Carbs balancing or more?

[TheTengTheory]

Hi guys,

I just recently purchased my first bike, hornet 250 96. It's got 65k on the clock so far and as far as my mechanical knowledge goes. I believe the carbs need to either be balanced or something is wrong. At idle, it cannot sustain a constant RPM. I've set it so far to 2k idle speed but it'll pulse up and down from 1.5k to 2k. Asked a few bikes shops and one just reckons it'll need a balance and leave it at that. The other bike shop wants to pull it apart as it could be worn diaphragms etc etc. The difference in cost and time taken for both is 100 foir the balance and possibly 180+ for the full carb work.

My big question is. on a 250cc learner bike at 65k, Is it worth spending anymore than a standard balance? I don't want more power. I just want the engine mechanically sound. Beyond the idling, the bike runs well throughout it's rev range with no coughs or flat spots and a clunky gearbox. I believe the clunky seems to be standard and just takes time getting use to.

Thanks,
TheTengTheory

[SVboy]

The issue is if they complete a balance and thereis no improvement. Getting your carbs stripped,cleaned checked and worn items replaced would be more satisfactory.....but a lot dearer.

[GSF]

Hi guys,

I just recently purchased my first bike, hornet 250 96. It's got 65k on the clock so far and as far as my mechanical knowledge goes. I believe the carbs need to either be balanced or something is wrong. At idle, it cannot sustain a constant RPM. I've set it so far to 2k idle speed but it'll pulse up and down from 1.5k to 2k. Asked a few bikes shops and one just reckons it'll need a balance and leave it at that. The other bike shop wants to pull it apart as it could be worn diaphragms etc etc. The difference in cost and time taken for both is 100 foir the balance and possibly 180+ for the full carb work.

My big question is. on a 250cc learner bike at 65k, Is it worth spending anymore than a standard balance? I don't want more power. I just want the engine mechanically sound. Beyond the idling, the bike runs well throughout it's rev range with no coughs or flat spots and a clunky gearbox. I believe the clunky seems to be standard and just takes time getting use to.

Thanks,
TheTengTheory

I think the clunky gearbox is just a Honda thing. I've never owned a Honda but I've ridden a fair few km's on a VTR250 and that has a clunkalunk gearbox as standard.

It sounds like it needs a balance.
Whereabouts are you located? If you're in Auckland, get George from Motorcycle Doctors to look at your carbs. He's always done excellent work on my Bandit.

Being an old 250cc IL4, it's gonna need the carbs to be balanced every now and then just to keep it running, this is usually included as part of a regular service.
If there's bigger problems, like buggered diaphragms, worn needles/needle jets, they will just get worse and worse. The bike will get harder to start, run like a sack of shit and eventually not start at all, all the while guzzling lots of fuel and eating your money.
So you might as well get them inspected now and find out if there are any potential gremlins lurking further down the track. Otherwise you might end up like me and suddenly have to spring $500 on carb parts overnight when your beloved cycle shits the bed and won't start one day.

[TheTengTheory]

Thanks for the replies guys,

I'm from Palmy so abit of a distance to auckland :)

I've decided to get them balanced, previous owner was abit unsure on the engine service history so it'll be at least a balance. Getting them inspected as well since they're getting stripped. If there's more work to be done they'll let me know. Guys at AFC have been incredibly friendly and helpful since I first approached them. Despite having a dedicated honda dealer in town I'm leaning towards using AFC as my main service and parts shop. Nothing against city honda though.

Crossing fingers the carbs just need a balance. The bike itself runs very well so I don't think it'll be major

[Laava]

Hopefully as part of that balance they,ll pull the floatbowls off and check for fuel levels and shitty buildup etc. otherwise the balance thing may be just a best guess scenario.
With an oldish bike like this getting up in km,s, it can have any number of issues in any combination.Get them to chuck in some new plugs too while they have it.

[FJRider]

My big question is. on a 250cc learner bike at 65k, Is it worth spending anymore than a standard balance? I don't want more power. I just want the engine mechanically sound. Beyond the idling, the bike runs well throughout it's rev range with no coughs or flat spots and a clunky gearbox. I believe the clunky seems to be standard and just takes time getting use to.

Thanks,
TheTengTheory

Motorcycles are (can be) bottomless pits you throw money into. If you intend keeping the bike for quite a while .... spend the money to get it running right.

It may give more top end power ... but it will develop it easier at the lower rev range .... where you will notice more difference.

But the first (cheaper) step is clean/replace the air filter and plugs. Replace with new is the preferred option.

Also ... clean or replace (or fit) an inline fuel filter.

[ducatilover]

My first port of call would be checking for vacuum leaks.
I'd check the carb rubbers are sealing and the little rubber tips on the nipples on the intakes are not split.
Once and air leak is ruled out I'd look at doing a balance, I'd come and do it for a box of beer, but I'm up north for a wee while, so probably not too practical :no:

Could be screwed float heights and crud build up as mentioned before. Not too hard to do with some basic tools and skills

Worn/split/leaking diaphragms will be far more troublesome

[actungbaby]

Thanks for the replies guys,

I'm from Palmy so abit of a distance to auckland :)

I've decided to get them balanced, previous owner was abit unsure on the engine service history so it'll be at least a balance. Getting them inspected as well since they're getting stripped. If there's more work to be done they'll let me know. Guys at AFC have been incredibly friendly and helpful since I first approached them. Despite having a dedicated honda dealer in town I'm leaning towards using AFC as my main service and parts shop. Nothing against city honda though.

Crossing fingers the carbs just need a balance. The bike itself runs very well so I don't think it'll be major

yes the guys at afc are friendly arent they ,by look bikes he has there he knows his stuff too, yuor honda run alot smother after balanced carbs my cbx 400 did back

in the day

check out the white kawaski 300 nice

[TheTengTheory]

yes the guys at afc are friendly arent they ,by look bikes he has there he knows his stuff too, yuor honda run alot smother after balanced carbs my cbx 400 did back

in the day

check out the white kawaski 300 nice

Just got it back this morning. According to the workshop, they couldn't balance the carbs as they couldn't get fittings. So they drained it, changed the plugs. 2 hrs labour for that.

not sure if I'm completely happy with that but I don't have enough experience to really know if it was worth.

[ducatilover]

Just got it back this morning. According to the workshop, they couldn't balance the carbs as they couldn't get fittings. So they drained it, changed the plugs. 2 hrs labour for that.

not sure if I'm completely happy with that but I don't have enough experience to really know if it was worth.
Couldn't get fittings? I don't understand...
2 hours labour to drain carbs and do plugs on a Hornet 250? Fuck off. 45min, easily.

It has nipples on the intake for a vac tube (same size as a fuel tap diaphragm line) to get readings from.
If you haven't got 'em, the other way it to set the valve clearances (everyone is too bloody lazy to do this now) and then set the throttle butterflies to an even clearance (not as accurate as doing it with vacuum and it's actually easy enough to make your intake runners take vacuum port, but the Hornet has 'em as standard so that's all completely pointless typing on my behalf)

[TheTengTheory]

Couldn't get fittings? I don't understand...
2 hours labour to drain carbs and do plugs on a Hornet 250? Fuck off. 45min, easily.

It has nipples on the intake for a vac tube (same size as a fuel tap diaphragm line) to get readings from.
If you haven't got 'em, the other way it to set the valve clearances (everyone is too bloody lazy to do this now) and then set the throttle butterflies to an even clearance (not as accurate as doing it with vacuum and it's actually easy enough to make your intake runners take vacuum port, but the Hornet has 'em as standard so that's all completely pointless typing on my behalf)

Not exactly sure, the workshop seemed pretty confused with it as well... apparently the vacuum ports that plug into the carbs didn't fit. Not exactly sure myself due to my lack of knowledge. They did do a check of the carbs making sure it was all tight and nothing was loose. Might go back and ask them more about what exactly happened.

Soo, I hear you're quite the mechanic ducatil. When might you return be returning to the mighty manawatu? :devil2:

[carburator]

what a bunch of poofters...

what happened to using a bit of hose tube in the throat of the car and the other end stuck in your ear..

[Coolz]

what a bunch of poofters...

what happened to using a bit of hose tube in the throat of the car and the other end stuck in your ear..

Maybe he has tried that method before with the throttle wide open and it has sucked his brain out.

Very poor show.

[ducatilover]

Not exactly sure, the workshop seemed pretty confused with it as well... apparently the vacuum ports that plug into the carbs didn't fit. Not exactly sure myself due to my lack of knowledge. They did do a check of the carbs making sure it was all tight and nothing was loose. Might go back and ask them more about what exactly happened.

Soo, I hear you're quite the mechanic ducatil. When might you return be returning to the mighty manawatu? :devil2:
Has it improved anything?
Not sure when I'll be back ;)

[actungbaby]

Just got it back this morning. According to the workshop, they couldn't balance the carbs as they couldn't get fittings. So they drained it, changed the plugs. 2 hrs labour for that.

not sure if I'm completely happy with that but I don't have enough experience to really know if it was worth.

i guess might had a bit of mucking around trying to hook up the vacum guage hows it running know.

they whould given air cleaner a blast of air too and few other things, did they change the oil ?

In the old days gave you checklist of things they looked at chain filter etec cables

[TheTengTheory]

i guess might had a bit of mucking around trying to hook up the vacum guage hows it running know.

they whould given air cleaner a blast of air too and few other things, did they change the oil ?

In the old days gave you checklist of things they looked at chain filter etec cables

No, I only asked them to balance, check the plugs and repair my rear tyre. No checklist. I might back just to clarify. Feeling abit short changed :(

Ducatil: Changing the plugs improved somewhat but it still has a few coughs here and there at idling. Nothing major though.

According to them I should change the bike and get something newer. They say the engine is doing well for its age, most 250cc bikes have had it by 66k odo.

[ducatilover]

Ducatil: Changing the plugs improved somewhat but it still has a few coughs here and there at idling. Nothing major though.

According to them I should change the bike and get something newer. They say the engine is doing well for its age, most 250cc bikes have had it by 66k odo.
That's good that the plugs helped.

A Hornet is no way near had it by 66k, it just needs preventative maintenance, they are the most reliable 250 you can get and most will do over 100,000km with ease.

If you're interested in getting some spanners out have a look at this http://cbr250.com/forum/thread-8449.html

The last Hornet I did and all the MC19 and 22 CBRs I've balanced have had vac tube fittings on the intake, and even in the odd case that they don't they can be retro fitted easily and as I mentioned earlier you can bench balance them to a certain point (only works when the valve clearances are in spec)

I wouldn't put my trust in anyone who cannot balance a simple bunch of carbs