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Re: 89 model running lean?
Posted: Sun Nov 28, 2010 12:02 am
by mick.mh2racing
trademe900 wrote:
What's the easiest way to put the vacuum hose back on? Is it to take off the fairings and try get it from underneath (still looks hard) or do i really have to take carbs off?
Cheers!
Carbs off can be tricky but not impossible. Sometimes they go back on straight away and other times you end up swearing and walking away.
Give it a go.
Re: 89 model running lean?
Posted: Sun Nov 28, 2010 12:08 am
by CMSMJ1
If it has got 110s in it, then lean is what it is...
Hows the air filter and so on?
Re: 89 model running lean?
Posted: Sun Nov 28, 2010 2:26 am
by trademe900
Hey guys,
managed to get a new vacuum hose on it without removing the carbs amazingly.
results: bike symptoms even worse with thin cloth slightly restricting air flow to airbox hole and subfilter added.
just a reminder again... bike is bog stock 89 model with 110 jets and stock exhaust.
CMSMJ1 wrote:If it has got 110s in it, then lean is what it is...
Hows the air filter and so on?
heey cmsmj1.... air filter is in ok condition i guess...stock air filter by looks. not a bright pink but not totally black and worn either. what about running it without the air filter since it runs better without a cloth restricting the hole slightly? just asking since i dont wanna blow it up if its already lean!
so did the 89 bikes really not even rev out to top cleanly out of the factory? that lean?
really appreciate the help.
Re: 89 model running lean?
Posted: Sun Nov 28, 2010 4:46 am
by Cammo
My bro had an '89 (admittedly with an aftermarket pipe on it).
It was so lean it wouldn't rev out in first.
Think about this: The standard UK models came out with 122's, pretty much the same exhaust as the Jap models. Just goes to show how lean the '89 models were.
Get some 118/120 jets in there, it won't do any harm.
Re: 89 model running lean?
Posted: Sun Nov 28, 2010 7:36 am
by trademe900
sweet I guess that's the fix. it starts awesomely, idles great (little rich actually) and pulls hard as in the mid range but once it hits 10k when you are just about to put your head on the tank and listen to that motor it starts surging and loses power. Must be main jets eh... i guess running without a filter to try is just going to be even leaner.
Now to find the quickest way to get 118 and 120 main jets to my door here in new zealand. should I go for the larger 122 UK sizes or do those bikes run a bit rich with standard exhausts? Is replacing just the end can mean I have to jet up considerably? Right at sea level here, 24 or so degrees c temperature.
/
If it was a faulty plug would that usually happen all over the rpm range and not just up high and full throttle?
Re: 89 model running lean?
Posted: Sun Nov 28, 2010 10:15 pm
by Cammo
trademe900 wrote:
Now to find the quickest way to get 118 and 120 main jets to my door here in new zealand.
Try Show & Go in Oz, quick mail order service. The part numbers for the jets you need are 99101-393-xxx (replace xxx with jet size). 118/120 will be fine with or without an aftermarket muffler.
http://www.showandgo.com.au/
trademe900 wrote:If it was a faulty plug would that usually happen all over the rpm range and not just up high and full throttle?
In my experience the plugs either work or they don't.
Definitely worth putting bigger jets in, but a check of the electrical system (output voltage etc) wouldn't go astray...

Re: 89 model running lean?
Posted: Mon Nov 29, 2010 3:36 am
by trademe900
Cammo wrote:
Definitely worth putting bigger jets in, but a check of the electrical system (output voltage etc) wouldn't go astray...

Thanks man. How would electrical system have a part in this?
Re: 89 model running lean?
Posted: Mon Nov 29, 2010 3:56 am
by Cammo
trademe900 wrote:How would electrical system have a part in this?
The nc's crap electrical system should be regarded as a culprit in any running issue until upgraded IMO!
