First off, i'm new to this forum, so I figured i'd say hello.
i've got a Honda HT3813 that i've had since new, 1990 and absolutely love it
I ran it for about 12 years before putting it in mothballs and just recently took it out and have gone thru it getting it back in shape for full time service. In fact i like it so much, i just bought a clunker off egay to have for spare parts.
just finished changing the timing belt, wasn't a big deal as i used to mechanic back in the 60s & early 70s at Datsun/Nissan & BMW dealership.
Problem that's just surfaced, i was cutting the grass (about a 2 acre yard) and toward the end it started surging kind of oddly - kind of a sudden loss of power for maybe a 1/10th of a second where rpm drop off then it quickly comes back.
I had remembered seeing a couple of postings on orphaned chat threads that i'd googled back in the spring, about thrust washer/bushing svc bulletin for the hydrostat transmission honda apparently had put out, but for some reason google isn't pulling those same threads up again.
But any assist on this is appreciated - the surging occurs whether the LT is in gear and roll, with or without blades turning, and even if sitting still on level ground. It starts to surge about 2200 rpm and becomes real pronounced around 3000 - 3400 rpm. It sure sounds/feels like fuel or electric, and i can't imagine how a bushing in the transmission could cause it when the tractor is sitting still, but that drive shaft is live or solid connection with the flywheel.
I did check the governor adjustment, per the svc manual, and it was spot on.
some history on svc performed past few months -
1) new timing belt was just installed - i was real careful lining the cam sprocket mark with the witness mark on the head, the crank mark was about 45 degrees off, but that's the way it was when i pulled the housing cover off. The belt hadn't stretched that much or there wasn't enough play for it to jump a tooth or two and watching the piston thru the spark plug hole, i knew piston was at TDC while the crank's marker was showing it about 45 degrees off - i figure the little sprocket washer with the crankshaft's mark had to have been mis-applied during original assembly - and again, the surging didn't start untill the end of the 2.5 hour cut session. Surging also does not start until the engine is fully warmed up - while i didn't race it to full rpm while warming up, after a minute or two of running, i took it to 2000 rpm and no surge - until it reaches full operating temp.
2) changed the oil in the hydrostat transmission - per honda svc manual spec, used 10-40W motor oil
3) Valves were also adjusted (first time in 20 years, and boy did it make a difference idling - much much smoother now).
4) Cleaned the fuel filter (back flushed), and I've been running some Chevron Techron fuel injector cleaner thru the engine, adding a couple ounces to every fuel tank fill up, to clean out the carb - stuff does wonders on injectors and is meant to be added thru the tank. But i just noticed the float on the carb, from pictures on ebay, appears to be some sort of plastic/foam item so i'm thinking next item to check would be the carb float to see if the Chevron Techron might have melted or affected the float.
any ideas or suggestions on this would be sorely appreciated.
and i've got one tip i'll post in a second thread about the clutch delay that a lot of posters on this board have mentioned - it had me scratching my head until i picked up a svc manual
i've got a Honda HT3813 that i've had since new, 1990 and absolutely love it
I ran it for about 12 years before putting it in mothballs and just recently took it out and have gone thru it getting it back in shape for full time service. In fact i like it so much, i just bought a clunker off egay to have for spare parts.
just finished changing the timing belt, wasn't a big deal as i used to mechanic back in the 60s & early 70s at Datsun/Nissan & BMW dealership.
Problem that's just surfaced, i was cutting the grass (about a 2 acre yard) and toward the end it started surging kind of oddly - kind of a sudden loss of power for maybe a 1/10th of a second where rpm drop off then it quickly comes back.
I had remembered seeing a couple of postings on orphaned chat threads that i'd googled back in the spring, about thrust washer/bushing svc bulletin for the hydrostat transmission honda apparently had put out, but for some reason google isn't pulling those same threads up again.
But any assist on this is appreciated - the surging occurs whether the LT is in gear and roll, with or without blades turning, and even if sitting still on level ground. It starts to surge about 2200 rpm and becomes real pronounced around 3000 - 3400 rpm. It sure sounds/feels like fuel or electric, and i can't imagine how a bushing in the transmission could cause it when the tractor is sitting still, but that drive shaft is live or solid connection with the flywheel.
I did check the governor adjustment, per the svc manual, and it was spot on.
some history on svc performed past few months -
1) new timing belt was just installed - i was real careful lining the cam sprocket mark with the witness mark on the head, the crank mark was about 45 degrees off, but that's the way it was when i pulled the housing cover off. The belt hadn't stretched that much or there wasn't enough play for it to jump a tooth or two and watching the piston thru the spark plug hole, i knew piston was at TDC while the crank's marker was showing it about 45 degrees off - i figure the little sprocket washer with the crankshaft's mark had to have been mis-applied during original assembly - and again, the surging didn't start untill the end of the 2.5 hour cut session. Surging also does not start until the engine is fully warmed up - while i didn't race it to full rpm while warming up, after a minute or two of running, i took it to 2000 rpm and no surge - until it reaches full operating temp.
2) changed the oil in the hydrostat transmission - per honda svc manual spec, used 10-40W motor oil
3) Valves were also adjusted (first time in 20 years, and boy did it make a difference idling - much much smoother now).
4) Cleaned the fuel filter (back flushed), and I've been running some Chevron Techron fuel injector cleaner thru the engine, adding a couple ounces to every fuel tank fill up, to clean out the carb - stuff does wonders on injectors and is meant to be added thru the tank. But i just noticed the float on the carb, from pictures on ebay, appears to be some sort of plastic/foam item so i'm thinking next item to check would be the carb float to see if the Chevron Techron might have melted or affected the float.
any ideas or suggestions on this would be sorely appreciated.
and i've got one tip i'll post in a second thread about the clutch delay that a lot of posters on this board have mentioned - it had me scratching my head until i picked up a svc manual
