1990 900SS Small End

discussion about the 750 Sport and '89/'90 900SS, which share many mechanicals with the Paso series
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The Paua Poacher
Posts: 69
Joined: Fri Jan 24, 2014 9:00 am
model: 900 SS
year: 1990
Location: New Zealand

1990 900SS Small End

Post by The Paua Poacher »

After a year of very slow progress on parts I am almost there

Where I am stuck is who sells the small end bush/bearing (conrod to piston)

Before anybody asks why replace if not broken ... For the record most of the bearings needed replacement so I replaced all of the bearings & whilst I dont want to spend money for no reason I also want this to be a good mechanical runner i.e. I am keeping this machine long term ... so for the sake of say $40-$50 dooooollars why leave in there

The ones in there appear fine but as mentioned with bearings, seals, pistons ,etc why wouldnt I whilst a complete rebuild

Your expert advice would be appreciated on where to find would be great
Mc tool
paso grand pooh-bah
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Joined: Wed Dec 05, 2007 12:35 am
model: 906 Paso
year: 1990
Location: Newzealand

Re: 1990 900SS Small End

Post by Mc tool »

I would be surprized if anyone sells those bushes separate , probly need a whole rod . I know what your saying about the TOTAL rebuild , a good nights sleep an all that but , if there is nothing wrong with the bushes you will gain NOTHING but debt by replacing them........if you even can . Im sure a good engine reconditioner could sort that for you , maybe modify a bush off something else .
Hamish
I wish I was young again............Id be heaps smarter than last time
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higgy
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Re: 1990 900SS Small End

Post by higgy »

Most likely comes with the rod but as Mctool states any decent engine overhauler should be able to fix you up if not a bearing shop
Ducati,making mechanics out of riders since 1946
There's no problem so bad that a little fixing can't make it worse! : )
If it ain't broke keep fixin it till it is
88 750
90 906
92 907ie
The Paua Poacher
Posts: 69
Joined: Fri Jan 24, 2014 9:00 am
model: 900 SS
year: 1990
Location: New Zealand

Re: 1990 900SS Small End

Post by The Paua Poacher »

Righto

All makes sense ... apologies for the newbie question

I have only been involved in 2 strokes in years gone by ...joke about that some other time but now that I am a big boy (old) this is the machine for me... which obviously a bit different (easier) than this exercise

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Mc tool
paso grand pooh-bah
Posts: 1873
Joined: Wed Dec 05, 2007 12:35 am
model: 906 Paso
year: 1990
Location: Newzealand

Re: 1990 900SS Small End

Post by Mc tool »

The Paua Poacher wrote:I have only been involved in 2 strokes in years gone by ...joke about that some other time
Now is good for me :D
I wish I was young again............Id be heaps smarter than last time
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ducinthebay
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year: 1990
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Re: 1990 900SS Small End

Post by ducinthebay »

Top end bushes are usually pressed in, then reamed to size. Very important to ream them in the correct angle, then drill the oil holes, deburr, and add relief. All in all, not a simple task. Its not a do it yourself job, unless you have a proper machine shop in your garage. A new wrist pin will take up much of the wear anyway. Easy to find a new wrist pin, especially if you got a new set of pistons. Check the free play between a new wrist pin and the old bushing before you make the move. Changing out the top bushing just is not done too often, and finding a service to do it will be a bit of work in itself. E-bay rods from a low mileage motor will be much cheaper.

Cheers,
Phil
Duc in the Bay
1990 750 Sport x2-Rosso Blanko (900ss copy) & Nuovo Nudo (Scrambler project)
1991 907 -mostly stock
2002 ST4s - Lots of mods.
The Paua Poacher
Posts: 69
Joined: Fri Jan 24, 2014 9:00 am
model: 900 SS
year: 1990
Location: New Zealand

Re: 1990 900SS Small End

Post by The Paua Poacher »

Update

The small end measured 1000 over max (not sure why so worn as not a high mileage machine which is why I bought it - that said no one knows full history unless owned from new ...maybe didn't keep up with oil maintenance) so whilst being balanced with new piston etc small end being replaced by engineer with the expertise and the gear - cost about extra $100 Nz dollars on balancing bla bla ... Both were necessary and worth it ... That was the last bearing in the whole machine that wasn't replaced anyway

The bush is apparently pretty standard as he made the call while I was there dropping off the crank ... Will update with details of the bush when I pickup for reference
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higgy
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Re: 1990 900SS Small End

Post by higgy »

sounds like a reasonable price to me :beer: not a complicated job but very time intensive to get it proper and of course you need the proper tools :mrgreen:
Ducati,making mechanics out of riders since 1946
There's no problem so bad that a little fixing can't make it worse! : )
If it ain't broke keep fixin it till it is
88 750
90 906
92 907ie
The Paua Poacher
Posts: 69
Joined: Fri Jan 24, 2014 9:00 am
model: 900 SS
year: 1990
Location: New Zealand

Re: 1990 900SS Small End

Post by The Paua Poacher »

The small end is Nissan GA16/RB4107 19x22

Here's what they did (I made sure Staked to be sure)

REMOVE CON-RODS FROM CRANK.
REMOVE 2 X LITTLE END BUSHES FROM CON-RODS. MEASURE NEW BUSHES,
FREEZE FIT NEW BUSHES TO CON-RODS, DRILL OIL HOLES, HONE BUSHES
TO SUIT GUDGEON PINS. CLEAN, ALIGN CON-RODS, FIT BIG END
BEARINGS TO CON-RODS, CHECK CLEARANCE IN SPEC. & REMOVE BEARINGS.
BALANCE 2 X PISTONS, 2 X CON-RODS, SET UP BOB WEIGHTS, BALANCE
CRANK 52%, POLISH CRANK.
REMOVE OIL PLUGS FROM CRANK, ACID TANK CLEAN CRANK.
FINAL CLEAN CRANK, FIT OIL PLUGS, LOCKTITE STAKE OIL PLUGS, FIT
RODS TO CRANK.
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higgy
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Re: 1990 900SS Small End

Post by higgy »

:thumbup: :beer: :beer: :beer:

G you paying attention, that nissan info belongs in the FAQ :beer:
Ducati,making mechanics out of riders since 1946
There's no problem so bad that a little fixing can't make it worse! : )
If it ain't broke keep fixin it till it is
88 750
90 906
92 907ie
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paso750
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Re: 1990 900SS Small End

Post by paso750 »

I am and everyone is free to post relevant infos in the FAQs. ;)
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paso750
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Re: 1990 900SS Small End

Post by paso750 »

I put this in the FAQs now and then checked the '90 900SS parts catalogue. Other than the 750s parts catalogue the 900SS one lists the small end bush as #71110071A. I then googled the part number and found that it`s actually the same on many newer Ducs and no problem finding it.
http://www.2wheelpros.com/oem-parts/duc ... -part.html

2001 Ducati MH900E
2001 Ducati Monster I.E 900
2001 Ducati SportTouring ST2
2001 Ducati SuperSport Sport 900
2002 Ducati MH900E
2002 Ducati Monster IE 900
2002 Ducati SuperSport Sport 900
2002 Ducati SuperSport Standard 900
2003 Ducati Monster S 1000
2003 Ducati Multistrada DS 1000
2003 Ducati SportTouring ABS ST2
2003 Ducati SportTouring Standard ST2
2003 Ducati SuperSport SS 1000
2004 Ducati Monster 1000
2004 Ducati Multistrada DS 1000
2004 Ducati SuperSport 1000
2005 Ducati Monster Dark 1000
2005 Ducati Monster Dark 2 Dis 1000
2005 Ducati Monster Standard 1000
2005 Ducati Multistrada DS 1000
2005 Ducati Multistrada SDS 1000
2005 Ducati SuperSport DS 1000
2006 Ducati Monster 1000 S2R
2006 Ducati Multistrada DS 1000
2006 Ducati Multistrada SDS 1000
2006 Ducati SportClassic LE Paul Smart 1000
2006 Ducati SportClassic Standard 1000
2006 Ducati SuperSport DS 1000
2007 Ducati Monster 1000 S2R
2007 Ducati Multistrada S 1100
2007 Ducati Multistrada Standard 1100
2007 Ducati SportClassic Biposto 1000
2007 Ducati SportClassic GT 1000
2007 Ducati SportClassic S 1000
2008 Ducati Hypermotard S 1100
2008 Ducati Hypermotard Standard 1100
2008 Ducati Monster 1000 S2R
2008 Ducati Multistrada S 1100
2008 Ducati Multistrada Standard 1100
2008 Ducati SportClassic Biposto 1000
2008 Ducati SportClassic GT 1000
2008 Ducati SportClassic S 1000
2009 Ducati Hypermotard S 1100
2009 Ducati Hypermotard Standard 1100
2009 Ducati Monster S 1100
2009 Ducati Monster Standard 1100
2009 Ducati SportClassic GT 1000
2009 Ducati SportClassic GT Touring 1000
2009 Ducati SportClassic S 1000
2010 Ducati Monster S 1100
2010 Ducati SportClassic GT 1000
2011 Ducati Hypermotard EVO 1100
2011 Ducati Hypermotard EVOSP 1100

It's the also same on the 906, 907ie, 900SS, 900SSie, 900 Monster, 900ie Monster, Cagiva Elefant 900 etc etc
All 4 valve engines have different bushes as seem to have the smaller engines.
The gudgeon pin of the 900SS (19mm diameter) & the 750S have different part numbers so the small end bushes might be different.
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