Slow 2017 HiSun Strike 250

[joewinsor]

On 3/11/2018 at 2:32 PM, strike250 said:

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

Hi Matt. I have been reading this thread and I think I have a similar issue. 

I bought a new HISUN HS400 EFI recently. Still in break-in period with about 15 miles on it. This thing starts and runs just fine, like new, but at about 12mph it sputters/stumbles/boggs and does not want to go any faster than 12MPH. 
Does not sputter in neutral and revs very well in Neutral. 
Any thoughts on what is wrong?

[strike250]

I have a question about your HS400. when you are driving it, do you have the seat belt connected? Just wondering because it can effect the speed limit. I would go to the back of the seat belt connection located when you lift the bed up, you will see the light grey connector. Unplug the electronic connector for the seat belt and try it again. See what happens.

[joewinsor]

30 minutes ago, strike250 said:

I have a question about your HS400. when you are driving it, do you have the seat belt connected? Just wondering because it can effect the speed limit. I would go to the back of the seat belt connection located when you lift the bed up, you will see the light grey connector. Unplug the electronic connector for the seat belt and try it again. See what happens.

Yep!  Dummy me. If I was a safe driver and wore my seatbelt I would have already solved this, LOL.  

After I read your suggestion, I simply took a ride with my seatbelt on. Problem fixed, goes as fast as I need now.  For the heck of it, I did unplug the wire and it lets the vehicle go full speed.  So, to recap, apparently there is a speed limiter with the seatbelt indicator.

Thanks for the tip Matt. 

[joewinsor]

Another separate issue is the gas gauge shows 1/4 tank when it's full.  Any thoughts Matt? Anyone?

[strike250]

The fuel tank sending unit is not to hard to locate. it should be under the seat area. There should be a connector that takes the signal from the sending unit to the gauge. Check to make sure the connector is properly connected first. Then you can measure the resistance from the connector. It would be helpful to have the fuel tank sending unit out of the fuel tank. It is part of the fuel pump assembly. Remove the plastic ring securing it in the fuel tank. Pull it up and out easy, Now you can slowly push up on the fuel tank sending unit and watch the gauge to make sure it responds correctly. If not, then measure the resistance in the wiring. If it does not meet the OEM specifications, then the sending unit is faulty. If it is good, then you will need to check the connections to the gauge. If everything is good at this point, and you are getting the correct signal all the way to the gauge, then the gauge is faulty.

 

[strike250]

Here is a great video showing how to test any fuel tank sending unit. Pretty simple, don't worry about the color of the wires in the video, but the process is the same.

 

[joewinsor]

Great! Thank you Matt.  Probably wont get to it until the weekend. I will let you know. thanks, Joe

[strike250]

No problem, call me if you have any problems.  Here's a pic of what you might come across. The fuel tank will have two connectors, one is for the fuel pump and the other is for the fuel tank sending unit. You will know when you test it which one it is. But by lifting on the plastic float, you will see the Ohm meter rise and fall. Or it might just be stuck or sticking on something? Moving it by hand might fix it. who knows..................

 

[joewinsor]

That looks exactly like mine. Doesn't make sense the fuel gage does not work. I'm guessing float must be stuck. I did check it out briefly this evening. Plug on pump looks good. I have to get a tool to remove retainer, but I tried fishing a coat hanger thru filler into tank thinking I might poke free a stuck float but nothing happened. I can't believe the digital gage would be bad. It's a brand new UTV. 

 

[DigitalDan]

Are you absolutely positive that the tank is full?  I thought I was having the same problem with my 250 Sector when I first got it, until I filled it up to the point where gas was just about to start over flowing.  Then the gauge showed full.  

[CStrike250]

On 5/7/2018 at 9:17 AM, Fun Dad said:

Digital Dan,

Thanks for the reach out!  Yeah, did the same thing and am now able to get 8900 out of the machine per the gauge on the dash.  Definitely better, but like you say, you still bang up against the cutout at 8900 rpm, which is still only about giving me 36 mph on the speedo.  Much better than where we were, but still will be annoying on the roads, especially heading downhill.   It now seems that we are not loading the engine enough to keep it from banging up against the max rev limiter.  The obvious next step is to change the final gearing from 42 tooth final sprocket to a 40 tooth.  I am also planning on getting a 38 tooth as well.  The final gearing ration change should give us taller gearing and make it more tough for the engine to pull so strong to 8900 rpm.   Unless you beat me to it, i"ll let you know what I find with the gearing changes we are both making the exact same mods.  BTW - Matt at 250UTV.com (aka Strike 250 Advanced Member on this blog) has been incredibly helpful for me on this journey!  He is a Strike 250 Rock Star!!!  For those of you that are really trying to get their Strike 250 to shine, please visit his website at www.250UTV.com, he has got some real goodies for this machine..

Hey all, I am new to this. Would it be ideal to just buy this and put in a 36 or 40 tooth? Or send it to you Matt and have it reflashed? Dont need it to go 50mph but I would prefer to have the best launch and maybe 40 top end mph. 

 

Thoughts??

[strike250]

Hello, I would send in your ECU to me, let me flash it and also if your rear sprocket is a stock 42 tooth, I would go to 38-36 rear sprocket. The lower the rear tooth count will provide you with the higher top speed, the lower rear tooth count will give you quicker off the line.

[Tony Denunzio]

Hello, I am thinking about buying a 2018 hisun strike 250 for my son. Was told it will do 50 mph, but after reading all this I have my doubts. Has anyone compared this utv to the Polaris rzr 170? I am debating which one to get. We do a lot of desert riding, sand washes and rocks, and also glamis and dumont dunes. Any info would help, thanks 

tony 

[strike250]

Just checking in to see how things are going for you

[Tony Denunzio]

We are actually out with it right now in ocotillo. So far we love it. I do need to send you the ecu to reflash it, and I think it needs the lift kit for sure, it has already destroyed the plastic brake disc cover.  It already has 186 miles on it after the 1st trip, thank you for checking in on us, I want to do the exhaust also, in due time, but we are having a blast with it and I have been recommending it to all the  doubters and proving it is a great SXS for kids. 

[strike250]

Awesome! have fun with the family, send me some pics as well and I'll post them on the website.

[Tony Denunzio]

What email do I send the photos to?

[strike250]

[email protected]

[Mdeeps]

Has anybody done the sprocket change and or the ecu flash and can verify what mph you saw from the 38 or 36 tooth rear sprocket? 

[DigitalDan]

I'm curious about the same thing.  I haven't changed my rear sprocket yet.

[Mdeeps]

So I ordered the tuned and unlocked ecm today from the motorcycle doctor on eBay (great guy) and a 36 tooth sprocket from lance at sprocket specialists. (Also a great guy) I will let y’all know how it goes in the coming weeks

[Mdeeps]

On 9/24/2019 at 8:24 PM, DigitalDan said:

I'm curious about the same thing.  I haven't changed my rear sprocket yet.

Do you know what the new top speed is with just the tuner is? 

[DigitalDan]

On 9/27/2019 at 10:28 PM, Mdeeps said:

Do you know what the new top speed is with just the tuner is? 

It's a few MPH faster, but not very much. I think maybe 2 or 3 MPH. The change in peak RPM is very noticable though. Mine went from about 7800/8000 max to 9000 max.

[David Cordell]

Purchased a 2016 Striker 250 today. 317 miles and garage kept. Darn thing looks new. I would like to do the upgrades for top end. If anyone has a kit or part numbers I would appreciate it. I did screenshot the numbers for tranny shafts. Ecu is next.

Thanks 

David Cordell 

Edited June 1, 2021 by David Cordell
Misspelling

[strike250]

On your Strike, we can do things like port the cylinder head and we also have performance cam shafts. What is it you are trying to do, race, dunes, hill climb or just more performance? Most of the performance gains can be done through clutch mods and gearing.

[David Cordell]

Purchased a 2016 Striker 250 today. 317 miles and garage kept. Darn think looks new. I would like to do the upgrades for top end. I

On 6/1/2021 at 1:23 PM, strike250 said:

On your Strike, we can do things like port the cylinder head and we also have performance cam shafts. What is it you are trying to do, race, dunes, hill climb or just more performance? Most of the performance gains can be done through clutch mods and gearing.

f anyone has a kit or part numbers I would appreciate it. I did screenshot the numbers for tranny shafts. Ecu is next.

Thanks 

David Cordell 

[David Cordell]

Thank you for your answer.  I would like to change the ECU and rear sprocket. It's currently bone stock. 

I have another issue. I was driving it and it slowly quit as if running out of gas. Wasn't hot or out of gas. Weird thing was it wouldn't turn over unless the brake pedal was pushed. Man I bought it from just reached in a started it. Well after 30 minutes it cranked up. Can you point to a possible problem? Thanks in advance. 

[strike250]

There are no part numbers for the cylinder head porting or performance  camshaft. We have them here and exchange your parts. As for the stalling issue, I would check things like pick up coil. they fail at times and it normally happens when it gets hot. I would also check when it does stall for spark, and fuel delivery. the fuel pump should run for three to four seconds when the key is turned on then stop. when it dies, you would need to see if the coil is putting out spark to the spark plug. It takes three things to make an engine run, spark, compression and fuel. any one of those not working, and it will not run. As for the brake pedal pressed to run, that normally happens when its in gear. Make sure the transmission is in N before trying to start.

[David Cordell]

Good afternoon. I found the issue. One of the plugs that go to the fuse/relay box was loose. I used starting fluid a verified spark the redneck way. Lol. It ran. Started to check fuel pump and pulled seat and battery cover. With key on I tapped the top of the panel and the pump started. Started tinkering with wires and noticed I could hear clicking. Found the connector loose. Pulled it and re-seated it. Hasn't missed a beat since. Also explained why it wouldn't start in neutral with park brake set as those circuits run through that connector.  Sorry to be long winded. Just thought this might help others.