(lack of) cold starting device 1989 851 Strada

Fulvia-hf

I have a 1989 Strada which I have have rejuvenated after purchase without having tried it before.
One thing I noticed when I started her up the other day was that there seems to be no cold starting enrichment present of some sort. I have to yank the throttle GP warming-up style to get her to the temperature she needs to hold a stable idle. I have heard from someone that a 916 throttle grip has some kind of crude choke mechanism build in allowing the throttle to be slightly open during warm-up. Is this true and is this 916 throttle an easy swap with my 851 Throttle?
there might be better solutions altogether.
William

rxs51

Yes it is possible to use a 916 type throttle on the 851. This has a cam mechanism built in so that pressing a small button holds the throttle slightly open during warm up but as soon as the throttle is opened it releases again. I did this mod on my 851 ages ago and seem to remember all I had to do was change one of the nipples on the end of the cable to suit one end of the linkage - not too difficult if you can use a soldering iron.

brad black

from memory the 851 cable adjuster fits inside the 916 throttle housing hole, so i just left it at that and adjusted the freeplay at the throttle body end.

Mr.R

I'm 99% sure that when I carried out this throttle mod' I had to also use a 916 cable.

Steve R

marvin

You have to adjust the throttle so there is no slackin the cable or it doesn't work.

Davo

Tuning

Hi Guys, I just wonder if it's in the tuning or set up of the injection system coupled to the TPS.
For some reason when I start mine (and I'm definitely not trying to brag here) she goes straight into an idle that has a rythmic thumping sound mixed in with it. I don't tempt fate by trying blip the throttle to quick. I do have to be a little careful when pulling out the driveway with the throttle, but it's normally okay.
89' 851 also.
Just saying.

brad black

some are. i remember doing clearances and tune on an early one years ago and it would idle from cold just fine after that.

mine won't. even with the heavy closing springs and a shitload of playing with it.

Fulvia-hf

Thanks guys for all responses. I think I will go the 916 throttle grip route.
I will search for the grip and the cable.

Cheers,
william

Mr.R

Fulvia-hf wroteThanks guys for all responses. I think I will go the 916 throttle grip route. I will search for the grip and the cable. Cheers, william

I've never regretted fitting my 851 with this mod', it's worked perfectly ever since.
The cable should be available from any Ducati dealer and most probably the complete throttle assembly.

Steve R

Fulvia-hf

Just installed the 916 throttle grip.
It was a fairly easy job. I made a hybrid cable of the 916 adjuster at the throttle end and the 851 adjuster at the butterfly end.
To do this I had to carefully grind off the lower cable end so I could remove the inner cable and change out the adjusters. Reinstall the inner cable and solder a new cable end back on. for this I used a universal screw type cable end which I modified a bit so I cold solder it instead of using the screw.
Works a threat! As the 31 year old throttle rubber was reluctant to start a second life around the 916 grip I sourced a set of new OEM early 851 throttle grip rubbers. they will arrive the coming week.

Yet to be tested but the little button does its work in preventing the throttle handle to return fully.

Thanks for the tips guys!

patrick

Mine (90) iddles perfectly at cold, finally rarely use the throotle fix button, or only to help the battery charging process a little bit.
S4r fuel ramp (with airbleed screws)
Heavy springs
Arround 108/108 timing specs
Fine valves play setting, especially the closing one (the nearest to 0,05)
Ignition and iddle fuel mappings
Trimmer screw adjusting 3- 4% Co
Low fuel map area much more leaner (between 2000 and 4500 rev and 0 to 7° angle)

A friend recently bought a 92 with a chaotic cold iddle.
As she has factory heavier springs, bigger valves but no airbleed screws, i achieve to set a correct cold iddle by playing with the shaft stop screws (especially the rear one witch must really work as a stop screw (be sure the shaft rear unit is machanically stopped by the screw)
and the trimmer one, using the low-cost CO Gutson Analyser but suffisant to set the mixture arround 3% at iddle.
Take care of you 😷 and our fabulous bikes ✌
Patrick from france