Mikuni experts, your answers please...

discussions specific to the 906 Paso
User avatar
paso750
paso grand pooh-bah
Posts: 5558
Joined: Sun Jul 18, 2004 12:00 am
model: 750 Paso
year: 1987
Location: southern Germany

Re: Mikuni experts, your answers please...

Post by paso750 »

do the cables have a bent plastic tube on its end ? Some have and if they do they will only fit with certain throttle grips. I guess you could take your throttle cable to a bike shop and just see what they have.
lane1feathers
Posts: 258
Joined: Thu Sep 20, 2012 11:48 am
model: 906 Paso
year: 1989
Location: Perth, West. Australia

Re: Mikuni experts, your answers please...

Post by lane1feathers »

I'll get some cables made up from the local bike shop, no drama.
Got it goin today.
http://youtu.be/iI80jPLB97U
Lane
89 Dark Blue 906 Paso
Ducati Paso, It's an 'understanding'....
lane1feathers
Posts: 258
Joined: Thu Sep 20, 2012 11:48 am
model: 906 Paso
year: 1989
Location: Perth, West. Australia

Re: Mikuni experts, your answers please...

Post by lane1feathers »

Well, getting one made up from the local bike shop WAS a drama as they don't make cables anymore. :oops: there is a place in Welshpool that does make them up...but it'll take two days and cost $100 for the two cables. Then I realized...the carbs came from a TRX850... which shares the same engine with the TDM850...same carbs, longer cables :thumbup: So I rang the wreckers, they had a pair and a twist grip from same bike for $50. Sweeeet. They are 230mm longer than the 900SS ones I have that are too short so should be long enough. I'll nip over there in the morning and pick em up.
Lane
89 Dark Blue 906 Paso
Ducati Paso, It's an 'understanding'....
lane1feathers
Posts: 258
Joined: Thu Sep 20, 2012 11:48 am
model: 906 Paso
year: 1989
Location: Perth, West. Australia

Re: Mikuni experts, your answers please...

Post by lane1feathers »

Mikuni conversion complete. :thumbup: :beer: :beer: :beer: OMFG what a transformation. I haven't got the pod filters on it yet and it was dark when I finished so didn't want to go too far with no indicators but the little joy ride I just went on made all the dramas worth it. There is instant throttle response with no flat spot whatsoever. I can decelerate on approach to a roundabout with no stumble, just smooth engine braking, then I can potter around the roundabout (small, single laned) in 2nd @ 2000 rpm, still no stumbling, then I can accelerate out of the roundabout with no flat spot, just smooth acceleration. Then when I stop and go again WOT it just goes from 1200 to 8000 instantly, no fuss, no cough, no flat spot just a big kick up the arse with the front wheel lifting off the road. :lol: :lol: :lol: :lol: :lol: Goes like a 900SS.

So, I thoroughly recommend doing the mikuni conversion...BUT, if you decide to do the same I would advise using a carb from a 900ss not a Yamaha (TRX/TDM) as the cables come in from the back which creates its own dramas. I managed to get around them by using longer cables but its just so much easier to go with Ducati from the onset.

It pays to strip the them down and kit them (or just get one from Gerhard :thumbup: ) and clean them and check everything is where it should be. First start up saw the bike running on one cyl. at idle and then the other kicking in when throttle opened. I thought this was just a balancing issue but it turned out there were bits missing! (A small jet buried deep in a foxhole next to the main jet was missing, is this the idle jet? or is that the larger jet with a screw slot in top in the same group of three? Dunno, doesn't matter) I only knew there was something missing when I looked in the other one! Luckily my mikuni came with a spare (thanks Dan)

I had stripped the head of the mixture screw and couldn't get to it to re groove, so I drilled 3 very small holes in a row in the head so I could get a screwdriver to turn it. Got it out, ditched it and replaced with a good one from the spare carb. I replaced the little o rings as well, as the DJ kit came with a bunch of little o rings :thumbup: I wound both out 3 and a half turns.

Thinking I had covered everything, I put it all together on the bike including tank and seat and went for 2nd start up. She burst into life and all was looking good for a test ride. As I was wheeling it out of the garage I noticed fuel pissing out and onto the floor :mad: it was coming out of the overflow on both carbs. I'm still running the electric fuel pump so I removed the restrictor jet in the return line and now no more leak :thumbup: I will be using the vacuum pump I got from Gerhard (thanks again G.) but the electric one works so for now it stays.

I still have so much more to do but now it's goin so good I just want to put the fairings back on and ride it...so I think I will :lol: We still have some riding weather here in West Oz before the wet stuff sets in so I'm gonna go make hay........
Lane
89 Dark Blue 906 Paso
Ducati Paso, It's an 'understanding'....
User avatar
907pasonut
paso grand pooh-bah
Posts: 604
Joined: Tue Jul 20, 2010 9:27 am
model: 907 I.E.
year: 1992
Location: Melbourne Australia

Re: Mikuni experts, your answers please...

Post by 907pasonut »

sounds like you have the carburation working well
post another vid when its on the road :thumbup:
Cheers Claude.

...long live the square framed duc!

'92 907...numero 2046
'92 851...in progress
User avatar
paso750
paso grand pooh-bah
Posts: 5558
Joined: Sun Jul 18, 2004 12:00 am
model: 750 Paso
year: 1987
Location: southern Germany

Re: Mikuni experts, your answers please...

Post by paso750 »

That doesn`t sound to bad, but put on those filters and get the carbs adjusted properly. :)
It´s interesting that you now have a mixture of a TRX/TDM jetting and a Dynojet kit of a 900SS. :huh: :lol:
... but it turned out there were bits missing!
That`s why I said you always need to check all jets and note their sizes and also check if all o rings and washers are at their place. You never know where such a carb came from specially if you get one on ebay. Previous owners may have messed with it, or put a Mikuni of a 750 on a 900 w/o replacing all different jets etc. Specially if you have to rejet due to mounting it on a different bike, having open filters or exhaust you need to know the current jetting as a starting point.

7 is the starter, 6 the main and 8 the idle jet.
When you replaced the o ring on the adjuster screw did you check if there`s still the washer between it and the spring (#12) ?
As the adjuster screws are on the front I recommend to find two plastic caps to fit over them. Of course you can also find a rubber tube that fits over it, heat up one end until it starts to melt and then squash it with flat pliers. This should protect them from humidity and dirt and from seizing.

G.
Attachments
Mikuni.jpg
Mikuni.jpg (55.03 KiB) Viewed 9719 times
DSCF7393.JPG
DSCF7393.JPG (37.96 KiB) Viewed 9719 times
DSCF7392.JPG
DSCF7392.JPG (40.84 KiB) Viewed 9719 times
User avatar
Fraser
Posts: 334
Joined: Tue Jan 17, 2006 12:00 am
model: 750 Paso
year: 1986
Location: Lower Hutt, New Zealand

Re: Mikuni experts, your answers please...

Post by Fraser »

Lane,

Welcome to the world where the Paso will perform as designed. Your Mikuni setup transforms the performance. Has the same experience with my P750.

Cheers,
Fraser.
750 Paso
1980 Moto Morini 500 Sport
lane1feathers
Posts: 258
Joined: Thu Sep 20, 2012 11:48 am
model: 906 Paso
year: 1989
Location: Perth, West. Australia

Re: Mikuni experts, your answers please...

Post by lane1feathers »

:cool: thanks Fraser :thumbup: she's certainly a different machine. I'm glad they put mikunis on the SS and the monster of the 90's, or they wouldn't have sold many :mrgreen:

Gerhard, thanks for your help in this operation (he PM'd me a lot) you are very unselfish with your time and your wisdom :thumbup:
It was No. 8, the idle jet that was missing. One cyl was flooding then coming to life when throttle open. Probably why there was so much smoke too, unburnt fuel.
Both inlet tubes had two holes each. Three were plugged and one has the vacuum pipe goin to digiplex.
In the mixture screw combination it went; main screw, spring, washer then rubber oring to seal :thumbup:
Lane
89 Dark Blue 906 Paso
Ducati Paso, It's an 'understanding'....
Andrew2
paso grand pooh-bah
Posts: 574
Joined: Thu Oct 27, 2011 7:47 am
model: 750 Sport
year: 1988
Location: Wollongong,Australia

Re: Mikuni experts, your answers please...

Post by Andrew2 »

G'day Lane,
that's a fantastic job.When I had my 750 Paso I put 40mm Delortos on and like you I was thrilled with the difference it made.Nice video too.Seems you dye your hair the same colour as me :lol: :lol: :lol:

Cheers
Andrew
lane1feathers
Posts: 258
Joined: Thu Sep 20, 2012 11:48 am
model: 906 Paso
year: 1989
Location: Perth, West. Australia

Re: Mikuni experts, your answers please...

Post by lane1feathers »

Nice video too.Seems you dye your hair the same colour as me

Ha ha, yeah it comes in a bottle called "Three teenagers" :mrgreen: :mrgreen: :mrgreen:
Lane
89 Dark Blue 906 Paso
Ducati Paso, It's an 'understanding'....
Harry
Posts: 90
Joined: Mon Aug 30, 2010 3:15 am
model: 906 Paso
year: 1989
Location: Denmark, Western Australia

Re: Mikuni experts, your answers please...

Post by Harry »

Love the " stop filming thats a rap" hand signal at theend of the youtube clip as well mate very professional haha. Good to see it worked out well there lane1 i have my golden tyres fitted now and next step is belt replacement and the same carb conversion , cant wait :lol:
lane1feathers
Posts: 258
Joined: Thu Sep 20, 2012 11:48 am
model: 906 Paso
year: 1989
Location: Perth, West. Australia

Re: Mikuni experts, your answers please...

Post by lane1feathers »

Mate, you'll love it :thumbup:
Lane
89 Dark Blue 906 Paso
Ducati Paso, It's an 'understanding'....
Andrew2
paso grand pooh-bah
Posts: 574
Joined: Thu Oct 27, 2011 7:47 am
model: 750 Sport
year: 1988
Location: Wollongong,Australia

Re: Mikuni experts, your answers please...

Post by Andrew2 »

lane1feathers wrote:Nice video too.Seems you dye your hair the same colour as me

Ha ha, yeah it comes in a bottle called "Three teenagers" :mrgreen: :mrgreen: :mrgreen:
I see you're using the high potency formula :huh: .I'm down to the "one has left home and ones being a brat formula" :lol: :lol:
lane1feathers
Posts: 258
Joined: Thu Sep 20, 2012 11:48 am
model: 906 Paso
year: 1989
Location: Perth, West. Australia

Re: Mikuni experts, your answers please...

Post by lane1feathers »

Half strength :D you'll probably start gettin your colour back soon :lol: :lol: :lol: :lol: :lol:
Lane
89 Dark Blue 906 Paso
Ducati Paso, It's an 'understanding'....
Andrew2
paso grand pooh-bah
Posts: 574
Joined: Thu Oct 27, 2011 7:47 am
model: 750 Sport
year: 1988
Location: Wollongong,Australia

Re: Mikuni experts, your answers please...

Post by Andrew2 »

lane1feathers wrote:Half strength :D you'll probably start gettin your colour back soon :lol: :lol: :lol: :lol: :lol:
:lol: :lol: :lol: :lol:
Post Reply