Likely to be a simple answer, but would like to get feedback if possible.
I have this mower, ran fine, then started running poorly (seeking), then wouldn't run continuously. Thinking it's probably just blocked fuel, I took the carby apart, cleaned it up good, blew compressed air through holes in carby, inspected seals/gaskets etc.. all looked good, no issues (engines fairly new, minimal use). Also blew compressed air through air filter. Air filter doesn't look too bad.
Put back together, starts, runs, but still seems to seek/pulsing. Not only that, on full throttle, it doesn't feel like it's running that fast (can't remember if it was doing this before though)
Questions;
1. Before I pull apart again, is there anything else that would cause the engine to seek/pulse besides poor airflow and/or poor fuel flow ?
2. What would cause the low revving, and is there a way to increase rpm ?
There have been reports of the Sprinter mowers surging and kicking back on starting due to the lightweight bar blade supplying an insufficient force to assist in starting and running like a blade plate normally does.
I would suggest blasting degreaser through all ports in the carb, remove the main jet and blast some up the non removable emulsion tube.
My sprinter does sound quite gutless when revved up (I only use it to pick up leaves of the lawn around the edges as it is small and nimble), but if it does need adjustment, undo the screw 2 inchs to the right of the fuel cap (in your video) and remove the vented plate, and you will see the governor spring. It attaches to the throttle butterfly at one end and the other to a metal tab - slightly bend the tab towards the front of the mower (gain spring tension) to make it rev a bit more - but don't go too fast and don't alter the spring itself in any way.
Might also replace the fuel line as it could be internally disintegrated and cause subsequent clogging.
Thanks Tyler, sorry got the delay in getting back to you.
Originally Posted by Tyler
There have been reports of the Sprinter mowers surging and kicking back on starting due to the lightweight bar blade supplying an insufficient force to assist in starting and running like a blade plate normally does.
I would suggest blasting degreaser through all ports in the carb, remove the main jet and blast some up the non removable emulsion tube.
My sprinter does sound quite gutless when revved up (I only use it to pick up leaves of the lawn around the edges as it is small and nimble), but if it does need adjustment, undo the screw 2 inchs to the right of the fuel cap (in your video) and remove the vented plate, and you will see the governor spring. It attaches to the throttle butterfly at one end and the other to a metal tab - slightly bend the tab towards the front of the mower (gain spring tension) to make it rev a bit more - but don't go too fast and don't alter the spring itself in any way.
Might also replace the fuel line as it could be internally disintegrated and cause subsequent clogging.
Regards Tyler[/quote]
Not sure about the 'Sprinter brand', but it's a B&S 190cc engine installed on a separate/spare mower base I had. The engine number is #12J902 - 1128 - 01 11092958 (see attached pics)
I used carb cleaner and sprayed through all the holes followed by compressed air, prior to reinstalling. Ill give it another shot in case I didn't get it all.
Re. the governor spring, Ill give that a shot, though not sure why it started being gutless, pretty sure it was running find in the past. Ill bend that tab and see how it goes.
I inspected the hose, still looks pretty good. Fuel flows freely, no probs. Ill give the other suggestions a shot, and see how it all goes, then report back.
I can't say that I have had a Quantam motor that hunts, but plenty of the Sprinters do it. I have swapped carbs around on these motors that hunted and nothing solved the problem. BTW, a Quantam on a little 16 inch base is a bit of overkill.
I have had a quantum that hunts on a masport base - xts 60. As its one of mine, I experimented and adding a thin sheet of foam (effectively a pre filter) made the problem much better.
Widget, I was just referring to the deck, not thinking that the engine wasn't original - normally they have a 450 with pulsaprime engine from the factory. Or the newer ones have the 125cc 300 OHV series.
Now that I see the top of that engine and that its an I/C, I get that it isn't the original engine. GMC used quantums on some of their cheaper models about 10 years ago, so I subconsciously didn't give it any more thought.
I have to agree with Norm that 190cc quantum is a bit overkill on a small deck, however I can understand that that may be intentional. I know a guy who lives on a rather large 'hobby farm' type property who only uses his push mower around the fence poles where the ride on can't get. He hates mowers with swing back blades (don't know why), but had a bit of trouble finding one with a bar, and an engine big enough to handle thick grass.
Make sure the jet is fully clean. Sometimes a wax like substance can coat these and cause a lean burn issue. Also replace the O-ring between the carburetor and intake tube.
As a last resort you can try increasing the jet size if you have micro drill bits available. Just be careful not to oversize as this lead to over rich condition.
