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greene1564

Big Ten with no power under a load

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greene1564
I have a 65 Big Ten the motor has been replaced with a briggs 302431 0155-01 750821 I was told that it was an 18 hp but I am not sure of this. The problem I am having is that the tractor starts perfect an idles flawlessly and can even be brought up to full throttle until it is put under any load even engaging the blades makes it bog down and act like it is choking out back fire through the exhaust and die I can put it back to an idle hit the button and it fires right back up with no problems, It has the automotive style coil, new points all the wiring is new and even the plug and wire is new. the starter button and the ignition switch is new and the carb has had a rebuild kit and a new bottom assembly because the other was cracked. the points was set to .020 with some minor adjusting after it was running. The plug is gapped at .030 and the carb has been adjusted to death with out any results any help would be appreciated. Thanks, Sam

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BLT
Your engine is rated @ 11-13 HP dependng on what MFG was selling it. It also sounds that the governor is a little slow to react and needs to be readjusted. Here is an excerpt from another thread. "Posted in an earlier post by AL: Hi, The way they teach it at the Briggs school, Forget about clockwise or counter clockwise. [Assuming the correct carb] Just take the governor arm and move it in the direction that opens the carb wide open. Holding the arm so the carb is wide open, loosen the bolt on the arm and turn the governor shaft in the same direction the arm rotated when opening the carb. When the shaft hits the stop, tighten the bolt while the carb is wide open. Same with Kohler. Much simpler than trying to remember cw or ccw. Remember the governor weights must be held in when the carb is wide open and then they work against the spring to control the speed. Also if the engine is hunting, to determine if it is the carb or the governor, turn in the idle stop screw and hold the carb shaft against the idle stop. If the engine idles OK, then run the stop screw in more and hold it against the stop. If it runs good at mid speed with the throttle shaft fixed it is a governor problem. If the engine is erratic with the throttle shaft fixed, it is a carb problem. Personally I just hold the shaft by hand, but in school they teach using the screw for a stop. Good luck, Al Eden"

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greene1564
Thank you BLT for the quick reply I adjusted the governor as stated and it was adjusted with no extra movement movement in the shaft after loosing the bolt. I am goin to try the set screw procedure and see what this turns up. I tried the set screw procedure as stated and it seems to do fine at 1/2 throttle but it still seems fine just using the regular throttle linkage until I put it under a load. I can fix and work on any car but when it comes to these small 1 cylinders they keep me stumped

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greene1564
Well I have spent a few hours adjusting tweaking and tuning, trying different combinations of adjustments with the points and the carb but have not made any progress, it just seems to be getting worse. I guess I am going to have to break down and take it to a shop.

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Tarheel
Sounds to me like you have valve trouble such as overly tight or sticky valve guides or a broken or weak exhaust spring. In any of the above the exhaust valve moves fast enough to run low speed but the faster you go, the more the valve lags. This means that the "bang" from the fuel/air is mostly going out the exhaust. If you remove the spring and work the valve in the guide. If you feel a little drag ( and it don't take much ) Cleaning the valves and polishing the stems with jewelers rouge is a good starting point. Try spray carb cleaner in the guides and see if you can cut the varnish out with it but a guide reamer would be best.

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greene1564
I did tinker with it some more decided not to go to a shop, cause I am determined to to do it, I guess man pride at work RayS, here is a pic of the gov [IMG]http://i1254.photobucket.com/albums/hh619/samdgreene/0317121240.jpg[/IMG] and here is the carb [IMG]http://i1254.photobucket.com/albums/hh619/samdgreene/0316121424a.jpg[/IMG] Tarheel I have also thought about the valves, but that is not my expertise..lol here is video of the engine running http://s1254.photobucket.com/albums/hh619/samdgreene/?action=view¤t=0317121150.mp4 Thanks for the help

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Talntedmrgreen
Hmmm...Governor springs should look like this, and your intake manifold looks like it's off a 30+CID engine. [img]http://i1239.photobucket.com/albums/ff512/talntedmrgreen/IMAG0076.jpg[/img]
[img]http://i1239.photobucket.com/albums/ff512/talntedmrgreen/IMAG0709.jpg[/img]

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RayS
The manifold is ok. They went to the longer manifold when they came out with the paper element. The paper elements are longer than the foam element. I have a new 10hp with the same manifold. If he changed the manifold to long and didn`t change the governor linkage to the governor arm there would be a problem. The shorter manifold has a longer governor linkage.

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greene1564
well I went out and messed with the springs on the governor and the one that went to the peg close to the end broke off at the peg. do I need to order another spring or can I make one with small carb springs off of a car? and another question, when you guys set your points do you set them at .020 and leave them or do you have to adjust to get the engine running smooth through the full throttle range. I set mine at .020 and when I started messing with it I could only get about 1/2 throttle until I started to close the gap slowly while working the throttle up until I had full throttle that was smooth. Now when I checked the gap it is like .011 would this be normal or is something else messed up. it does have the external kohler coil on it and I did not know if this was a correct for that mod.

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greene1564
BLT thanks again, that is what I thinking but was not sure. Willy, I have tried it with the filter off with the same results, I am goint to get a factory style filter for it when I can I just put that one on there to keep debri from going into the carb, had some junk fly into a new rochester carb on a car once and had to do a rebuild to get it back to normal, so I dont like to run anything without some sort of air filter anymore.

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briggs9498
I don't know if it would matter or not but that fuel filter is wrong too. That's the type for an engine with a fuel pump I believe. I would think it would limit the fuel flow but I'm not positive.

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1Litre
The air filter looks very dirty. It is a crankcase breather filter from K&N and it is a little small for the engine. Is the condenser a Kohler condenser with a black wire about 3" long? If it is the one with the short wire or just a tab for a screw it is the wrong condenser. Is your charging system in proper order so you have a minimum of 12V ? The battery ignition looses power as the input voltage decreases. When you remove the fuel line do you get a full stream of fuel threw the hose ? I have found dead bugs stuck in nipples ,elbows thet restrict flow. If the float height is set wrong it can starve for fuel .

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greene1564
briggs9498, I picked the fuel filter up at oreilly's auto parts in the small engine section it said that it was for engines without a fuel pump and the clear one said it was for engines with a fuel pump. I just went by the package cause I didnt know what the difference was until I read the packaging. 1litre, The air filter was an old breather off of my yamaha 750 (K&N knock off) and yea it is dirty, I did clean it but after they get some age some stuff just dont come out. I will look into getting a different one in the next couple of days. The condenser was ordered with the coil, points and plug wire from jacks and it does have the big mounting bracket and 3" wire here are the part numbers 298185 BREAKER IGNITION, 455147 CONDENSER, 460048 IGNITION COIL, 135178 COIL WIRE. The charging system is working, the old gen is putting out a little over 12V to 13.5V depending on speed and battery usage. I will be going through another Gen I have lying around cause the bearing in the one on the tractor is starting to make some noise. The fuel is flowing with a large stream when I remove the line at the carb. The float is new the other one had a pin hole in it and was taking on fuel causing flooding, that is was got the carb redone. The float was set so when I turned the top section of the carb over and laid it on a flat surface that it measured even all the way around it from the mounting surface of the top, without the gasket and then rechecked it with the gasket, which I read that on the net some where that is why I did it that way. These carbs are a very simple design and that is why I keep thinking in the back of my mind I screwed something up on it cause it went together so well..lol

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Ronald Hribar
You said when you put it under load that bogged down. Does it bog down when you drive around the yard? Or just when you engage mower.? It maybe that the deck has problems

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RayS
I have been using those red round filters for over 10 years on my Briggs. They have a 150 micron rating and are for engines without a fuel pump. It should be the correct filter Briggs number 298090S

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briggs9498
I must have been thinking about the white/clear ones in that style sorry about that. I personally use the big clear ones because I like to see the gas that is flowing throw it to make sure the filter's not dirty. I just watched the video of it running and noticed quite a bit of smoke on throttle up. Almost looks blue to me but can't tell with the video. How is oil consumption? Rings might be worn out and that would cause it to lose power under load. As far as the intake manifold goes I believe that is correct for the engine as I looked at your pictures on photobucket. The engine appears to be from a rbt because it has a dipstick and they would all have that manifold. My 10,15, and 16s have it. My 12hp in my fdt has the shorter old style manifold.

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greene1564
Ronald Hribar, I can drive i around the yard in first gear but it is slugish it is mainly when I go to second or try tp pull up a grade in first when it boggs down and then dies out. briggs9498, it really does not use any oil and the smoke is white that is comming out it might be slight gray but mostly white. I dont want to sound ignorant but what is an rbt, this has me puzzled. I was told the engine came off a small roller for asphault but I was also told it was an 18hp so who knows, but I didnt think I did bad for $100 that was complete with gen and carb and around here in east TN it is hard to find ay type of engine for under $150 or $200 that I have seen. I removed the cylinder head to clean and check for carbon build up it had some, got it all cleaned up and noticed that the intake valve when it is completely closed it can still be turned by hand, I was wondering if this is normal on these smaller engines cause I know valves in the head of a car are tight and will not move by hand. I was thinking this would be the same with all valves but wanted to get some input

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BLT
Turning any valve when they are both closed indicates that they are resting on the tappets and that will cause a loss of power. Refacing the valves and lapping them in might cure your problem. White exhaust is an indication of unburned lube oil. RBT = Running Board Tractors and FDT = Foot Dragging Tractors.

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