Thumper Club Forum
Technical => Bike Problems/Questions => Topic started by: Majik on March 31, 2009, 09:48:16 AM
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Love the new Goose, but the little bugger is becoming a nightmare to start in the mornings, and she finally failed me yesterday (a good kicking was given...).
I whipped the plug out last night, and it was quite carbonned up. Recharged the battery overnight, and checked the air filter (seemed a bit thick with blue oil, which I assume is filter oil).
Was still a bastard to start, but got there eventually. However, I'm talking over 60 seconds of turning over to get her going. This can't be right.
So... I've jumped to the conclusion it must be how the carb is set up. Free flow (read: bloody noisy) mismatched exhaust and the original (and gunked, I think) filter = bad running.
My plan is to get a free flow air filter on there to match the exhaust and then set the carb up accordingly. Which brings me to the question - how the hell do I do it? I've only ever cleaned a carb out, and the very concept of jets fills me with dread. Anyone any beginners guides, tips or any other suggestions to cure the bastard?
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Right - an update in the hope of some sage-like advice.
Firstly - the choke cable was absolutely knckered. New one on the way to me now (it was not closing the choke valve/brass thing completely). Should be here today, actually...
Second - I've put a free flow cone filter on her now, and can now get her started as long as I do two things:
1) The needle MUST be on the bottom of the five slots (i.e. it's richest). Won't start in any other position.
2) I turn her over for three-five seconds on 30-60 percent throttle, and then quickly back down to no throttle, keeping the starter button pressed and she roars into life and ticks over fine. (tickover is 1300 rpm)
Thirdly, she seems to rev fine all the way up to about 5500-6000 revs, then just loses power. Standard jet is 125. I've tried a 130, 135 and a 140 and it only seems to raise the max revs slightly. (Redline is 8000rpm)
Air/fuel screw is currently at 2 turns out - she starts anywhere between 1 turn and three turns out, but seems happiest ticking over at this. No physical way to adjust this whilst running, despite my ingenuity.
I'm hoping some carb sages are going to shed some light on this. Would the standard pilot jet be THAT effected by the changes, and how does it explain the bad starting before the filter change? I've cleaned out the carb, by the way, so I know there's no blockages going on here, and surely it would be a bugger to tick over if the pilot was dodgy?
*Bangs head against wall*
But I've learnt SO much about carbs in the past few weeks, which is a good thing...
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The needle should not impact starting, but you are then cranking it on a fairly open throttle before starting - suggesting that you are flooding the fuel from the needle to get enough in to start the thing - would suggest to me that the starting jets etc are an issue. Blocked, not big enough (fuel) too big (air) depending on which is bled on choke.
rough running - is this on the stand or under load? What sort of throttle opening?
My guesses
R
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This is all on the stand at the moment. Trying to get the starting problem and getting all the way through the revs sorted before I worry about power.
Throttle opening is anywhere above 60 percent really.
If I back out the fuel/air mix screw, should I be able to get away with putting the needle back to it's mid position start her? (this seems a much better point to diagnose)
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If it were me I would only change one thing at a time, so I would fix the choke problem and get it running correctly with the standard air box and air filter. This way you will always have a reference point you can go back to when juggling jets/settings get confusing.
It would be useful to know if the Goose has a slide carb or CV type carb, with a CV carb the throttle position is not directly related to the slide position.
When you say it doesnt rev out does it just stop revving out like it doesnt want to rev any more , or does it stutter.
Revving on the stand wont tell you much as there is no load on the engine, you need to ride it.
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Hi Steve.
CV carb (rubber diaphragm, raises and lowers with needle down the middle into main jet?).
It kind of bounces off at 6000rpm - like the fuel or air is cut.
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Agree with Steve - need to get it running right with the airbox etc before getting it running right without and revving on the stand is different to revving under load, though I would not expect it to not rev out on the stand and be OK under load.
My guess is that when it is getting to 6k it is drawing on the jet needle / needle jet combo and is getting too rich because of the choke issues.
1. Get the choke issue sorted - if it has been running on part choke because the choke has not been closing has anything been adjusted to compensate for this?
IN the mean time how about. Get the bike running and warm so choke is not needed. Set every thing back to standard - air screw, mixture screw etc etc and the needle. Air box on, all joints tight. Then start her up and see if it is different. If the adjustments to the needle are allowing it to start by drawing fuel into the pot on an open throttle, it may be flooding the pot on 3/4 throttle / higher revs.
To a certain extent the only jet that NEEDS changed when junking the airfilter would be the main jet as this is the one that meters fuel at WOT, when all that new air is rushing in. The needle may need richening off a little, but often is not bothered with. The old LEDAR kits used to be main jet only. If you are having to fiddle with the needle I would think the proble is elsewhere and you are covering one issue whilst creating another.
Does that make sense?
R
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Thanks Rog - all peachy clear. Last nights efforts:
???
Everything back to standard. New choke cable fitted. Adjusted the valves (badly - finding TDC is a bitch!). Didn't have the original airbox with me (it's at the missus' place). Got her started, but there is a hole of 2000 revs between 5500 and 7500 where it takes great patience and holding her mid throttle to get her to rise. WOT - engine dies. Don't know whether she's choking or drowning though.
Agh!!!!
Airbox to be grabbed from missus tonight and put back on - be surprised if it makes THAT much difference in the hole though, and she's STILL a swine to start.
:'(
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Look forward to update
R
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Update - Check it out! Direct from Suzuki Head Office in New Zealand via email - The standard carb specs and setup for the Goose (http://goose.majikal.co.uk/images/stories/downloads/CarbSpec.pdf) (PDFd by me to be geeky)
Customer service, or what?
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Airbox to be grabbed from missus tonight and put back on - be surprised if it makes THAT much difference in the hole though, and she's STILL a swine to start.
Ive found that just removing the airbox cover on an SRX makes it run weak. So it should make a difference. Just removing the snorkel on a my DR750 made the torque curve 'rough' on a dyno. So in my experience they do make a difference, especially to CV carbs.
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Customer service, or what?
Bloody right, Honda UK can barely remember that they imported the XBR, let alone answer any question about it.
GC
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I've been having similar problems with my Nordwest. It's been sat in the garage for a while and didn't want to start up, so after stripping and cleaning the starter motor,so it would spin fast enough, and a new plug it eventually coughed into life, although a bit on the rough side. Off to get MOT and it wouldn't pull under load and spluttered to a halt. Pushed it back to the local garage for some fresh fuel and it ran better but still as rough as a badgers ar$e. Got to the MOT and the guy who runs the place recommended bunging some STA-BIL into the tank. Gave it a try and after about 5 miles it was running a lot better. Now no problems with starting and it'll pull full throttle.
Jez
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rough as a badgers ar$e.
Excuse me.....We get a bad eniugh press as it is, wot with being accused of spreading TB, and being culled, wivout you bleedin bikers puttin it about that we have rough ar$es.....I'll have you know Mrs Brock finks I have an exceptionally nice ar$se...
Mr Brock the Badger
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I had problems with an XBR I bought last summer.It started easily,pulled well in mid-range on the road,but refused to rev.Maximum of 6500 in neutral,about 70mph flat out.Tried another CDI box,spent God-knows-how-many hours tinkering with various carb jets etc.,to no avail.I finally lifted the rocker box and found the cam was timed on the F mark,not the T........
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Thursday was a day full of grimy hands and shouting in the garage. However, a solution (of sorts) has been obtained.
After the new choke cable was put in, she was starting reasonably reguarly, but still needs some pretty long turn over to get going.
As for the revs maxing out at 5500-6000? Replacing the original airbox cured this completely. WooHoo! Of a kind... See, the whole point of this was to not only release some extra ponies, but also to get rid of the bloody ugly thing so I could take the side panels off, relocate the battery from under the seat and get a lovely looking trellis frame effect posing off the back of the engine and the space under the seat. So although she's now going fine, I'm trying to decipher why the cone filter prevent her reving out. I'm making an educated guess that it's due to the way the CV carb works and it needing some kind of "still air" or pressure to raise the diaphragm.
Help? I want rid of this bloody airbox...
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So do you still need the needle on the lowest ring and crank her on 30 - 40% open to get her to start, or is the needle back as per spec?
It may be that the flat spot with the cone filter is due to the mix being too weak on the needle? Maybe it will need the circlip raising rather than dropping - as you had to start it when the choke was to pot?
R
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Nope - I've put her back to spec now. She's starting, but irreguarly again. Driving me nuts! Someitmes she'll burst into life after 30 seconds of trying (and yes, I still need to go 30-40 percent and then chuck it back to closed throttle for her to have a chance of catching).
I've got a final theory I may test tonight with a spare battery - the higher revs is are making the spark stronger, and therefore the battery isn't in good enough nick to start her from no throttle turnover...
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Used to have a CB250 that needed 30% throttle or there abouts and lots of spinning to start - but then she had a pair of exhaust valves with splits in them so would not hold any compression... Have you got compression?
Still sounds a little like the pilot jets are causing probs and not letting enough fuel through - just guessing mind
What is she like to start when warm?
R
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If I go for a start within a minute of her being turned off, she's fine. Anything more than five minutes and chances have increased, but she's still a bitch.
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Mmmm - still sounds like a pilot jetting problem - maybe I am stuck on a single solution. Warm engine with a bit of fuel still in the tract etc will start, (ie within 1 min or so) let the fuel evaporate off - 5 mins or so - bitch to start - sounds like low throttle fueling - or a weak spark as you have thought. Any luck with the battery? - it is 12v? can you not run some jump leads from a car to see if this make a difference?
R
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DId the battery test last night - absolutely fine. Have ordered a new pilot jet for her from Allans. I'll let you know :)
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New pilot jet went in - starting is no better :( Had ordered a slightly bigger pilot alongside the standard one to be sure) no dice on the starting (although she's picking up faster through 3-6000 revs).
I'm becoming convinced that my carb is not the problem.
Could the starter not be spinning fast enough? The starter speed increases with the throttle, so could the starting sequence of 30% to no throttle be carrying starter speed through to the correct carb settings (i.e. no throttle) to start her up?
Coil problem?
I'm a luddite on electrics...
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DId the battery test last night - absolutely fine. Have ordered a new pilot jet for her from Allans. I'll let you know :)
Did you replace the battery ?. I use an old battery out of a diesel and jump leads to check if the battery is border line.
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Yep - jumped off a good diesel battery as well. All good.
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Does that mean that it started well from a jump battery or that all the starting problems remain?
Does it have a decompressor and is this working / stuck open?
R
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Sorry - unclear. Same problems. Same effect as battery on it;s own. No decomp lever - have been thinking about this - there must be an auto decomp somewhere, right? Working off a cam or something? Where would I look to see if it's broken/stuck?
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Sorry I haven't been keeping y'all updated, but the bloody thing totally died on me. I can only assume it's all related, and I'm now looking at a bike with no spark...
SO far I've:
Replaced the coil/plug
Replaced the reg/rec
Replaced the CDI (at GREAT expense...)
Gone through the loom as best as my limited knowledge will allow me to check for continuity.
Checked the sidestand / clutch / kill switches.
Nothing. Occassionally (as in once every week or so) I'll get a big fat blue spark on the first push of the button. If I keep the starter going, it'll keep sparking. As soon as I stop, the next push will produce zip, and she'll be down for ages. No rhyme or reason to when she'll give me a spark again.
For the love of God, help me...
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All at sea on this one but it sounds like something somewhere is breaking down when the lekky pixies run through it.
No idea what though and could be totally wrong - usually am
R
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I see no mention of replacing plug cap & lead .... maybe? Also, it's not unknown for spark plugs to be duff out of the box, even being sneaky little beggars and sparking OK against the head, but failing when under pressure.
HTH
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Lead - yes. Plug cap - no. Good point. (If it turns out to be this after all I've spent, I'm going to scream).
;D