As an aside.-if i'da seen that bike I would have thrown the fuel into a container for my lawnmower Put fresh fuel in it ,Replaced the plug, check and set the valve clearances. Given the carb a good huck out and check the jetting is correct. Changed the oil/filter THEN taken it out for a good sound thrashing.
yz490,
Jun 11, 11:27am
Without reading it all--yet--but re the choke. If it's revving way too high with choke on its likely the choke jet is restricted as i think on those it's a pull out plunger choke but probably with a short needle attached to the choke plunger that controls the 'choke idle speed'. Also the choke will only work like it's designed to if the throttle is left shut--fully shut. But yes the high revving on choke & not being keen to fire from cold 'does' point to the fact that the choke jet is blocked or restricted. The jet will be in a cavity down in the bowl & will be a fixed jet so will need poking clean with something small enough but big enough to open it to size. It'll draw its fuel under that jet from a small hole heading under it from the bowl base--where if there's any dirt etc it'll go in there & sit under the jet. Been there done that many times since that type of carb first came out. even if your choke it cable operated it'll still be lifting the choke piston the same. take it back to the shop & diplomatically explain what i've suggested. I wouldn't be surprised if those are set a bit lean on the idle as well with emission laws nowdays & might benefit from another half turn out on the idle fuel screw [they're a fuel screw not an air screw like twostroke carbs] so out for rich & in for lean. Here's a link to a photo of a typical choke plunger but thought the needle would be tapered which it isn't. Ok there's a video link there & if you stop it at exactly at 2.54 minutes you can see the choke tube in the upper left corner. If i'm wrong about sucking fro a jet dow in the bowl cavity then the jet will the small hole seen in this tube & will suck direct from the bowl--but same principle.So choke plunger [call it choke piston] out & poke the small hole clean in 'that' tube give a blow with compressor [carefully] or nozzle of crc spray can against it then a bit of a blow & hope you have some luck. Guys at the shop may never have had to overcome things like this but likely someone there has if they've been around a while. Sorry for woffling on--then woffled more when found the video lol.
If its anything like the made under license briggs and stratton junk, or the many brands of heat pumps made entirely there - (or using some parts made there, pc boards, reversing valves etc), then i would definitely give it a miss, (re heat pumps, they are the main reason i have now retired, given up on the now constant warranty issues, totally over it, when i started in the trade, for quality brands, warranty issues were rare, we used to say to customers, we will only see you again, when you want another one, i would never compromise my integrity, and lie by saying that now)
docdoo,
Jun 12, 5:08pm
thisflyingkiwi, sorry for the late post but you have just taken me back over 60 years to my first ride, and still I persist, with an 1800cc Vtwin Suzuki. Once you have the bug be prepared to live with it forever. Mainly advice from the riding perspective but get a copy of 'The Biker's Bible' authored by Graham ALLARDICE. It may save your life one day. Happy riding.
kazbanz,
Jun 12, 5:37pm
The Suzuki GN's are a perfect example of quality jap product being then built down to a budget. literally EVERY component has been compromised in some way or another. Wiring is JUST enough to do the job,The cosmetic chrome is barely thick enough to stay shiny on the showroom floor. The plastic is brittle. Even down to the wall thickness of the fuel hose being JUST enough to do the job. Its a pretty long list of going beyond cost cutting.
pauldw,
Jun 12, 7:30pm
But the price is under $3k. Electric bicycles are highway robbery by comparison.
glang,
Jun 12, 8:12pm
Royal Enfield only changed from carb to EFI on their 500 singles in order to meet the European emissions standards, and by doing so could continue selling their bikes there. EFI allowed them to lean the mixture sufficiently to meet the standards and still have the bike run ok, but at the expense of some power. I converted my new EFI Royal Enfield 500 single to a Mikuni carb after it was run in, and performance was improved. Their 350 single still runs a carb, its emissions which must have meet the standard as this model doesn't use EFI.
desmodave,
Jun 12, 8:21pm
Can you not do something with the efi ecu to improve it ? Was just an example of old using new anyway .
bill1451,
Jun 12, 9:53pm
Why would you remove EFi and go back to carb, Why not take the wheels and tyres off and put wooden wheels on as well,
kestrel43,
Jun 12, 10:45pm
The type of rider that buys these old clunkers in the first place.
glang,
Jun 12, 11:53pm
bill1451 did you even read all of my post? - as I mentioned one reason was to improve the performance which it did. Other benefits . reliability - a Mikuni carb is troublefree, more to go wrong with EFI with its electronics, sensors, electric fuel pump etc. My EFI unit, fuel pump and emissions paraphernalia are now sitting in a box and the box is considerably heavier than the carb which replaced it, so weight saving was another advantage. I know EFI is normally a performance improvement but it wasn't fitted by Royal Enfield to my bike for that reason, it enabled them to lean out the mixture sufficiently so they could continue to sell the bike in Europe under stricter EEC emissions standards.
glang,
Jun 13, 12:11am
I hate EFI on motorbikes, a home mechanic can't work on it unless he's got sophisticated electronic gear - I've also got a 2007 Harley 1584cc with EFI. It idled a bit high when I bought it, but to adjust such a simple thing required booking the bike into my local Harley workshop so they could hook it into their special computer and change the idle speed parameter.
desmodave,
Jun 13, 3:24am
I like it myself 1st for me was on a 2003 Ducati supersport , ( no more dellorto carb tuning ) still hasn't let me down. I have another couple of Gen1 Rotax engine aprilias , pretty basic electronics as far as they go. An email to Gabro racing in Italy with info on any mods i have made and he will make a chip to suit . Unplug ecu , off with top cover , swap chip ( recommended to be earthed while doing so ) refit ecu , set trim pots if needed . Then off ya ride with the front end feeling somewhat lighter than before . Can no1 supply an upgraded fueling map for the system Royal enfield use ? . Now as for your Harley , what was the cause of the idle being to high ? Did something make it go out of wack or did another dealer set it like so .Could have been running different pipes before you bought it i spose A simple twist of a knob on 1 bike or a turn of a screw on another will adjust idel in seconds on my apes . Power commanders seem to be pretty standard fitment on efi Harleys . Lots of used units often listed on here . Fit new pipes and ya gunna need this this and that , and if ya buy this as well ya get free leather tassels for ya hand grips this week only . Heres a Harley question for ya , do they need a transponder to work ? . Was looking at 2018 model that had no key but would still start and run like . Was thinking it must have had a transponder hidden on the bike somewhere to allow it to run still . Or does the key simply unlock the ignition switch .
desmodave,
Jun 13, 3:28am
A lot of posts for a gn125 , 1 would normally see Harley in the title to see 40 odd posts . OP any joy with your bike after the visit to the shop ?
kiwigrl2,
Jun 14, 9:46am
So the current situation with the GN - The guy at the shop kept the bike and tested it out while cold, and agreed it was tough to start, and then his main concern was that it lost power and died when trying to take off in first, or when switching to second. He said his best guess is that it’s a blocked pilot jet (I think that what he said) so they’re going to try and fix that for me and then see if it’s any better. I think he also said something about altering the mixer screw? Basically they’ll have a go and if that doesn’t work he said it could be a bigger problem, but he doubts that as brand new bikes shouldn’t have big problems. At least the dealer up in Auckland is super apologetic and has assured me they’ll cover these costs.
yz490,
Jun 14, 10:29am
Yep above, heading in the right direction. Slide needle is probably fixed on those cv carbs otherwise a notch richer could be a good move to assist leanness on take off. GN125's can do anything lol. Not watched all of it yet.Love the music actually, depending on my mood! . https://www.youtube.com/watch?v=jou92DCfhrs
desmodave,
Jun 14, 12:38pm
Good they have it , whats the hold up with working on it . Wouldn't take long to do what they mention and see if the guess was right .
mrfxit,
Jun 14, 1:25pm
Test/ adjust/ test ok/ leave overnight again/ test/ adjust . . . . . . . Problems are generally only from overnight stone cold start. Yep thats going to take some time to be sure of the results.
desmodave,
Jun 14, 5:53pm
How long would it take drop the bowl to unscrew said jet to see if there's any crap like . Could even be water siting there not helping like . Not like there is going to be a lot to remove to get to carb is there . Never been close enough to a gn to be an expert on their fuel delivery granted . Yes i can understand testing and forums are often guessing . Interested to see if there is an exzact cause all the same
mrfxit,
Jun 14, 6:35pm
with the current reported problems, I can easily see 2 days delay, 3 to be on the safe side before giving it back. well, 2 whole days not counting delivery to the shop at night 1st time. Would be best for the last night to be parked outside as per it's normal parking situation. Of course, only the time worked on it would be charged.
desmodave,
Jun 14, 7:41pm
i only read guessing and the OP describing symptoms . Or have i missed something . Over night parts delivery left before Covind 19 did if they happen to need anything . I am interested in a positive outcome , and my guess would be it being pretty simple .
kazbanz,
Jun 15, 5:00pm
pretty simple really--The ruddy great line of other bikes already booked in ahead of the GN. Not being funny but every workshop I know is totally under the hammer with work.
kazbanz,
Jun 15, 5:05pm
Sorry mon but NAHH. Once the engines cold enough to need choke then it will show the symptoms.
mrfxit,
Jun 15, 10:57pm
True in part but those overnight cold temps do get a bit lower then normal daytime "cold temps" & part of the problem could also be overnight dampness. Been there done that as well.
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