Raptor SD Won't Go Full Speed

BoylermanCT

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I mowed with my new Raptor SD for the first time today. Love the quality of the cut with the Oregon G5 blades. But the RSD did not seem much faster than my Craftsman tractor. My Craftsman claims forward speed of 5 mph, and the Hustler claims the RSD can do 7.5. So I was expecting to be zipping along 50% faster. I clocked the RSD at between 5.5 and 6.0 using my GPS. This was driving on a flat road, blades off, full throttle, drive bars all the way forward. My digital tach that I added shows 3590 rpms at full throttle.

I measured out a 200' section of road, and tomorrow will use a stop watch to time how long it takes to go the 200' and then convert that to mph to get a reliable number.

Is there an adjustment to get the mower to go the full 7.5 mph? I popped up the seat and saw a threaded rod attached to the ends of the control bars. Wondering if that is out of adjustment. I am bringing the RSD back to the dealer in a couple of days to have them put on the flex forks, engine guard and muffler shield, so I am going to talk to them about the issue. This is a deal breaker if they can't get it up to full speed.
 

BoylermanCT

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I timed several 200' runs, and was 23.0 seconds in one direction and 23.5 seconds in the other. This works out to 5.5 to 5.8 mph. My parts are in at the dealer, so I will be dropping off the mower to have them add the flex forks, engine guard and muffler shield and ask them to see if the forward speed can be adjusted up to 7.5 mph as 5.5 is not going to cut it!

If anyone knows if this is an adjustment, I would appreciate knowing. Thanks!
 

RhettWS

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Good afternoon,

Honestly, I have not clocked mine a but I suspect it goes about 7 or so. I suspect there is some adjustment as you indicated. Your dealer should be able to make that correction easy enough. The manual might indicate how to adjust that speed.

Mine certainly runs faster than the yard tractor I used to use. Any more speed would be a waste for me unless I wanted to race on the road. My yard is not super rough but not totally smooth either. There are a few spots where I can run wide open so to speak and it is zipping right along.

Others on the forum can probably tell you exactly what to adjust. Let us know what you find out.
 

kraky

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Ditto what Rhett said!
Just out of curiosity I wonder what the speed difference would be between running 8 PSI in your tires and running whatever the tires says max PSI? Just from watching tires move up and down from putting air in them I'll bet you're rolling radius could change a significant amount.
 

BoylermanCT

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I dropped the mower off and the dealer said there is a governor which controls the top speed and said it is a quick adjustment. When I pick it up on Saturday, I will have them show me where it is and I will share with everyone.

I'll double check the tires - I keep meaning to do that. They feel rock hard, so I am guessing they are over-inflated and I will need to bring them down to 10 psi or so.

Looking forward to trying out the flex forks. Will give an update on how those are too.
 

mhavanti

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Check your 20-50 motor oil in the hydraulics tank. If the hydros are not topped off in the pumps, it will not have full speed and will do damage to the pumps. Also, if the belt is slipping to the pump motors, it will not attain full speed.

Likelihood of either is slim, however, it can happen. All belts are not made equal and neither is all mowers. So, if the belt isn't getting a good grab on the drive pulleys, you get the idea.

Let us know how the governor adjustment works out.
 

BoylermanCT

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Got the RSD back from the dealer today. They put on the flex forks, muffler shield and engine guard, and adjusted the hydros to maximum pump output. It felt faster driving it in the parking lot, and GPS had it anywhere from 6.5 to 7.0 mph. When I got home, I made 4 passes on the 200' run, and did it in 20 seconds, so it works out to 6.8 mph. Fast enough for me, but it does make me wonder why it won't go 7.5 as the brochure claims. It could be the weight of the operator - I'm 265, so maybe it would be 0.7 mph faster with a 150 lb operator.

I did check the hydro overflow, and it has oil right to the cold line, so that shouldn't be the issue. I don't know how to detect belt slippage, there is no squealing or rubber smell. I have a friend who is a Deere mechanic, so I am going to talk to him. In looking at the hydros and the linkage to the control arms, I am wondering it I could lengthen the linkage to cause the lever on the hydro to move back further at full speed. The only thing to watch is that the hydros are not trying to move when at neutral.

So for now I am good! Thanks for all the suggestions.
 

kraky

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I always get a kick out of the "adults" they find to take pictures of for literature on smaller lawn tractors. I'm guessing the gals don't go over 90 pounds and the men probably 115..... gotta make those seats and operator stations look really big and comfortable like a Cadillac.
So...Possibly 90# operator....fully inflated tires, slightly downhill, 20 MPh tailwind......7.5 MPH....no problem! Lol.
 

577jersey

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Mine goes fast enough,,not sure how fast it goes but I hardly ever cut with it wide open,,most my lawns are a bit rough and I also like to take it a little easy on the residential mower..I have a couple flat lawns that I can hammer on..I will check my speed one of these days,,I know its fast enough for what im doing.

You being a big guy should have no effect on the speed unless you are going up steep hills cutting high grass,,then the motor might bog down a few hundred R,s.

My guess is its going 7 mph easy...I would have to run along side it to keep up.

Tom
 

mhavanti

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Tom,

Stop running alongside the Raptor. lol. Easier way to check the speed. Calculous works wonderfully. Distance divided by elapsed time, then multiply by the constant.

Example: 5280 feet
/ 21.67 Seconds
= 243.6548223350254 ....
X .681818
= 166.1282436548223 MPH My old Ranchero speed in a flying mile at 8500 RPM.

Lets say you choose to use 100 feet as your test distance and it covers that distance in say, 9.01 seconds.

My RSD : 100 Feet
/ 9.01 Seconds
= 11.09877913429523
X .681818
= 7.567347...........MPH

One of these days, I may tweak a bunch of things to move it along. It once was doing 8. So, I need to check the bugger out.

Ya'll enjoy checking your land speed.
 
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