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800 watt chinese 2 stroke generator surging/hunting

redding

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hello smokstakers,I know most of you guys(and gals)on this forum don't have to many good things to say about chinese gensets in general and niether do I but none the less I have 2 of the little 800 watt 2 stroke generators(harbor freight/united power)make tho all these are pretty much the same no matter the maker,I picked them up cheap and tho I don't recomend relying on using these for emergency backup they are handy for running a power tool or a light in places you can't get other machines in(up and down a ladder one handed comes to mind)that being said I'm having a strange issue with one of them hunting/ surging,whats odd about it is that it only seems to do it when certain wattages are loaded,the thing starts surging right around the 400 watt mark and again around 700 watt and when it's idle with no load,everything in between seemsto be okay,I know a dirty carb will do this,usually this problem cause's the machine to hunt/surge no matter what kind of load is on it(or not on it),I've been thinking about rigging up a manual throttle for it so it will stay put,this way I could manually set the thing for a certain output according to what I would be using
 

redding

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after finding the service manual looks like the problem may be the flyweight governor,the carb is clean and my fuel mix is spot on so I've ruled that out,looks like its time to tear this thing down
 

Motormowers

Subscriber
Age
55
Last Subscription Date
07/13/2019
I have one of those generators and to correct mine I ran a torch tip cleaner through the jets a couple of times to clean any build up of varnish or corrosion and it worked great. These are run pretty lean as it is so I may have enlarged the jet size slightly for more fuel. Seems to like it and not run as hot. I also only use Stihl synthetic oil in it. Great portable generator for basic stuff where no power source is but agreed I wouldnt want to rely on it. They also dont like running several hours straight either I found out.
 

jcarter

Registered
I agree with Motomowers. A common cause of surging is a lean air fuel mixture in the idle circuit. At governed speed with no load the carb is actually running on the idle circuit, not the hi speed. Many of these small engines come out of the factory set too lean, probably an attempt to adhere to emissions standards. I have a set of drills from #60 to #80 that I use to enlarge the idle jet until the hunting stops. Does it still hunt when you put a load on it or does it smooth out? You may have a governor or governor spring issue but I suspect the problem will be in the carb.
 

redding

Registered
Does it still hunt when you put a load on it or does it smooth out? You may have a governor or governor spring issue but I suspect the problem will be in the carb.
its odd it only surges when either round a 400 watt or 700 watt load is on it,I would tend to think it would surge no matter what the load is if the problem were with the carb but I'm not ruling that out,not by a long shot,I cleaned the carb but I will do as suggested,I have not tried moving the governor linkage spring into another slot(it has 3 or 4 holes)maybe this will help,thanks for all the replies:wave:

They also dont like running several hours straight either I found out.
Any theories as to why??
 

Ed Sparks

In Memory Of
Last Subscription Date
06/28/2015
designed to last twenty five hours total.
if they run too long the parts expand and seize:shrug:

what do you expect for a machine that retails for a hundred $$ after traveling halfway around the globe:brows:
 

redding

Registered
designed to last twenty five hours total.
if they run too long the parts expand and seize:shrug:

what do you expect for a machine that retails for a hundred $$ after traveling halfway around the globe:brows:
good greif:( but can't say that wasn't the first impression that crossed my mind when the carb mount holes stripped out completley after only 3 passes and babied it at that,had to use helicoils and stainless to fix it,is it mostly the poor quality aluminum that expands/contracts? or is the cast iron internals of the same caliber?

btw ed,do you think the yamaha ET650/950 which is what these cheapies are cloned from have the same build quality?I've never seen one in real life to be able to compare the two

also,does anyone make somthing this light in and around the same wattage that isn't a piece of crap?:shrug:
 

YellowLister

Subscriber
Last Subscription Date
o9/30/2019
sometimes you can find older 600 to1000 watt kawasaki powered or honda gens for a good price. there heavier.. around 50 pounds or more but built pretty good and will last if you always keep the oil clean and full.
 

Fred M.

Registered
also,does anyone make somthing this light in and around the same wattage that isn't a piece of crap?:shrug:
Redding-

My 57 pound Honda EX-1000 was a bit more than I could easily carry, so I got a Yamaha EF1000iS inverter generator. It is rated at 27.9 pounds dry weight. I do not know how that compares with yours.

I chose the Yamaha over the similar Honda because it appeared to have better specs in weight, gas tank size and noise level. It is a nice generator, but Yamaha uses a different method of rating noise level! It is not loud, but Honda has it beat.

Fred
 

redding

Registered
until the hyped up prices for inverter generators level out I doubt I'd be buying a new one,used is a different story,its a sad state of affairs when no matter what you buy new these days is pretty much all made in china,this is some scary stuff,deppressing:(:(
 

redding

Registered
althought these machines are not without there weaknesses I can't help but take into account that there's to many people that have claimed these have lasted them for hundreds even a few bold statements of a thousands of hours and many years,everybody can't be telling a tall tale
 

redding

Registered
I got around to trying some of the different slots in the governor linkage today and putting the tension spring in the outermost slot(most tension)solved my hunting/surging issue,I think where it was in the middle had to much play and kinda got hung up in a segway for lack of a better term,hope it stays put for a while
 

len k

Subscriber
Last Subscription Date
12/12/2018
Many engines have a small spring that keeps tension between rod and arm with hole in it, to eliminate slop from big hole. It is usually wound over the rod and attaches to arm at both ends of rod, keeps a slight preload on mechanism to avoid all play.

I had a rototiller engine that would hunt all the time, then I read Onan manual and learned about it. I looked at rototiller engine, saw it disconnected, I connected it and all hunting stopped.
 

richard.bessey

Registered
Hunting problems, in my experience its been caused by fuel starvation problems.
If you pull the fuel line off the carb, do you get a good flow of fuel?
I did this on my genset when it was hunting, was only getting a slow drip, just barely enough to keep it runnin.
 

3VO

Registered
The chinese use poor quality springs that stretch out on HF engines.

The gov spring on the rod that goes to the carb become too weak and the engines hunt. I fixed my neighbors log splitter by putting a square S bend in the spring with a needle nose.
 

redding

Registered
:wave:while I was trying different holes the gas tank was removed and I used a syringe to inject gas thru the hose to keep it running,the pressure from me pushing it thru may have caused it to get proper fuel amount so I'll try it again today with the tank on and check the fuel line for proper clearence,thanks for pointing that out

a previous poster brought up the point of the holes in the jets/needles of the carbs on these little 2 strokes being to narrow to get proper amount of fuel to run right so he widended them by drilling them out,this definatley would be the way to go
 

Ed Sparks

In Memory Of
Last Subscription Date
06/28/2015
The chinese use poor quality springs that stretch out on HF engines.

Corrected it for you:D


The chinese use poor quality EVERYTHING when building crap to export to North America.:brows:


Yet some folks keep buying it.:shrug:
 

3VO

Registered
Corrected it for you:D


The chinese use poor quality EVERYTHING when building crap to export to North America.:brows:


Yet some folks keep buying it.:shrug:
And we are stupid enough to keep buying it.

Actually it is worse then that. Shipping all the jobs overseas has helped to ensure that chinese crap is all a lot of people can afford.
 
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