860 gt wet rear plug adjustment question

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Tinkerbell
Mariana
Posts: 47
Joined: Sat Sep 05, 2020 3:57 am

860 gt wet rear plug adjustment question

Post by Tinkerbell »

Hi all,
Just tuning up after rebuilding phf32s. New needle valves, seats, enrich plungers, etc. Bike starts easily but wets rear plug in 5 minutes. Question is...can the idle fuel adjustment allow such a rich condition that it wets a plug.?? Have drained bowl into measured breaker and see about 50 ml.
Thanks,
Kara
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81mhr900ss
750 GT
Posts: 172
Joined: Tue May 31, 2016 3:49 pm

Re: 860 gt wet rear plug adjustment question

Post by 81mhr900ss »

I'd say no if set right. The obvious things to check are float bowl height, good seating of the choke plunger and a clean air filter. These bikes will run quite easily on one cylinder which masks problems with individual cylinders. When you set up the idle screws, could you hear the difference in engine sound and revs when tweaking the idle screws? Its rather subtle at lower rpms. I start at 1.5 turns out from closed and set the idle at around 1800rpm first and then drop it in steps to around 1000-1100. I have MotionPro vac gauges now for balancing and tweaking the idle screws too; I used to do this all by ear and feel.
Tinkerbell
Mariana
Posts: 47
Joined: Sat Sep 05, 2020 3:57 am

Re: 860 gt wet rear plug adjustment question

Post by Tinkerbell »

Hi MHR.
I just got the carbs rebuilt and back on the bike. I am new to Dellortos and Ducati---have just started the tune and adjustment process. I was trying to see if you really had the idle screws wrong--would it lead to flooding. I will get into it tomorrow. I am cleaning the air filters now. The bike is new to me and there is some catch up to do. Not to mention that the end fell off of the gearshift lever. I am making a prosthesis for it tomorrow morning. It will not be allowed to break again.
Thanks,
Kara
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ashleyf
Cucciolo - the Lil Pup
Posts: 17
Joined: Sat Aug 22, 2020 11:36 pm
Location: Sydney Australia

Re: 860 gt wet rear plug adjustment question

Post by ashleyf »

Wow. I have not had a Duke for 20 odd years and sold the '78 900 then.
I was unhappy with the overall running and handling and was determined this time around to fix the niggles. I lack the rtechnical expertise, but not the appreciation of what needs to be done.
Building prosthesis ? What an ability. I am still looking for a dog leg brake lever that will fit my hands so I can two finger cover. Will probably have to get it CNC machined. $$$


Your thread (s) and MHR81's input have given me hope that I will have a bike to keep (and ride) this time around.

Thks for posting , both of you.
1976 900 SS. Sydney OZ.
Tinkerbell
Mariana
Posts: 47
Joined: Sat Sep 05, 2020 3:57 am

Re: 860 gt wet rear plug adjustment question/ Ashley

Post by Tinkerbell »

Hi Ashley ,
I have never had a Ducati before and this one is requiring some sorting out , although my impression is that it is basically sound . I spent some time sorting out my 75 Commando and this summer it was finally in decent working order. I bought the Norton two years ago and I had not had a bike for 30 years. I think one must become to a large extent one's own mechanic. I like knowing the state of things on the machine and having had my hands in it. I am not sure with a vintage machine if there is any real alternative.
The toe angle with the rubber broke off my gearshift, so I was able to machine a block with a hole down its length that is pretty close to the oval cross section of the stem of the shift lever. I put three set screws in the bottom and drilled a right angle hole and a shoulder bolt now carries the rubber and engages your toe. I engraved "Ducati" on the side of the block and now it is some strange imaginary factory part. My Norton got infested with odd aluminum pieces that I machine and its all in good fun.
Keep chipping away at it!
Kara
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