Fun Dad

Slow 2017 HiSun Strike 250

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Guys,

I need some expert help..  I just bought a 2017 HiSUN Strike 250 and was real disappointed to find out that there is an electronic spark cut out at 30 mph.  Every article that I read prior to purchase said that the unit could hit 45-50 mph with the pedal stop screw removed.  Not the case with my machine.  Never bothered to ask the dealer before purchase, so it is my fault...  My guess is that HiSun got some flack about thier "kids" machine doing 50 mph and were forced to add the electronic limiter..  Can anyone verify that previous to the 2017 model that the machine can actually could do 45-50mph with the just pedal screw removed?  If so, what RPM is it at when doing 45-50 mph.  Maybe I can get an older version of the Delphi ECU, assuming that is where the spark cut out is located...?

The machine is definitly full featured, but as you all mention, needs to be gone over after purchase.  A-men to stipped screws, and if you suffer from a crazy squeak sound that sounds like chains dragging, check the torque on the suspension a-arms and shocks.  Ours were so tight, we could barley get them loose and the suspension would not move, essentially zero travel.  Once we lightened up the torque, greased the plastic bushings, and added blue threadlocker, the suspension actually worked and all the squeaks went away.  Also have same problem with the shift linkage rubbing on pipe and also pipe rubbing on chassis.. This weeks project!

Any help on the speed would be awesome!

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Hello there, there are a couple of things to address here. First off is to make sure when the throttle peddle pressed all the way down, that the throttle is also opening all the way. You can check this by removing the center cover. When you press down on the throttle, reach over to the butterfly valve and see if you can open the throttle any more on the throttle body. If so, adjust the throttle cable. But you need to make sure when the throttle is released that the throttle also closes as well. Meaning you will have just a little bit of slack in the throttle cable. You don't want the throttle body hanging up causing the engine to rev. After that, there is come control in the ECU, but there is also a electronic speed limiter, located under the dash by the winch control box. Try to make sure the throttle is adjusted properly first and let me know. Matt

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Matt, any luck with Flashing the ECU as of yet? It’s a Delphi so I assume any Delphi Diag. Shop should be able to adjust the settings. I know Harley uses the Delphi setup, and I know the support for Harley is crazy good. Let me know if Hisun got you hooked up yet. I’m heading to the Pink Coral sand dunes for spring break. Imperial Sand dunes went good as well.


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Yes, I am very close to making a public flash for the OEM ECU's. As for just taking it to a local Delphi shop, it's not that easy. Yes others like Harley use the Delphi MT05, but they use different language. It took me a while to gain access to the language needed to rewrite the ECU. But I finally got it and am working on making more power while still being reliable. I will make everyone aware when its done. But I want it done right. I will either have it available to purchase as a new ECU, or have the customer send me their ECU to remap. I'm thinking some will want to keep a stock ECU for one reason or another.

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Yes, I am very close to making a public flash for the OEM ECU's. As for just taking it to a local Delphi shop, it's not that easy. Yes others like Harley use the Delphi MT05, but they use different language. It took me a while to gain access to the language needed to rewrite the ECU. But I finally got it and am working on making more power while still being reliable. I will make everyone aware when its done. But I want it done right. I will either have it available to purchase as a new ECU, or have the customer send me their ECU to remap. I'm thinking some will want to keep a stock ECU for one reason or another.



Valid points. Yeah, let me know.


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Valid points. Yeah, let me know.


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Also, I noticed the 3 screws holding the spark arrest and exhaust cover/tip on the exhaust were completely stripped out and falling out. I removed them as well as the arrester, however the tapped threads were so stripped I can’t put it back. Any luck with a new exhaust being available as of yet?


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Just an update on the slow unit issue. I wanted to make sure I get back to everyone regarding the slow top speed on their Hisun 250's. After confirming with HiSUN, the 2017 and newer units have a different gearing inside the engine as well as a modified ECU. This was in response to customer feedback regarding top speed. Some customers were complaining about the units going too fast. So HiSUN changed some things to help control this. I am sure this is the new response from most manufactures now a days.  As no one wants to get sued or have legal issues. It has gotten to be a very liable state we live in now, and if just a few people complain about something, things get changed. I am working on new sprockets which should be here within a week. I am also working on the ECU and hopefully it will be done about the same time. I have yet to confirm if the old gearing will still be available or if it will automatically supersede to the new part number. I will keep everyone up to date on my website.

Matt

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I just purchased a new (5 miles on it) 2016 Sector 250 that has the same electronic spark cut-out at 7000 rpm / 30mph.  Ugh...  hate that sound.
The gauge's "red line" is 9500-10000, although I doubt that would be safe for the little engine that could...  What is the safest RPM these 250's can run?

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Hello there,

I know about the early cut out on the newer models. As for the RPM limit, I have seen the gauge and know it says a high RPM, but a few things come into play about that. First off is that most gauges show a higher than capable limit, in cars, truck, motorcycles and more. This is to give the illusion that the vehicle can go crazy with the RPM range. Reality is that most vehicles have a RPM limit below what the gauge actually says. This is for reasons of reliability and engine safety. The HiSUN is good till about 8000 or so RPM. Anything over that and the horsepower starts to fall.  On the newer ones the gearing is also changed. The rear sprocket is a 42, and used to be a 38. The spark cut out to limit the speed to around 30 can be changed with some ECU programming.  We are changing the rear sprockets to 40 and opening up the ECU and installing the tune of the 2015 ones. They seem to run pretty good with this configuration. When an engine revs too high, some things can happen. One of the most dangerous things is to have the valves float and that could lead to the valves hitting the piston causing damage. The second thing is the loss of power when it revs too high. the engine and cams can only produce power until a certain level, so all that noise will no nothing for more power, just make it sound like a buzz box. So again, the answer to your question is that it can safely rev up to about 8750. but the power really stops at around 8000. In these small engines, they really rely on torque, and that is produced down low anyhow. Since they only have about 12 to 15 hp stock, even with a race set up, it will go to about 20 ish. which means not a lot of hp to get these things moving. they really crave the torque to get them up and going, and that is produced at a lower RPM rather than a high one.

 

I hope this answers your question.

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I'm not trying to ring every ounce of speed out of the little 250.  If that was the case, I'd start by losing some weight, lol.

It's that electronic cut-out / stutter that drives me crazy.  If it only went 30mph, but sounded like it was running right, I probably wouldn't even bother.
It might be a different story if I line up against someone in a different Sector 250 and they dust me, but that won't happen, I don't think.

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