Predator rpm

To be Honest does anyone really want EFI? I sure dont want a go kart with efi...IMO. Our drag cars both still have carbs. My go kart motors all have carbs, not everyone has switched to EFI and I sure hope go karts dont go EFI that is an uneccasary cost to add to the already stupid amount that go kart motors cost.
 
I just dont agree. Motorcycles didnt raise dramatically when it was released. Automobiled didnt raise dramatically when it was released. Tractors didnt raise dramatically when it was released.

The trend could have been followed...years ago.
Good point . Though the price point is considerably different .
 
Didn't know these engines had rev limiters , just a gov . How many races are on this engine ? What has been done to it ? Valve springs ever been changed ? What mods does your rules allow ?
 
But what about the Honda, Briggs, Kohler, Tecumseh?? Why havent they went to EFI?? They are the only mass produced engines that still have carbs.
because these engines are made to run generators and power washers. these are far from racing motors. but also these motors don't have batteries or alternators its more cost than just the EFI throttle body and injector its a whole host of things that EFI needs to work properly.

to the original poster I have an engine that will run to 5000 on the stand and won't do 3500 on a dyno pulling a 500 lb wheel your valves are probably not sealing or the valve springs are floating . make sure your tank isn't too full and or too low is your cap vented? you might need to pull the head and lap the valves
 
I figured out what’s was wrong i tried moving the spring to every hole and had the same results. I had been setting the gov by the lever on the engine. There was so much play in the shaft where the lever swivels that it was rolling at full throttle and letting the gov spring go back just enough to gain 150 rpm. It doesn’t do that when I set it by the foot throttle because the throttle rod hooks up so close to where the lever swivels
 
Makes me wonder why these engines were not designed as fuel injected. even 2 stroke boat motors have be EFI for 15 years...motocross.

I wonder what the hold up is.

Sure would be nice to build a motor that makes wads of power, then put a 5k chip in the computer and gear it to do its job.
I agree! do it just like the LO206 and be done with it.
 
I have had about 15 HF hemi engines over the past few years and the free rev RPMs have all been between 53 to 53.5 K. I think I only ever had 1 engine that turned 55.6 K ON THE STAND so I turned it back to 54 just to be safe. We are winning races here in Pa. turning 47 to 48 K RPMs.... Some tech people may disagree but ,,RPM TECH should be done using the throttle pedal . ,,, that's the way it's raced . in fact it's illegal to use your hand to run the throttle while racing . all my motors work best turning 47 - 48 RPMs on the ground ,,,that's what the Dyno shows, and that's what we gear them for .
 

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Didn't think you could turn the same thing on the stand as you could on the track from what I have read. Someone said 5500 on the stand would. E around 4900 on the track. I don't know this for sure it's just what I have read. Any input.
 
Didn't think you could turn the same thing on the stand as you could on the track from what I have read. Someone said 5500 on the stand would. E around 4900 on the track. I don't know this for sure it's just what I have read. Any input.
Where it's set at on the stand has nothing to do with where it race's at on the track, your gearing dictates on track rpms. Set it 70 to 100 less than max on stand rule , and target 4800 rpm to race.
 
Was reading what jstwaser said about checking rpm on the stand. How do most tracks do it. Seems like you would do it with the accelerator. Put it to the floor and check it.
 
I have had about 15 HF hemi engines over the past few years and the free rev RPMs have all been between 53 to 53.5 K. I think I only ever had 1 engine that turned 55.6 K ON THE STAND so I turned it back to 54 just to be safe. We are winning races here in Pa. turning 47 to 48 K RPMs.... Some tech people may disagree but ,,RPM TECH should be done using the throttle pedal . ,,, that's the way it's raced . in fact it's illegal to use your hand to run the throttle while racing . all my motors work best turning 47 - 48 RPMs on the ground ,,,that's what the Dyno shows, and that's what we gear them for .
Is this 5300 to 5350 out if the box with the governor hooked up? When you say you turned it back did you do that with the throttle stop screw?
The track here is going to have a box stock class this year. I went and talked to the track owner today to see what he had to say about the rules. I was talking to him about the 5500rpm on the stand rule. He has two karts with basically box stock motors but he has the governor tied back
He has no tack on either one. I am wondering if it was put on the stand without a governor what would it turn? I believe the governor would have to be on to make it surge less than 5500.
He is trying to get his rules. Any suggestions on governor.
 
Was reading what jstwaser said about checking rpm on the stand. How do most tracks do it. Seems like you would do it with the accelerator. Put it to the floor and check it.
No it's on the stand governor is hooked up, what Johnny is saying is tech guy should push throttle foot pedal to check not work throttle arm on side of engine by hand so it's truly as raced.
 
Is this 5300 to 5350 out if the box with the governor hooked up? When you say you turned it back did you do that with the throttle stop screw?
The track here is going to have a box stock class this year. I went and talked to the track owner today to see what he had to say about the rules. I was talking to him about the 5500rpm on the stand rule. He has two karts with basically box stock motors but he has the governor tied back
He has no tack on either one. I am wondering if it was put on the stand without a governor what would it turn? I believe the governor would have to be on to make it surge less than 5500.
He is trying to get his rules. Any suggestions on governor.
Go to pennscreekracewaypark web site predator rules that's the only way to go, 7 stars and selinsgrove both follow those as well.
 
I’m running a box stock predator 5000 rpm rule it hits 4965 on the stand but I’m hitting the rev limiter at 4658 on the track. I was wanting to see what everyone else’s is hitting on the track vs on the stand.
Yeah Lol our track Jackson Speedway wants us to run at 5,400 RPM max with governor
 
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