HONGDOU GY 125cc HELP & ADVICE

Reevezie · Derestricted Danger Joined: 28 May 2009 Karma :

Hello everyone, i am new to the site and i have recently purchased a HONGDOU GY 125cc 4 stroke and was wondering if anyone else had one or had any info on them? The bike is a nice looking bike, i have started as i mean to go on by checking the bike over and all seems fine. Only snag i have is that it is very slow acceleration! I understand it only a 125cc and its 4 stroke but i heard other people claim there's is nippy, so either someone is telling porkies or theres summin wrong with mine? Can anyone help. is there anything i can do to speed it up abit? is there a restriction on the engine i can remove?

Any help or advice would be appreciated, thankyou..... Laughing

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C.B.T Passed: May 09 / Theory Passed: May 09 / Full Test Here I Come!!!

Currently: Hongdou GY125.....Hmmm?

gavcarter · Could Be A Chat Bot Joined: 28 Mar 2009 Karma :

No restrictions on the engine, or in the exhaust or anywhere on the bike at all. Any "tuning" parts you want to fit will have to be home-brew or doctored, you cannot buy anything for them that will improve performance other than decent tyres.

Reevezie · Derestricted Danger Joined: 28 May 2009 Karma :

Great stuff!!! Am gutted now because this bike is quite slow, hmmmm can i not change anything at all that will improve performance? Do you know of any parts from other bike ect that fit?
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C.B.T Passed: May 09 / Theory Passed: May 09 / Full Test Here I Come!!!

Currently: Hongdou GY125.....Hmmm?

djsalt · Derestricted Danger Joined: 28 May 2009 Karma :

what do you mean by 'sluggish'? It should be fairly quick up to 40mph then it will probably start to tail off.

Checked you spark plugs, air filter and HT leads are all well. Does it tickover well. Any more info might help others help you.

Cheers

Dave

Reevezie · Derestricted Danger Joined: 28 May 2009 Karma :

Yeh your right i should give more info, sorry. I bought the bike last week, i bought it off my boss at work (who also is my friend) lol, i went to look at it first of all, lovely looking bike ect, he is the second owner, i know the person who had it new he just used it to and from work but i dont think he is the type to get his hands dirty if you know what i mean, it now has only 1400miles on clock. He told me the bike hadn't been started for about a month, it did start with choke on but wasn't keen on ticking over at first until it warmed up abit. When i say sluggish i sort of mean it felt like i was on a 50cc scooter but with the added weight of this bike lol. Seemed to take along time to accelerate, i recently did my c.b.t on a chinese import 125cc, not sure of the make but simular size bike and that was alot nippier. I havent actually got the bike as of yet, the deal was he would put an m.o.t on it for me first as i wanted to be sure there was nothing serious wrong with it, the bike is in mint condition ect but just seems to lack abit of effort even for a 125cc, seemed like it was struddling, like it was pulling too much weight ( i am only 13 stone lol). When i do finaly get the bike i am gunna change spark plug, oil, air filter ect. I had alot of bikes as a child and used to know abit about tinkering with them but i forgot alot of what i knew, so if im gunna change anything i would rather buy good stuff to try and improve the bike if i can.......... Very Happy

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C.B.T Passed: May 09 / Theory Passed: May 09 / Full Test Here I Come!!!

Currently: Hongdou GY125.....Hmmm?

gavcarter · Could Be A Chat Bot Joined: 28 Mar 2009 Karma :

well you've just listed about all you can do without modifying parts from other bikes....

Reevezie · Derestricted Danger Joined: 28 May 2009 Karma :

Im hoping it is just running alittle sluggish as it hasn't been run for a while? do you think that could have something to do with it? I know its never gunna be a flying machine but i just thought there could be a few little things to improve, someone mentioned to me about changing sprocket size??? Question

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C.B.T Passed: May 09 / Theory Passed: May 09 / Full Test Here I Come!!!

Currently: Hongdou GY125.....Hmmm?

Reevezie · Derestricted Danger Joined: 28 May 2009 Karma :

Do you know what the engine is a copy of in this bike (HONGDOU GY 125cc) alot of people said its a Honda CG engine???
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C.B.T Passed: May 09 / Theory Passed: May 09 / Full Test Here I Come!!!

Currently: Hongdou GY125.....Hmmm?

gavcarter · Could Be A Chat Bot Joined: 28 Mar 2009 Karma :

Yes if you can find sprockets to fit that can help, but you need the bike running right first before you start playing with the gearing. Once you get it and check everything over and clean it up it should be better....

Reevezie · Derestricted Danger Joined: 28 May 2009 Karma :

Yeh thanks, now i found this little forum, once i get the bike running as it should so to speak lol i can mither all you lot for other info then can't i Dance!

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C.B.T Passed: May 09 / Theory Passed: May 09 / Full Test Here I Come!!!

Currently: Hongdou GY125.....Hmmm?

MaybeGuy · Super Spammer Joined: 12 Mar 2007 Karma :

how much are you/did you pay for it? because i hope you realise they are ~£300 brand new
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Blue_SV650S wrote: it was a sh1te wheelie, but it proves that he can get it up in 3rd and can do angles. In summery, mattsprattuk is a gobby little sh1tebag, dopehead tw4t, but sadly for all of us, he probably isn't THAT full of sh1te!! Mr. Green

Kickstart wrote: Hi I tend to agree with Matt. All the best Keith

Reevezie · Derestricted Danger Joined: 28 May 2009 Karma :

Hello matt, i agreed £200 providing it goes through M.O.T for it which i thought was quite reasonable, only using it just to learn alittle did my bike theory tuesday just gone and passed Very Happy

so hopefully i shall pass my full test soon and get summin decent. As for £300 i never seen them so cheap, think cheapest i seen is £600
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C.B.T Passed: May 09 / Theory Passed: May 09 / Full Test Here I Come!!!

Currently: Hongdou GY125.....Hmmm?

cyberglass · World Chat Champion Joined: 28 Jun 2005 Karma :

Had one a while back in black the speed issue you talk about is normal they are very slow and your lucky to get to 50 ragging the balls off it.

Bit of advice pull the seat off and wrap the cables from the battery in lots of tape as they rub through and blow the fuse which can become a pain in the ass.
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DL650 Vstrom 2004
DRZ400S 2003
Yamaha R1 2005

Reevezie · Derestricted Danger Joined: 28 May 2009 Karma :

---- · World Chat Champion Joined: 29 Sep 2006 Karma :

Mine did'nt seem too slow tbh.
I ended up changing the sprockets as it was only doing 45-50mph flat out.This got it upto about 70mph (indicated)

Then again,once my engine blew up after 800 miles Shocked

i rebuilt it and it felt like it had a bit more pull,not much though.

As has been said,make sure you look over it well (i'd advise lots of threadlock over everything)

Dave
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DRZ-400sm

stirlinggaz · World Chat Champion Joined: 22 Jul 2007 Karma :

hi,
having owned 2 of these, i can state with fact....they are shite. lol
only kidding (well not really, but there cheap)
but they CAN be made to go faster.
change the main jet in the carb (think its a 115 but i will check on that)
they are set to run ridiculously rich.
remove the bloody big airbox & fit a conical mesh air filter. (k&n or sb type)
then onto sprockets.
seen these fitted with all sorts of sprocket combinations.
another good mod is the 29mm mikuni carb, bolts straight on & is far better quality than the chinese copy fitted as standard.
seen these bikes get 65+ (& that is frightening)
saying that, with the standard brakes & rock solid tyres, your taking your life in your hands going over 50, especially if its raining, lol
some good advice to be had over on chinesebikeforum.
cheers,
GAZ

Reevezie · Derestricted Danger Joined: 28 May 2009 Karma :

Thankyou for all your advice, im going to change all the main components, carb, decent brakes, oil plugs, filter ect and hopefully try and spruce it up alittle, could you find out on the carb for me please..... Razz

____________________
C.B.T Passed: May 09 / Theory Passed: May 09 / Full Test Here I Come!!!

Currently: Hongdou GY125.....Hmmm?

Reevezie · Derestricted Danger Joined: 28 May 2009 Karma :

stirlinggaz · World Chat Champion Joined: 22 Jul 2007 Karma :

hi,
threadlok is in a little tube, like glue.applied to the threads of nuts,bolts etc.
ESSENTIAL for all the external nuts,bolts & fastners.
because the bike rattles so much, these rattle loose & fall off, lol
your as well replacing the bolts whilst your at it, as there usually an exclusive to china, special alloy of cheese & coke tins which snap as soon as you shout at them.
a couple of quids worth of decent bolts from any hardware store will do the trick.
the carb you want is the mikuni 29mm, available from scooter assasins (be warned they take ages to ship).
available from the same place is the filter & jet kit (which makes a big difference for little money).
if your looking for the carb, just type in gy125 carb or mikuni replacement carb into ebay.
cheers,
GAZ

Reevezie · Derestricted Danger Joined: 28 May 2009 Karma :

Thankyou for that, i am going to replace the bolts, heard quite alot about cheap bolts being used, i have a goods hardware store 3 streets from me, he does high quality stuff gunna change them all. As for the carb, i do wanna change it, i shall look for the one you said, thanks alot, is this carb any use to me, someone already suggested this to me?-

https://xian.west-wire.co.uk/index.php?act=viewProd&productId=8

They claim to be better than Mikuni???
____________________
C.B.T Passed: May 09 / Theory Passed: May 09 / Full Test Here I Come!!!

Currently: Hongdou GY125.....Hmmm?

stirlinggaz · World Chat Champion Joined: 22 Jul 2007 Karma :

hi,
i havnt looked at the carb in the link, but i can tell you it WILL fit, lol
xian racing is run by a guy who's active on the chinesebikeforum.
started up his own business selling stuff for tuning chinese bikes after getting frustrated at the lack of spares available.
guys fairly knowledgeable about these engines/bikes in particular having owned & tuned them fairly successfully.
hes good for replacement chains,sprockets etc & will be cheaper than most places.
& hes honest enough to tell you to buy elsewhere if he cant sell it as cheap!
for advice ask to speak to gareth.
after following his advice, i managed to increase the speed of my mates gy125.
cheers,
GAZ

rockers · Scooby Slapper Joined: 29 May 2008 Karma :

fiddle with the gearing, with my kymco stryker a 125 4 storke i went down two teeth and flat out down a hill proberly about to blow up Razz

i got 75 maybe little more, but i could go at 60 cruise easy.

prawny1 · World Chat Champion Joined: 28 Jun 2005 Karma :

If you haven't handed over any cash, walk away and buy something that you feel is running as it should from the start.

otherwise you may end up being unhappy with the bike and potentialy spend a lot of money if something is found to be seriously wrong,

Unless that is, the bike is going for a song and you think there is a chance of getting a cheap bike with room for repair costs.

d-bug · Renault 5 Driver Joined: 13 Jan 2009 Karma :

hi just reading though this lot , and you say about doing your test , really mate i wouldn't even bother spending time and money on carbs and more just to get those few extra MPH's out of it , i would put the money into your test and then your bigger bike , but then thats just me Very Happy

billyboy · Borekit Bruiser Joined: 27 May 2009 Karma :

hi mate if was you i would go with D bug,s advise do your test and get a bigger bike