Flat spot at 1/4 to 1/2 throttle?

[nzspokes]

This is not just a matter of servicing. The last time I had this done it cost $800 by the time the labour was added on.


Why would a VFR cost more to service? They're both four cylinder engines?
Even if it does, I doubt it sould be $800. For me that amounts to over $50 a week.

Buy a manual and do it yourself. Its a carburetor not rocket science. I did a jet swap in 35 mins this morning. I reckon I could do the needles and seats in 3 beers or an hour. I did needles and seats on my Bandit, from memory parts were $70.

VFR is V-tec so more to check in a proper service. And more to pull off to get there.

[swbarnett]

If I remember rightly certainly, the older katana's were time consuming to get at stuff.

This is ceratinly what I was told was true for mine.

The VFR will likely cost more to service as it is a V. So two covers to take off etc etc.
think they have Vtech now too, as well don't they?

VFR is V-tec so more to check in a proper service. And more to pull off to get there.

I see what you mean. Certainly if I can get mine fixed properly I'd rather keep it.

Buy a manual and do it yourself. Its a carburetor not rocket science. I did a jet swap in 35 mins this morning. I reckon I could do the needles and seats in 3 beers or an hour. I did needles and seats on my Bandit, from memory parts were $70.

Honestly, carbs are just one step more than I'm prepared to tackle.


I'll have a word to the mechanic that did the job last time and see what they say given what you guys have told me. Honestly, it doesn't sound like they did the job right. We'll see what they say.

[unstuck]

This is ceratinly what I was told was true for mine.



I see what you mean. Certainly if I can get mine fixed properly I'd rather keep it.


Honestly, carbs are just one step more than I'm prepared to tackle.


I'll have a word to the mechanic that did the job last time and see what they say given what you guys have told me. Honestly, it doesn't sound like they did the job right. We'll see what they say.

See if you can find an old bike carb somewhere, and have a fiddle around with it a little. They are mostly not as scary as you may think. You can do eeeet.

[husaberg]

This is ceratinly what I was told was true for mine.



I see what you mean. Certainly if I can get mine fixed properly I'd rather keep it.


Honestly, carbs are just one step more than I'm prepared to tackle.


I'll have a word to the mechanic that did the job last time and see what they say given what you guys have told me. Honestly, it doesn't sound like they did the job right. We'll see what they say.

I think they did it properly because it worked yes, just the parts are shite quality now not their fault.
Don't be scared of carbs There is f-all to f-up. they are pretty simple if you can do an oil and filter you can do them.

[nzspokes]

This is ceratinly what I was told was true for mine.



I see what you mean. Certainly if I can get mine fixed properly I'd rather keep it.


Honestly, carbs are just one step more than I'm prepared to tackle.


I'll have a word to the mechanic that did the job last time and see what they say given what you guys have told me. Honestly, it doesn't sound like they did the job right. We'll see what they say.

Well first yes I would talk to whoever did the job and ask why it failed so quickly.

If that goes nowhere ask on KB if somebody local can give you a hand to do the carbs. Pull them out yourself so whoever comes round just has to replace the parts. Easy job with the carbs off. Then give them beer.

Everybody wins.

[spanner spinner]

A furhter update - about 10,000k later and the problem has returned. Any more suggestions?

Are the carb slides chattering in the carb bodies? I would not expect the carb slides to be worn at this mileage but not impossible, if the slides are worn and chattering they put side load on the needles and cause them to wear vey rapidly as the needle is trying to centre the full load of the slide. this is easy to see as wear marks on the engine side of slides. thinking about it I have just had to replace slides on a triumph Bonneville a couple of months back that only had 30,000km on it due to slide wear and these use a similar carb slide design, worth checking. Also are you using a K&N filter? These can cause this type of carb to wear very rapidly. (bigger holes equal more air and power but also more dust getting through) What you need to check is part 11 on the following link http://www.partzilla.com/parts/searc...TOR/parts.html easy to do just lift one of the outer carb tops and lift the slide out there should be NO!!!!! wear marks on the face of the slide and wear is to much.

[Vinz0r]

I had the same problem on a Bandit and fixed it with the factory-pro nickel plated emulsion tubes. Didn't want to bother with something that was going to wear in another 20,000 kms. As said above, slide chatter wears them very fast, which could be what has happened to you.
Most of the cost of having a dealer look at carbs is labour, they're not hard to work on so get out your tools and have a crack at it. New tubes and needles shouldn't cost much more than $100, which is a shit load cheaper than what your mechanic charged you.

[swbarnett]

Further update:

Talked to mechanic. They suggested new plugs and air filter as they're not the one that services it. I swapped those out and it's a lot better. I can get decent acceleration out of it now. I can get it to red line like it used to.

It sill has a problem in the same throttle area but now it's much reduced. Once the bike is fully warm it's only noticeable as a slight softening. If I sit in the problem area and add a little choke the problem goes away. Also, it's more noticeable when the engine is cold. If I understand correctly the fact that the addition of choke improves it means it's running lean, yes?

[Vinz0r]

Further update:

Talked to mechanic. They suggested new plugs and air filter as they're not the one that services it. I swapped those out and it's a lot better. I can get decent acceleration out of it now. I can get it to red line like it used to.

It sill has a problem in the same throttle area but now it's much reduced. Once the bike is fully warm it's only noticeable as a slight softening. If I sit in the problem area and add a little choke the problem goes away. Also, it's more noticeable when the engine is cold. If I understand correctly the fact that the addition of choke improves it means it's running lean, yes?

Yep sounds like it's a bit lean through that range, is it at around 4 - 6k rpm? Might need to shim your needles, there could be a flat spot coming off the pilots onto the mains as the needle lifts. This is good as it means your new emulsion tubes are probably ok! It runs rich when they're worn.