Finally started with the rebuild

Harigeharry · Post by **Harigeharry** » Sat May 27, 2006 1:11 pm

Two years ago Gerhard gave me a shopping list for Ebay. To change the carburettor.
I bought a:
- 900 monster carburettor set (Mikuni)
- 900 SS air intakes
- 750 needles
- 750 main jet
Last two of Dynojet 1 research.

1 Get rid of the old Weber

Don't mind the background

Adjusting the valve play.

Fitting the 900 ss inlets

Fitting the Mikuni carburettor

Next time I will have more detailed photos of the settings!

We also did new wheel bearing in the frontwheel.
Trying to get the right front disk on line (no shutter)
I bought two new front disks, but they seem to be two new rear disks :thumbdown:

Setting the carburetttor up. Screwing the air needles al the way down and then up 7 HALF turns (so 3,5 full turns).

Starting right away

We will finisch the job over a week of 2.

Nice, all I need now are K&N filters for the Mikunis.
Does anyone know which filters to order???

Thanks in advance and hope you enjoy the pictures

Harry

Finnpaso · Post by **Finnpaso** » Tue May 30, 2006 5:58 pm

I enjoy very much Your fotos, especially that first one, where is something VERY CUTE in background in wall...

Thanks for that!

fasterdammit · Post by **fasterdammit** » Tue May 30, 2006 5:59 pm

Harry - looking good! I see you're not the only one getting greasy in there, too - excellent!

Thanks for taking pics and keeping us posted; I've been trying to decide what to do with my Paso re: Weber vs. Mikuni. At the moment, I'm aiming for Jon Fiore's Weber work-up, but I'm not ruling out a pair of Mikunis either. Just curious - what was the price tag associated with your new carbs, and did you in fact get them from ebay? What was the model number on that Mikuni, too?

Thanks,
Jake

Post by **paso750** » Tue May 30, 2006 7:31 pm

Jake,

get whatever Mikunis are offered. If they are from a Ducati they`re all the same. Only difference is the jetting and some may come with different fuel chamber covers (for carb heater).
If I remember correctly the TDM850 Yamaha also uses the identical carb. The prices differ very much. Some are sold for about nothing. Inlet manifolds may be more expensive and harder to find but I think they aren`t so expensive even if ordered from your Duc dealer.
If you have a 750 you should go for the 750SS/Monster inlet manifolds. Not that it makes a difference (inlet diameter etc is the same), but the 900SS/Monster inlet manifolds have a minimally different angle. So when mounted on a 750 engine the carb is minimally twisted. You may not even notice and and in fact it doesn`t matter at all if you use sport filters, but if you think of modyfing your airbox you may consider this as it will make the rest of the work slightely easier.

Gerhard

Harigeharry · Post by **Harigeharry** » Tue May 30, 2006 8:02 pm

Jake,
For superb advice You better read what the Paso master Gerhard wrote. With his advice and Ebay links I bought my stuff for a very low price.
Succes,

Harry

Post by **paso750** » Tue May 30, 2006 8:04 pm

Harry,

should I say I don`t even have that carb mounted anymore as I have another project ongoing ...

Gerhard

ps: did you use the Paso throttle grip or did you get a newer one from SS/Monster, just for curiosity

Harigeharry · Post by **Harigeharry** » Wed May 31, 2006 12:22 pm

I used the Monster grip.

As you can see in the first from last picture. If you look closely you seen the two throtlle wirers and their connections

Gerhard, what to do with the airbox. Make one like you did?
Use a K&N standard box or just the K&N Filters.
See Ya

Post by **paso750** » Wed May 31, 2006 1:34 pm

info / questions:

as the carb is higher than the Weber the airbox will become smaller and more restrictive so I`d say a K&N filter is a must if you take the airbox solution. (although I never really suffered performance loss)
Can you work with glassfibre ?

Regarding the open filter solution. How bad are noise level controls in NL and how fast do you drive ? Bauke also used sport filters with his Keihins + other mods and he really had top speed problems. The issue was probably that the carb stands upright while the air comes from the front. At high speeds wind will become so high you may have an underpressure at the carb inlet and the bike will run rich.
So my suggestion would be to make a sort of shield around them just to cover the filters rear side and maybe a little bit of the sides. I`d say this shield should not have more than 3-4cm distance to the filters. Of course that`s just my theory.

I know though that some kind of shield was available from some sport filter manufacturer. I`ve seen something like this once.

Gerhard

PS you`ve got mail

Duc750 · Post by **Duc750** » Wed May 31, 2006 3:18 pm

Open filters are a lot louder when you ride the bike (could definitely hear them more than my Conti 2:1 system) so noise control could well be an issue if the noise test is done off idle. At idle there is not that much difference between sport filters and a modified airbox.

Thinking about it my bike used to run rich at high speeds ( you could actually smell the carb over fuelling

)

but to be honest the performance was not noticeably worse (my 750 had a few compression issues as well so I suspect these masked any other problems!)

Post by **paso750** » Wed May 31, 2006 4:10 pm

but to be honest the performance was not noticeably worse (my 750 had a few compression issues as well so I suspect these masked any other problems!)

yep, but with the right setup it should`ve been better and not the same or unnoticeably worse. Thanks for the "fuel smelling" info btw. that confirms my theory a bit

Duc750 · Post by **Duc750** » Wed May 31, 2006 8:25 pm

It was certainly smoother and more responsive at low revs than the weber which is where I tneded to use the bike most of the time.

Regarding the fuel smell I only really worked out what was missing when tucked in on the 907 last week 200 KPH and no petrol smell!

I hadn't really thought that much about it until our conversation !

Harigeharry · Post by **Harigeharry** » Wed May 31, 2006 8:37 pm

Someone on the list is asking for a standard Paso Airboxfilter.
He said on rainy conditions his K&N filterbox wasn't good enough.

Might be water in the carburettor. Didn't you have simmilar problems?

Harigeharry · Post by **Harigeharry** » Wed May 31, 2006 8:54 pm

Here, this is what I mean. The difference might be the carburettor
itself.

Quote:<
Hi guys,

My PASO is actually working with the weber carb.. But it is fitted
with a universal K&N filter box which is ok, when the weather is dry,
but in Denmark the weather can at times be very unstable. So I would
like to have me the original filter box. Does any body, in preferably
Europe, have a filter box, lying around which they do not have any use
for?

PASO 750, 1990
Klaus
Denmark
> end quote.

Post by **paso750** » Wed May 31, 2006 9:03 pm

I`m not sure about what Klaus is referring to with "K&N boks".
There may be problems with open sport filters when driving in rain. Andy, a 907ie rider who came by some days ago reported about problems starting the bike after driving in the rain. He has a cut open airbox lid. (important here is to know is that 750/906 and 907ie airbox are totally different. While on 750/906 the filter element stands behind the carb, on a 907ie it`s on top leaning forward like ie on a Supersport).
If you have a 750/906 with an airbox you won`t have this problem in rain.

G..

Duc750 · Post by **Duc750** » Wed May 31, 2006 9:27 pm

To be honest K&N filters are dread full when they get wet. They have a tendency to get thjefilter medium sucked into the engine when it gets wet and soggy (seen theis happen a couple of times on V8 Range Rovers being used competitively in the UK
Foam filters like Ram Air or Piper cross are a much better bet for wet weather running.
On my 750 there was no problem with running in the wet but the filters would get wet when parked. I just used to shove a plastic carrier bag in the general area if it was parked in the rain and that seemed to cure it (Mine has cheap K&N cotton wool filter copies)

I think what Klaus means is the "trimmed lid" like my 907 has or maybe even completly cut open. This is common for some tuners to do to the 900ss airbox just leaving the frame to hold the filter in.

That definitely causies problems with wet running on nearly every bike that has it done as water can condense under the tanks and then drop down onto the filter saturating it.