Carb balance. Help?

[kiwi-on-wheels]

Hey guys, i'm looking to do a carb balance on my '88 mc17 cbr250r, so quad carb. i've not got a manometer or vacuum gauges, but i can swing a spanner with some competence.

symptoms, idles at about 2k and rough as guts, any slower it dies. with throttle pinned it goes like the clappers, definitely feels like all 4 cylinders are happy, but at part throttle it feels like its quite rough. stupid amounts of vibration, but that could very well be the age of the bike LOL

i can travel to people around auckland no worries, or if anyone wants to come to me i'm out east auckland, pm me for address

thanks!!!

[kiwi cowboy]

Hey guys, i'm looking to do a carb balance on my '88 mc17 cbr250r, so quad carb. i've not got a manometer or vacuum gauges, but i can swing a spanner with some competence.

symptoms, idles at about 2k and rough as guts, any slower it dies. with throttle pinned it goes like the clappers, definitely feels like all 4 cylinders are happy, but at part throttle it feels like its quite rough. stupid amounts of vibration, but that could very well be the age of the bike LOL

i can travel to people around auckland no worries, or if anyone wants to come to me i'm out east auckland, pm me for address

thanks!!!

Just make ya own out of tube and do 1&2 then 3&4 then 2&3 :msn-wink:

I posted pics of mine on here so should be findable.:laugh:

[F5 Dave]

Chances are the small pilot jets are clogged with some shit.

[Akzle]

hows the plugs?

[kiwi-on-wheels]

Unsure how the plugs are, got new ones to shove in, just dont have the right tools to do it atm...

Might go buy me some new tools today LOL

[Vinz0r]

Give the carbs a really good clean out first with some solvent. Remove the jets and soak them in solvent, then blow them out with compressed air.
Only balance the carbs when you've sorted every other potential issue, or you'll just have to do it again because it'll still run like shit.

[kiwi-on-wheels]

Ok so, new plugs in, carbs off, stripped, cleaned out with carb cleaner, wd40 and elbow grease, (so clean now) reassembled.

Pilot screws all reset to 1 And 5/8 turn (manual recommends between 1.5 and 1.75 turn) some were waaaaay out of whack, one was wound right in, 2 outer ones were set to 2.5 turns which is aus market spec, and one basically fell out when i touched it.

carbs synchronised on bench (have diy manometer, but need to get the vacuum nipple attachments, so ordering 4 of, and will leave them installed and capped)

Ran a new earth wire between the igniter units and the bike frame

Bikes been started and run, taking it for a ride very shortly.

Differences, it idles at 1500, previously itd die below 2500, spark is muuuuch stronger, revs happier, so much smoother lots less vibration, it actually sounds good.

Will head out for a ride shortly to see how she goes.

Next job on the list is the clutch... not looking forward to that one, but it'll be a crapload cheeper and easier than my subaru!!!

[Paul in NZ]

Well done that man...

[Vinz0r]

Great result!

[kiwi-on-wheels]

Just got home, did the kaiaua hunua loop.

Impressions, holy f**king jebus, i thought it had some pep before!!! Sooooo much smoother, just did 180kms with a 10 min brake in kaiaua, hands arent aching from the vibration!!! seems a lot happier to rev, No longer feels like it just runs out of puff at 100km/h, it just keeps on pulling

[Banditbandit]

Just got home, did the kaiaua hunua loop.

Impressions, holy f**king jebus, i thought it had some pep before!!! Sooooo much smoother, just did 180kms with a 10 min brake in kaiaua, hands arent aching from the vibration!!! seems a lot happier to rev, No longer feels like it just runs out of puff at 100km/h, it just keeps on pulling

Awesome .. but are your hands aching from the 10-minutes of braking ???

[kiwi-on-wheels]

Lol, break... english fail

[adam666]

Where did you get your vacuum nipples from?

just about to reassemble my mc17' engine (think a mc19 motor) and cant find any local source for 5mm metric threaded hosetails

Cheers
Adam

[kiwi-on-wheels]

Aahh, another Adam :-)

Still hunting for some, will try repco and supercheep this weekend, might have to order them in from the states (ebay) but jaysus its hard finding them

[nzspokes]

Model shops from memory. Give em a ring. For RC cars.

[Akzle]

hydraulink/enzed. Grease nipples.

[adam666]

Carbtune.com has them with caps.

Will check enzed in monday

Cheers