HS 142f bucks and cuts out when cruising
- Thread starter worksuxxx
- Start date
GearNut.. I agree with the plug gap. I thought I saw it posted at that gap somewhere and thought the same but tried it. I Just installed the NGK CR7HIX plug and left the gap alone. I talked with someone earlier today about my running problem, and he stated maybe I was running lean even though I thought I was running rich. I turned the air screw out pretty far and it seemed to be better, not perfect. I hooked up my tach and also found I am topping out at only 6600 rpm. It feels real low on power. Takes much longer to accel than any other bike so far. I am running 20:1 ratio so I know my gearing is good. I have done the valves at a not too tight .004 and .006. I also set the magneto gap using my drivers license, which I am now second guessing. I think with the license it is probably gapped between .012-.014. Thinking that may be too big of a gap.
Tonight I am going to try the valves at .00325 intake and .00525. Test ride and then change the gaps on the magneto an increment at a time to see the differences.
I have cleaned my low jet and main jet on the carburator, is there anything else that would need to be cleaned? Lets say for instance if one were to forget to clean the tank before starting, and without an inline fuel filter?
Tonight I am going to try the valves at .00325 intake and .00525. Test ride and then change the gaps on the magneto an increment at a time to see the differences.
I have cleaned my low jet and main jet on the carburator, is there anything else that would need to be cleaned? Lets say for instance if one were to forget to clean the tank before starting, and without an inline fuel filter?
Just ran the bike with new valve adjustment intake .0035 exhaust .0055. Ran better. Low rpm throttle was at least twice as good as before, and maintaining cruising speed without bucking back n forth was also about as good. Actually wanted to accelerate a little better also. Still not there by no means, but at least I am going in the right direction. Will try magneto gap settings before another valve adjustment.
Question about the NGK CR7HIX. It didn't have the cap that most plugs have. My spark plug boot actually came off the plug while riding. Am I suppose to put a cap on the top of it?
Question about the NGK CR7HIX. It didn't have the cap that most plugs have. My spark plug boot actually came off the plug while riding. Am I suppose to put a cap on the top of it?
Never try to gap an Iridium plug. They come pre gapped from the factory as it is all to easy to damage the tiny iridium tip if anyone tries to gap it themselves. You did good on leaving it alone.
The factory plug cap on the HS142 requires that the spark plug has the ferrule threaded on it's end.
If you have been running the plug without the ferrule installed all this time it's no wonder the engine has been running poorly. The electricity can still flow through the connection, but it will be arcing inside the boot (ruining the contacts) and arcing at the spark plug firing end as well. Double duty, poor performance, not reliable, will not work all the time.
The factory plug cap on the HS142 requires that the spark plug has the ferrule threaded on it's end.
If you have been running the plug without the ferrule installed all this time it's no wonder the engine has been running poorly. The electricity can still flow through the connection, but it will be arcing inside the boot (ruining the contacts) and arcing at the spark plug firing end as well. Double duty, poor performance, not reliable, will not work all the time.
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I did not gap the new plug. I knew not too. I simply stated the new plug did not come with a cap. I ran it last night for 5 minutes that way. Plug boot came off. I hadn't noticed it did not have the cap until then. I thought last night it had ran better after the valve adjustment, at least in a positive direction. Rode it again today but was actually pretty much the same. I don't have a clue what's wrong with this motor, I have tried different valve adjustments, magneto gap adjustments, plugs, Even swapped carb from running bike that I knew was good to no avail. Finally got ahold of a tech at gasbike about an hour ago. He agreed to swap both motors, but warned me that this new shipment of motors just came in the I got two from and I would be getting from same batch. I am crossing my fingers that the next two will run correctly. Only now I have to go to Fedex to ship these back. Not happy about the cost of shipping a product I originally paid for already that should have ran. I am probably out another $70 for shipping two motors. Anyhow, I have posted the serial #'s with manufacturing date in this thread. I hope no one else has these problems but if you do please indicate serial # for others to see. Just as a note, a buddy of mine owns a lawn mower repair shop, he spent hours on it yesterday and didn't have a clue.
Update.. Got two new replacement motors from Gasbike.net the other day. Unfortunately same build date as other two, so am a little worried after the experience with the first two motors. Installed first motor couple days ago. Does not buck or jerk, so much nicer while cruising. After two days of breaking the motor in a bit, I find I am unable to get motor to accel past 6500 rpm, even downhill. I have not made any adjustments to carb or valves yet. Putting on more miles to break it in before attempting any adjustments. I am hopeful after some adjustments I will see higher rpm capability. I will be installing engine number two today on the other bike, and try that one out tonight.
Well i went ahead and checked valve adjusdidderence. Tried 3 1/2 turns out still no difftment. Intake .006 exhaust .007. I set intake .004 exhaust .006. Acceleration was better. But same as last two motors, 6800 -6900 rpm starts cutting out like a rev limiter does on a car. Swutched stock plug with ngk irridium, still same. Adjusted carb from 1 1/2 turns to 2 1/2 turns out, no difference. Really wierd other two motors cut out at same rpm also. This motor at least runs good. Anybody have any ideas as to why motor wont rev past 6900 rpm?
Other than an intake or exhaust restriction, I have no suggestions to the "rev limiter" you are experiencing.
7000 RPM is pretty darned close to the max these engines can spin anyways. I wonder if the newest engines do actually have a rev limiting ignition?
7500 RPM is screaming them. 8000 RPM and the connecting rod fails.
Terry Blow has a video of himself over revving one and true to his name, the engine blows.
http://www.youtube.com/watch?v=hJmNXvjukdw&feature=related
7000 RPM is pretty darned close to the max these engines can spin anyways. I wonder if the newest engines do actually have a rev limiting ignition?
7500 RPM is screaming them. 8000 RPM and the connecting rod fails.
Terry Blow has a video of himself over revving one and true to his name, the engine blows.
http://www.youtube.com/watch?v=hJmNXvjukdw&feature=related
Yeah the last four engines I have gotten will not rev past 6900 rpm and that's downhill. My other recent motors all went to 8k. I am gonna order a kit from a dif vendor Monday and see what it does. All four of these engines were produced late march. Problem is I don't like 25 mph as my limit. Cruising is good but I occasionally like to hit that 30 mph mark.
Ok, 2nd engine kit didn't pan out so well. But it seems its just the carb. It will die out after running a short while, then fuel dumps out of the overflow tube. I am only 1 1/2 turns out. I checked the float needle, does not seem to have any obstruction to it. All jets are clean. I am not good with carbs, so I just ordered a new one to be done with it. It also cuts out when first giving it throttle. Put the good carb on it to try, runs good but still cuts out. Valves have been adjusted and I even tried changing the magneto. Hmmm, must be me. gonna have to look closely at this one. I even unhooked the kill switch wiring to the magneto to make sure that wasn't it. Doesn't buck and jerk like the other two previous motors that were replaced, and the cutting out is not nearly as bad, but still annoying. At least I got one running like a champ. I should get new carb Saturday, then once I eliminate that concern I will tackle the cutting out at low throttle. Both motors still do not accel past 6800-6900 rpm. And I don't know if its because I am trying to find a problem, but it seems the valve lash is noisier than my other motors. They both came adjusted at .006/.007. I have reset both to .004/.006. I even tried .0035/.0045. I can hear the valves on these but don't know what's normal, I never paid attention to it before.
Not true.
8000 rpm or a bit higher is no problem.
Redline is 7800 rpm.
Terry was running an under geared HS at 10,000 to 11,000 RPM when he blowed his motor up on that video.
The HS and Honda 50cc 4 strokes will run all day at 7000 rpm.
New carb corrected the problem on the one motor. Runsgood except cannt get past 6900 rpm. Gonna try a dif cdi on it tonight. The other motor I found cut out over bumps. Thought possibly was wiring. Turned out something in that carb. If I pull bike side to side it will die. Swapped with new carb..fixed it. So both carbs on these engine kits had a problem. One ran bad and kept dumping fuel out of the overflow and the other died or cut out over bumps. Side to side movement of bike engine would die. Word of advice to all huasheng kit buyers...look at build date if experiencing these problems. 3/25/2013 is the dates of my last 4 engines that did not run without a problem. Now I get to chase down the no revving past 6900 rpm. I have done valve adjustmens from .003/.004 thru .007/.011. Still at a loss. At first I was frustrated having to deal with these issues. Now I am hbappy to have gained as much knowledge I have troubleshooting these mistake motors.
Are you really sure that your 6900 rpm's is accurate?
Venice Motor Bikes has made manifolds to adapt the good old NT 2 stroke carb to the HS motors.
Venice Motor Bikes has made manifolds to adapt the good old NT 2 stroke carb to the HS motors.
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I believe so. Rpm guage pegs the idle rpm correctly. I have tonight. Off and plan on trying to gps my speed. I can then do the calculator. A friend came over last night on one of my previous builds and man that engine ran like a spotted ape. Went straight to 8k and pulled good. Unfortunately can't compare since it has the 4g 100t trans. The two I have now are t 80t version. But tonight I am borrowing the cdi off that motor to see if it makes a difference. I just don't see anything else that would make sense.
Doesn't have a brand name on it. Bikeberry.com just started selling the the one i have. I have used it in conjunction with bike speedo on other bikes and was spot on verifying with gear calculator. Not saying it couldnt have gone haywire since. I will either try gps or install bike speedo tonight, check speeds atainable and cross reference with gear calculator to verify accuracy. But goeat of pants feel and sound, i feel its not reaching its limit and lean towards the rpm as being correct.
I was having this exact same issue with 2 engines. As embarrassing as this is I was running with the choke on because I thought it was in the off position. Try running it with the choke at the halfway setting and see what it does. I know you mentioned you inadvertently ran other engines with the choke on but this sounds like what I just went through.
Well now that I have another good running bike I did a month ago to compare with... valve tap on these two motors are obvious. Different adjustments don't make a diference. Upn closer inspection I finally noticed something off. The exhaust valve does not seem to be working correctly. When I turn the flywheel I notice the valve opens and closes as if it were not a full stroke. I checked the good motor and found the exhaust valve opens and closes on a longer stroke equal to the intake valve. Wow. Bad cam?
or a bad lifter. I noticed in the exploded diagram of these engines that 1 cam operates both the intake and exhaust valves so if the intake valve is opening and closing properly then I wouldn't suspect the cam. I would think about the lifter and the rod.
Thanks. I didn't notice how bad the tap noise was on both these engines. I only noticed after hearing the other bike. Funny thing is, I just tried to swap out the coil from the good bike only to find the engine barely runs with that coil. Seems barely any accceleration and sounded like half as loud. Called gasbike to ask about this, was told to email don grube. I'm getting back to being frustrated with these two motors, and just about to order two motors from bikeberry.
