XUV 550 Honda Engine Conversion

[Dane]

I made up a new throttle cable and have been driving the Gator a lot to shake out any bugs and I've been comparing it's performance to the original Briggs engine. Top speed is basically unchanged. With my Carlisle All Trail tires top speed on level ground is 29 at 4'100 rpm. The big difference is when climbing hills.

My road crosses a river valley a couple miles from home. With the Briggs engine and the pedal to the floor at the bottom and entering the hill at 29mph the speed would soon bleed to about 20 for much of the climb out of the valley. With the new engine I started at the bottom at 25mph and 3'700 rpm and the speed held steady for the climb. I could tell the governor had opened the carburetor but the engine has the power to maintain speed. I've not tried it yet with the pedal to the floor.

So far it seems that idling and short trips are not an issue for the Honda. The exhaust smells as it should, not excessively rich and the oil smells like oil and with no gas smell and the plugs look good. After idling several minutes you can stomp on the throttle and it accelerates smartly without hesitating or missing. I swear Deere would have had a real winner if they had put this engine in the 550.

[MBDiagMan]

Outstanding project Dane. How many hours did you get from the original B&S engine?

[DIXIEDOG]

Impressive conversion

[Dane]

I am loving the new engine. Last night I needed some working light and the Gator was the mobile lighting platform. I turned on all my forward lights (LED's) and let it idle for an hour and a half. It never missed a beat and never gave any indication that it was loading up or fowling.

[Bunky]

Good to hear. You have to use the tools you have -- loader on the tractor and the Gator for lighting.

[MBDiagMan]

Yeah, how did we manage to gut a deer that we killed at Sunrise before Gator's and Front End Loaders? Dane, is the deer season already in full swing there or is this a kill in the archery season?

[Dane]

NC is divided into regions and I'm in the central which is currently archery only. Gun season will not open here until mid November. Normally I'd wait for gun season but wifey was in a panic last week when she realized we were out of venison. Tons of alligator and hog but no deer so I had to get to work a little earlier than I had planned.

[MBDiagMan]

That's about the same schedule as the season in Texas. My lovely wife isn't big on cooking game. Her mother was an absolute master at it, but we lost her in 1998. My meat hunting pretty much stopped at that point.

[Dane]

Now it's perfect!

The engine came with governor and linkage system for a pressure washer or cement mixer. It worked reliably but not the best throttle control for a vehicle requiring frequent, precise throttle inputs. The Honda has a double bellcrank system (if you count the governor) which creates a long, circuitous throttle control path, lots of springs and linkages. The linkages and springs provide easy starting and low idle once running but are a bugger when driving around. The bellcrank has a simple steel on steel pivot which is slightly "sticky" for vehicle use. Add in the governor lag and it was not the best driving experience.

I finally broke down and brought the Gator back into the shop and shit canned the stock linkages. I replaced the Gator's stock throttle cable with a Teflon lined auto throttle cable. While it's larger in diameter than the Deere cable it's smooth as butter. Made a control arm to convert the longer throw (cable pull) of the gas pedal to the shorter motion of the carburetor's throttle arm complete with proper bearings at the pivot for smooth long term operation.

Now, the throttle response is much more auto like. No governor, bellcrank and multiple springs mucking between the gas pedal and throttle. Just a nice, butter smooth throttle response.

The trade off? The system on the Honda engine provided adjustment for easy starting. There were two adjustments that allowed you to briefly have one idle position during starting and another after the engine was running. After my mod I've only got a simple idle speed adjustment on the throttle butterfly. It works once the engine is running but I think during winter it will require a tap of the throttle when starting.

[Bunky]

Persistence pays off. It sounds like a great set up.