First time out

[Magic1971]

So since getting the m600 a number of weeks ago have changed belts, new fork seals, new plugs, brake pads, new front tyre , and purchased some davida vacuum gauges to sync carbs, oil changed new filter, so today thought I'd run round the block a few times to see how it was, synching carbs seemed to make a difference when I was in the garage as far as the backfiring and throttle response went (see other posts) however when riding at low speed/ pulling away it was back??? Also when pulling away felt how can I describe it... Somewhat lumpy/juddery almost vibration like but bit to lumpy for vibration??? Any ideas seemed ok once I was going through the gears and at some speed??? te backfiring am disappointed but think I may go for carb overhaul as this bike was stood for best part of 2an a half years some input on the juddering would be helpful , I even thought could it be chain/sprockets?? Anyway another point the davida vacuum gauges were spot on part from one thing the take off adapters are really long and on the left hand side of the bike the frame is in the way for something that length tried bending one but snapped it, at least it fit after that but hose probably wasn't as tight as it should have been have just ordered some small vacuum take off adapters online for a couple of quid so that will solve that little problem anyone in my area and wants to sync there carbs give me a shout as its one of those tools that will sit there for ages not getting used.would be grateful of any ideas on the above cheers

[470four]

Loose flywheel nut? :)

[Nickj]

Mine feels lumpy sometimes, usually too high a gear at too low a speed.. It's those big lumpy pistons, the 600's are only a teensy bit smaller.
How many miles and how old?
Things to consider would be carb float height, worn needle or main jet, air leak in the exhaust (my front seal needs doing but then I'd loose the ability to leech a little fuel into the pipes and generate the puff of blue flame and the bang, been told it makes people jump LOL) valve clearances

[Magic1971]

2000 only done 7.7k but been stood since 2009, have got a few gaskets and o rings from moto rapido gonna give the carbs a good clean with carb cleaner and compressor will have a look at jets etc when I clean it

[Magic1971]

Will have a bash at valve clearances also not something I've done before but got a manual so will give it a go

[johnboy44]

For Valve clearances Youtube is brilliant, I'd post a link but I;m a thicky

[Sirc]

you are right magic, depending how damp conditions were then carbs and diaphragm/pump could do with stripping and cleaning. Meanwhile though how did it run before you balanced and have you adjusted idle mixture screws yet? If you haven't and also haven't read up on them etc then be aware that they love to seize solid and if the screw heads get damaged as a consequence then it's even more work. Opinions vary but I think 2 and a half to 3 turns out is a good starting point.

[gary tompkins]

Did you drain the 3 year old petrol from the carbs and tank before running it?

[Magic1971]

Yes I drained the old fuel and runs a little better than it did now I've synced carbs anyway am a tad on the p****d off side tonight, got all carbs out no problem armed with my rebuild gaskets etc was going to give them a good clean, only to find the pilot screws totally siezed!!!! 2 or 3 attempts with a screwdriver soon messed up the heads, my idea was I'd have to use my screw extractor and buy some new ones, anyway to try and cut a long story short managed to break the part that the screw sits in (body of carb) so am a bit screwed, probably going to be on the look out for 2nd hand carbs, even more annoying is mine actually looked pretty clean. Anyone got spare carbs. :-( :-(:-(

[Pomp1]

If you can't find one here give a call to rosso corse on tuesday, I'm sure they'll have one.

[Magic1971]

Cheers just checked out their website may give them a call

[Magic1971]

So annoyed with myself

[gary tompkins]

The pilot screws should have rubber blanking plugs over them. Helps to keep the damp and corrosion at bay, however these are often removed and lost leading to seized screws. They are near impossible to drill out so replacement carbs is the only real option.

[Dookbob]

So annoyed with myself

You are not the first one to have this problem believe me, I have knackered quite a few of these carbs trying to free off/ extract the idle screws, including what you did with snapping off of a chunk of the carb body where the screw fits.
When I search for replacement carbs, I always ask the question before I bid, ( are the idle screws seized). If the reply comes back as " I don't no nuffink abaht that mate". Then you know that the screws are definitely seized.

[Magic1971]

That's exactley what I did on eBay guy said they were fine so bought them and they are good as been working on it today fitted a factory pro jet kit carbs cleaned new gaskets pilot screws 3 turns out all back together went to start and nothing, wasn't sure if fuel was getting through as had drained everything, sprayed a bit of stuff in air intake and it fired up then died , did this a couple of times now nothing what so ever , easy acces to 1 of the carb drain screws and there is fuel there in that one had a look at plugs 1 seemed wet gave them a quick dry still nothing, shut garage door down and will hav a look tomorrow, any ideas most welcome

[Dookbob]

It can take quite a bit of turning over to prime the float chambers with petrol after a complete drain down. My trick is with a small hypo syringe, give each float chamber drain point a squirt through a short length of rubber or plastic tube, then give it full choke and hit the button. I also do this if the bike has not been used for a while, saves a lot of wear on the starter system and avoids flattening the battery.

[Magic1971]

Cheers will check it out

[urbanfireblade]

I've had my carbs off probably nearly 20 times this year, lol. It always fires either within a second like the last time or always within 5 seconds every other time after re-fitting, this is on the first try too. Nearly full choke and a tad of throttle is what i do.

[urbanfireblade]

Its impossible to diagnose without seeing it, maybe a youtube video might help show us what its doing/not doing?
I doubt valve clearances as its low milage. Everything is connected up? Choke cable, fuel pipe??? Did u know there's a small fuel filter in the plastic brown T piece between the carbs where the fuel pipe attaches? Pull it out and see if its clogged up, they're easily cleaned unless its 'withered' like my old one was.
Pilot air screws when i searched forums/google etc everybody told me 4 turns out not 3, but tbh my 900 carbs i fitted to my 600 ran fine with the slightly larger needles and pilot screws were 3 1/4 turns out.
If it ran before you stripped it/the carbs and now it doesn't, then somethings not right on the carbs.
Drain each carb bowl to check equal quantity of fuel in each. Maybe float height is wrong?
Check sliders in carb lift up easily and there's no tears in the rubber when you remove the top of the carbs(2 screws and lift off lid).

[Magic1971]

Thanks yes ran ok before I changed carbs, the little filter I removed and blew it through with compressor so that's
Not clogged measured float heights and were both at 14mm wich is what factory pro jet kit reccomends i put the 145 main jet in and needle on 3rd notch as modified airbox an got k&n filter also will be upgrading pipes, will have another look today and report back,