TPS/Carb jetting/Cans!!

[VTRDark]

I got some cap heads with the FP kit for mine. But funny you should mention them cause earlier on I was looking through Keihin stuff on eBay and look what I found.

http://www.ebay.co.uk/itm/Keihin-Carb-F ... 53e4ffdfc6

You will need 6 of them.

(:-})

[Griff1977]

I got some cap heads with the FP kit for mine. But funny you should mention them cause earlier on I was looking through Keihin stuff on eBay and look what I found.

http://www.ebay.co.uk/itm/Keihin-Carb-F ... 53e4ffdfc6

You will need 6 of them.

(:-})

I was just about to respond before I saw your response Carl.

I too got some in my FP kit- guess where they are now.... Still in my FP kit!! Grrrrr.

[VTRDark]

I too got some in my FP kit- guess where they are now.... Still in my FP kit!! Grrrrr

doh, sorry I shouldn't laugh, but if you don't laugh you cry. Oh well, they are only screws. You can easily put them on if you want. Don't be too pissed off with your dyno trip mate, yeh you have splashed out a bit of cash, but it's not that bad. IMO it's slightly lean but it's dam close. You will probably find it will improve when the weather heats up a bit.

(:-})

[Griff1977]

I've just been trying to take advice from Leigh of Factory Pro.

Just FYI, and build up/back ground I've included my email conversation with him, he gives some interesting points & a pic:

From: Ian GMail Acc <igriffit@gmail.com>
Sent: Mar 18, 2013 11:40 AM
To: Leigh Thomas <leigh@ix.netcom.com>
Subject: Re: UK Honda VTR1000
Leigh/Gents
I have fitted your + 4 advancer and that has gone well.
Now, I am hoping for your help: I took my jet kit (see details below) to a Dyno company to fit & tune in (Weds 12 Mar). He wasn't comfortable with drilling the carbs, but to be honest wasn't comfortable with exactly what he was supposed to drill.
Could you send some more detail about the drilling of the main air jets, maybe any pics & details of what the effects should be?
Many thanks.
Ian Griffiths.

Then:

On 18 Mar 2013, at 19:16, Leigh Thomas <leigh@ix.netcom.com> wrote:
Ian, the main air jets is located in the bellmouth(where the air enters) of the carburetor. On a Keihin carb it is the jet directly inline with the needle. There is only one directly in line with the needle. Drilling the main air jet will increase top end full throttle power by 1-2 hp. If you don't want to do it, that's ok. The kit will still work ok. Just won't hit quite as hard on top.
Regards,
Leigh

Then:
From: Ian GMail Acc <igriffit@gmail.com>
Sent: Mar 18, 2013 12:25 PM
To: Leigh Thomas <leigh@ix.netcom.com>
Subject: Re: UK Honda VTR1000
Leigh.
Ok, thanks. Couple more Qs:
When it's drilled (I know there are 2 sized drills, front & rear), are the drills enlarging the current hole or making a fresh hole?
I will want to make sure there is no leftover metal from drilling; will I have to dismantle carbs to fully clean out? I can't imagine what I'm drilling through to? Float bowl?
Do you have a pic or link to a pic to show where needs to be drilled please?
Regards. Ian Griffiths.

Yes you are enlarging a hole that is already there. Yes you have to remove carbs and clean out any debris. I can't find a picture. Attached is a drawing of the MAJ location. You should remove everything(jets etc) from the carb and clean.
Leigh


I know it's a lot of text but I often find it useful to have detail in the requests. I also wanted to show how useful the FP guys are, over a quick email conversation!

I'm just planning my next carb fettling!!!

Hope you find above useful, because I know it isn't initially made obvious what the action of drilling the main air jet will do.

Griff.

[tony.mon]

Wouldn't letting more air in mean a leaner mixture top end?

So bigger jets needed to bring back the stoichiometric ratio?

[leevtr]

Ian, if your bike is rideable as is for now, may I suggest that you wait till the dyno day before getting the drill out, or spending any more cash. You may find a good setting from someone on the day, save yourself a lot of grief.

Up to you, and I'm not trying to tell you how to suck eggs, but your situation was the exact reason I suggested the day in the first place.

[Griff1977]

Wouldn't letting more air in mean a meaner mixture top end?

So bigger jets needed to bring back the stoichiometric ratio?

I agree Tony, and as I've got 178 & 172s in at the moment, with clip on top of the needles (leanest) I guess there is plenty of potential for riching it up.

Lee, I agree, and I'm not planning 'owt too soon - I haven't got much time at home in the near future but you know what it's like; always planning the next tweak! Need to sort the low end out first- #48 pilots might do it.

Thanks again Lee. Griff.

[seb421]

Wouldn't letting more air in mean a meaner mixture top end?

So bigger jets needed to bring back the stoichiometric ratio?

I agree Tony, and as I've got 178 & 172s in at the moment, with clip on top of the needles (leanest) I guess there is plenty of potential for riching it up.

Lee, I agree, and I'm not planning 'owt too soon - I haven't got much time at home in the near future but you know what it's like; always planning the next tweak! Need to sort the low end out first- #48 pilots might do it.

Thanks again Lee. Griff.

In the post mate to you today :-)

Sent from my GT-I9300 using Tapatalk 2

[Griff1977]

Wouldn't letting more air in mean a meaner mixture top end?

So bigger jets needed to bring back the stoichiometric ratio?

I agree Tony, and as I've got 178 & 172s in at the moment, with clip on top of the needles (leanest) I guess there is plenty of potential for riching it up.

Lee, I agree, and I'm not planning 'owt too soon - I haven't got much time at home in the near future but you know what it's like; always planning the next tweak! Need to sort the low end out first- #48 pilots might do it.

Thanks again Lee. Griff.

In the post mate to you today :-)

Sent from my GT-I9300 using Tapatalk 2

Cheers Seb. PM me with what I owe you. Griff.

[VTRDark]

Nice one, that's useful info, especially the bit regarding drilling right through to the carb bowl which was the bit I did not know about regarding drilling. If any drilling is to be done then make sure the diaphragm slide and needle is removed and also the float, main jet and emulsion tube from the float bowl before any drilling is commenced. I'm very tempted to give it a go on my spare carbs. And note that the drill bits are different sizes for each carb just like the main jets.

I agree with Tony by adding more air it may require larger main jets to balance out the A/F ratio but not 100% convinced. It's seems logical, more air=more fuel required to balance out the A/F ratio. But the reason I am not 100% convinced is because with the HRC kit that is designed to run with no airbox (much more air) the main jet sizes are in the 150's-160's, smaller than standard. The other clue that hints that it may require small is that in the FP CRB-H77-1.7-RK kit they don't supply a 188 main as they do with the CRB-H77-1.1-TI. Just seems to be odd to me why they leave that out.

I'm not sure how drilling the main air jets only affects top end. I would have thought it would add some top end as FP say but not just top end but all the way through the range. I may be wrong as I have no experience with drilling these carbs and how it effects the jetting side of things as to whether it requires smaller or larger mains. I would like to think it would be smaller as this would save fuel or is that just wishful thinking You never know you may discover a way if saving more fuel. Mmmm interesting.

Nice to see Factory Pro are being helpful and answering any questions. Thanks for sharing that.

And here is a pic of the Main Air Jet on our carbs.



(:-})

[seb421]

Your current settings and how it runs in here

http://www.vtr1000.org/phpBB3/viewtopic ... 71#p253171

[lloydie]

how do you set up the carbs to run a open top airbox ?
anyone know ?

[seb421]

how do you set up the carbs to run a open top airbox ?
anyone know ?

Don't know mate but watched a video recently and it was explaining why air boxes are better than just an exposed filters as they can pressurise with air flow

It was chav cars that was run on dyno they had removed the airbox and fit induction kits, it reduced power,

the best gains was from race filters used inside a closed airbox force fed with ram air


Sent from my GT-I9300 using Tapatalk 2

[lloydie]

I was thinking about just the lid being removed .

[seb421]

I was thinking about just the lid being removed .

i think it would be good if we used shorter stacks ,

modified and moved the air filter lower in the box then had more space above the filter to feed some extra air tubes

squeeze into and oval shape in from the side where the little opening is, and run them either under the headlight or in the scoops at the front

on the inside of the airbox you could fit a flap on the tubes so air could not exit them working like a one way valve

like a poor mans ram air lol

gap in tank for those than cant picture it