Hi, cheers for that advice...I checked the float level and fuel flow from the tank previously but I'll have another look at it and report back...this is starting to become a bit of a mystery to me!
L-Plate Rider
Hi, cheers for that advice...I checked the float level and fuel flow from the tank previously but I'll have another look at it and report back...this is starting to become a bit of a mystery to me!
Forum whore
maybe you shouldnt have a GN :P kidding haha
but it sounds like there is an optical illusion or something going on here! haha post updates!!
Originally Posted by nodrog
Fair weather rider
im having the same problem...around 3 - 3500rpm is when most of my splattering happens, and dont get me started on the mornings... i also need to have the choke on all day just to take off in 1st..... however, i can ride all day on the motorway with no problems...
when i first got it, it showed small signs of splattering but after 2 months, its a big problem all through the gears....
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Moped rider
No Its not bollocks, many new bikes suffer from this problem. The reason is the quantity of oxygen is the air in/around new zealand is greater and the air in asia and also cleaner. There are service scedules in place for some carby bikes that get carried out in the predelivery inspections so the problem is corrected before the customer gets the bike. This was put in place by Suzuki new Zealand, which just happens to be in my home town of wanganui.
I know this because i am a suzuki mechanic and i have done the chinese GN 250 modification myself many times. The VS650 is another one we have to change. Unfortunately this problem was not realised straight away so there are a few spluttering GNs out there.
Moped rider
I work for whitelock suzuki in wanganui, we have a jet drill we use, not sure of the exact size thou, ill try to find out tomorrow.
I have riden them before and after drilling the jet, from brand new, to see the difference. It is quite noticable. I found i had to rev it fairly high and ride the clutch quite a bit to get away in first before the mod.
Hardcore Biker
I have a smilar problem with my TU250. It started sputtering and surging like it does when it's running low on gas which I then just flick to reserve... the last couple of days it'll be running fine then I'll back the revs off a bit and it'll start doing it! The only thing that helped was opening the throttle right up.
Really weird, I assumed the carb would just need a clean out or something....
Only happens at motorway/highway speeds. What do you guys reckon?
$1,101,806
Gotta be some Suzuki excuse/cover up for a different problem....
Oxygen % in the air is near a constant 20.7% globally. Air density can change according to altitude or slight weather influenced barometric pressure variances.
Atmospheric pollution is only noticable to the human body because of the toxins and other nasties in the air. An internal combustion engine will not notice this...
Exactly what is the GN 250 modification you write of...Larger main jet or smaller main jet. I would suggest the mod is more to manage differing quality fuels globally then any atmospheric variations....
Okay Honda/Yamaha/Kawasaki/Ducati and other mechanics, you want to chip in?
L-Plate Rider
Hi there, thankyou for that useful information. Can you please give me some pointers as to how I can remedy this matter/get the modification done? I am in Christchurch and have tried the local Suzuki dealer who had no knowledge of this issue at all and no idea how to fix it. Thanks in advance!
Moped rider
OK got some solid info for you, sorry couldnt find the manual to get the actuall jet size. Talked to our senior technican to make sure this is correct.
For new (chinese) GN250
Change the pilot jet to the next size up.
Not available as genuine suzuki part, but aftermarket is available to order from any bike shop(mikuni i think).
If the bike is still a little hesitant, and espcially if you ride in town alot or short trips while the engine is cold - you can raise the needle 1 position. ( that is move the clip on the needle down 1 slot.)
This is what we have found works well, and customers have been satisfied with the results.
Of course if a GN didnt have this problem from new and it has developed since then, then this will not fix it. Most likely you have blocked jet or something like that.
Well i am not a scientist so i can only relay what has already been writen, and i would be interested to know about what, if any problems other dealerships have.
As you say im sure it is partly the design/manufacture of the bike which is at fault. The thing is we have trouble with a few models and we are the only country in the world that seems to have these problems. (again according to suzuki japan.
Most of the time its only very slight problem, (most people dont even notice it) a 1/2 turn on the mixture can make it idle a bit better. others need bigger pilots and higher needle settings but thats about it. the problem bikes seem to run only slightly lean at the low throttle opening, and go fine when wide open - so the starndard main jets are always fine. We usually find these things out fairly quickly because SNZ is only 1/2 km from our shop and they often work with us to sort things out.
Forum whore
Hmmm, not so sure about the quantity of oxygen at sea level in N.Z compared to the quantity of oxygen at sea level any where else in the world...I'm pretty sure it's always the same, sea level, is sea level, in my opinion.
BUT, you are correct on the solution to the problem!
However, All CARBED motorcycles come from the factorys nowdays with tiny little pilot jets. This is for emmission standards.
A new Harley Davidson, when it come into NZ has a small pilot, you must remove the one the bike comes with, and fit a larger one.
Harley's use a mikuni carb.
Well, they did 5 years ago.
If the dealer doesn't change the pilot at the P.D.I, the bike surges, and farts around at low operating speeds....
the pilot jet is too small!
If your GN has a 38 pilot jet, I suggest going to a 40, or even 42 pilot.
Take the original as a sample, go into Superior Motorcycles, and see if they have one in those sizes, as they quite often have pilot and main jets for Mikuni and Kiehen in stock.
Also, perhaps even consider "shimming" the needle on the slide 0.5 mm...... The new GN's are set up VERY VERY lean for emmisions standards all over the world, NZ has to suffer the problems caused by the E4 standards compliancy.... as that is where all bikes are now designed to comply.
L-Plate Rider
Thankyou to all those that have contributed...I finally think I've got all the info I need to sort the problem here in ChCh. I'll let you know how I get on after I get the new jet and make the required changes. Thanks again!
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