. if it was vapor locking it wouldnt matter what the load is would it?
 

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It must be a fuel volume problem, so a vapor lock type issue would fit with it idling, but not sustaining power/rpm under load. Restricted filter or screens (in tank & sometimes in carb inlet fitting) is another possibility; runs until debris blocks filter or screen, but fall away after sitting a while. Reckon the vent on the gas cap is restricted/blocked? I never liked that school of fuel line routing either.
 

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Discussion Starter · #5 ·
I will clean and lube the deck and check the fuel line and tank today. It just confuses me because I was mowing tall wet grass pretty easily yesterday then suddenly it just quit.
 

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Good point H-D: Ethanol boils at 173 degrees F,(any moonshiner will tell you that)and the average small engine runs i00 degrees more than that,probably makes enough vapor to block fuel flow, Another problem that happens with heat is that sometimes coils will go bad when hot,check spark when it first quits.
 

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Discussion Starter · #7 ·
Dc it is not a spark problem as it will fire right back up after it quits. It just wont run with the deck on. Like I said it will pull the mower ok. Does the deck take more power to run than driving the mower? It is an old 5HP. Tecumseh with pull start only.
 

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I guess I'm too sentimental, but I'd give the Tecumseh a "Well done, good & faithful servant." & pull & store it for restoration. I'd hunt a bigger newer engine (cheaper in the off-season). There have been a few pictures of 'see-through' Tecumsehs posted on here lately. The wet cuttings are tougher going (more heat) & cling to the under-deck tighter (more drag & heat). It amazes me; the tenacity of the early units!
 

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I know it's only a 25 in. deck,but lots of push mowers have more power,and 5 HP was when new. It's amazing that they pull the mower and rider as well as the blade. The engine could be down on power due to mechanical problems,if the valve lifters or cam wear,the valve clearance closes up, until when hot the exhaust valve( rarely the intake) hangs open,and low compression.It's always hard to troubleshoot from a distance.It certainly takes more power to drive the deck and the mower,could it be a governor problem? the governor should add more throttle under heavier load,or maybe there's no more power to add.
 

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Discussion Starter · #10 ·
The engine has been well maintained but I do think it is down on power. This was my Grandfathers mower and I got it after he died. He had it serviced every year and stored it indoors so it is in better shape than most. It has a crankcase vent tube that is not connected to anything and it just puffs smoke out of that tube. It burns oil. A motor change may be my best bet.
 

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Discussion Starter · #11 ·
Ok I think it is dying. I cleaned the deck and lubed the spindle then tried to fire it up. It ran good but as soon as I engaged the blade it died. I started it again and noticed immediately that it was not running smoothly. It ran for just a minute then died. No amount of carb adjusting will keep it running. It will run at WOT for just a minute then it starts popping and cutting out. I have a Poulan with a 14.5 HP Briggs IC engine on it. I have posted before about pulling this engine and mounting it on my Comet. I just haven't had the guts to do it before but now seems to be the time. I have a few questions though. Will the old engine come out drive disk and all or do I have to remove the disk from the bottom and then the engine? Secondly the Poulan has a lot of safety features on it a seat switch and and a switch that wont allow it to start with the blade engaged. Can I just wire up a basic ignition system with a switch, battery, and solenoid on the Comet and get it to work?
 

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I'm not really very familiar with the Comet except through Snappers manuals etc.I would certainly try to pull it with the disc on,I know the later models will come off with the disc on. The safety systems usually work with the Mag ground,I can look it up but ,I would plan on using just what ever safety devices the Snapper has on it.
 

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If I can get it to work I found a 3005 schematic.It shows 3 switches and an interlock.It's an electric start,drawing so if yours is recoil start you can ignore the batt and wires,different switch etc.The kill wire from the engine connects to the switch at the same post as the red wire to the interlock,just take the kill wire and hook it to the post with the red wire and it should work like it always does.The photo didn't work,I'll try again ,later
 

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I've never done it,but I recall that the early RER's have "flared fenders"and the larger Briggs have added a crank case bolt on the riders left,the boss for the bolt interferes with the "fender". Some say just trim the fender till it clears some say use a later fender,without the flare. Unless you are going to pull the hub anyway,(boot change) and if you have the tools or help,trimming sounds much easier.If your 5 HP has a 1 in. dia. crankshaft you could use your drive disc,if it's still good,if it has a 7/8 in. a later one might be needed. I assume your later engine is electric start, a new switch might be needed,and some wiring(Battery cables,starter activation wire Charge wire from the rectifier,etc.)If your present one is manual start.
 

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Discussion Starter · #17 ·
Today while running my U.P.S. rout I happened upon a Craftsman push mower with a 6.5HP Briggs Intek on it. It was for sale so I asked how much it was and the guy said he would let me have it for $40.00. I thought maybe I could take the engine off it and put it on the Comet. What do y'all think? Is there any difference in a push mower engine and a riding mower engine? If the shaft is the same and the bolt pattern will line up it might work. I know 6.5 HP doesn't sound like much but it is 1.5 HP more than I have now and there will be no wiring issues. I could also keep the Poulan which I use like a small tractor more than a mower. I remember one of my Grandfathers having a Snapper 30 in. mower with a 7 HP motor on it and it worked fine. What do y'all think?
 

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It probably comes down to the crankshaft.I could be wrong,but I've never heard of a 7/8 bore drive disc,all seem to be 1in with a3&5/32 long protrusion..if the 6 1/2 has a 7/8 dia. x3&5/32 crank there is a keyed bushing that might work,to adapt it to a RER drive disc,you probably need to do some measuring.
 

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Discussion Starter · #19 · (Edited)
Ok. I have done a little searching in the past few days and I found a man with 2 used engines he will sell me. Since I don't have a lot to spend right now this is the route I want to go. One is a $50.00 Brigs 8HP. Powerbuilt. It is mounted on an old mower that they are going to scrap. The advantage to this engine is that I can hear it run. I will have to get a muffler for it though. The other is a $40.00 Brigs 11HP. I/C. The engine is complete with muffler and everything. Two weeks ago he took it off a Snapper that he had. I can't hear it run though as it is just sitting on a shelf. He says it runs good he just removed it to sell the frame to a guy whose grandson ran his square tube Snapper in to a tree and broke the front end. Are their any advantages to either of these engines? Which do you guys think is the better buy?
 

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Discussion Starter · #20 ·
I bought the 8HP. engine and got it installed this weekend. I couldn't get it to crank though so I did some searching and found that somehow the choke linkage came loose and the choke isn't closing. I didn't have time to fool with it so I will have to try again this weekend. The engine that I bought had a drive disk on it but the pulley on it was much smaller than the one on the old 5HP. engine that I took off. I decided to swap them out because I didn't want to slow the blade down any. Now I'm gonna get a new plug, muffler and air filter and get it running.
 
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