Bunch of beginner questions

[swooshdave]

Here's my intro thread: viewtopic.php?f=56&t=4019







I have some basic questions, and then would like some information about the bike. The previous owner passed away so I wasn't able to ask these from someone familiar with the bike. I perused the owners manual too.

1. Fuel petcocks. I believe each carb has it's own petcock. And they are each run/reserve/off. Which is which?

2. The mods I know of are: trimmed rear frame loop, instrument panel replaces by a speedo only bracket, Conti or Conti-styled mufflers (they appear to be stainless), K&N filters, removed turn signals, twin pull throttle, and I think lower handlebars. And I'm not sure if the seat is stock or not, I think no.

So far I've only ridden it a few miles home and I had the biggest grin.

Amazingly it was actually more comfortable that my other bike.

[Craig in France]

Welcome Dave.

Looks good - it seems to have been well cared for. Seems to be an early ( = 1975) GT with what Ian Falloon calls “the lower seat option” (and with the rear frame cut off, as you say). The frame and engine numbers would confirm.

It’s lost its striping on the tank and guards, so I guess it’s been re-painted at some time. The chain guard would have been black, btw, as would the top and bottom triple trees. The headlight looks like a replacement, too. And, yes, those are lower bars.

Fuel taps: best way is to simply take the hose off and see what happens; but normally it’s back for off, down for on and forward for reserve.

The instrument panel was probably ditched because it cracked - they always did. Replicas are available from Damien at Bevel Rubber, http://bevelrubber.com.au/cart/index.ph ... 0u45m1fll2; but then you've got to replace the panel wiring and the rev counter, so I can't think it would be worthwhile.

The weak point in these engines is reputed to be the ignition which, by delivering full advance too soon, tends to stress the big ends. So, if you're thinking of keeping it, you might want to look into fitting a modern ( = more reliable, programmable and therefore gentler) after-market system, e.g the Sachse system which gets good reviews: http://www.elektronik-sachse.de/index_en.htm

But a nice bike. Definitely one to enjoy!

Ciao

Craig

P.s. Don't forget to change the oil frequently - no filter system on these beasts. Bu you knew that, I'm sure ...

[swooshdave]

Thanks for the great info.

I figured I could pull the fuel lines to check flow but it's less messy to ask here first.

I need to check the serial number but I believe it's a 74.

The good news is that all the parts that were removed (mufflers, instrument panel, tach and even the frame loop that was cut off) came w the bike. The only thing I don't see is the airbox.

I do want to see what kind of ignition is in it, I'd be surprised if it was stock.

Don't these engines have a small oil filter on the top of the case? There's a spare in the tool tray.

[Craig in France]

I figured I could pull the fuel lines to check flow but it's less messy to ask here first.

Ah, that is true! So fair enuf ...

I need to check the serial number but I believe it's a 74.

The factory's 'Build Year' actually started in the September of the previous year, after the workers' return from the annual holiday (= factory close-down) during August. So all the early GTs were 'listed' as 1975s. But I see Fallon reckons 1,671 GTs were actually built in '74. Be interesting to know the first registration date of yours, if you have it.

The good news is that all the parts that were removed (mufflers, instrument panel, tach and even the frame loop that was cut off) came w the bike. The only thing I don't see is the airbox.

Blimey, that's unusual - altogether, good news! So, just out of interest: is the instrument panel still ok?

Don't these engines have a small oil filter on the top of the case? There's a spare in the tool tray.

Yeh, but it's really only a partial filter, not a full flow job which would have required major re-plumbing. Instead, Ducati simply made use of the old points housing from the 750 while retaining the old system of cleaning the oil using centrifugal traps on the flywheels. Here's how the oil flows around the engine.



Better than nothing, tho'. Change every 2 or 3 oil changes.

Ciao

Craig

[swooshdave]

I need to check the serial number but I believe it's a 74.

The factory's 'Build Year' actually started in the September of the previous year, after the workers' return from the annual holiday (= factory close-down) during August. So all the early GTs were 'listed' as 1975s. But I see Fallon reckons 1,671 GTs were actually built in '74. Be interesting to know the first registration date of yours, if you have it.

Over here we don't track the vehicle history very well. Usually all you know is the history from the previous owner (unless they keep those records).

Blimey, that's unusual - altogether, good news! So, just out of interest: is the instrument panel still ok?

I looked at it yesterday. It's in pretty good shape but the top half is chewed up where it mounts. Not sure what happened there. Chances of it going back on the bike are nil.

Does anyone make a bracket that holds the tach and speedo?

[abmartin]

Fuel taps: best way is to simply take the hose off and see what happens; but normally it’s back for off, down for on and forward for reserve.

You have probably figured this out already but on my SS with similar taps forward is off, down is on and to the rear is reserve. The right side tap feeds the horizontal cylinder, the left the vertical. There is a cross over pipe connecting the two taps.

Cutting off the rear frame loop and substituting a GTS saddle was a common modification back in the day. I am embarassed to say that I did the same thing when I had an 860GT.

Bruce

[swooshdave]

851609 so I'm guessing that makes it a 1975 and a later 860GT.

I might get out this weekend and check on the ignition.

I need to get turn signals on it (illegal for post-72 bikes here) so I'll find some nice LEDs.

[Craig in France]

851609 so I'm guessing that makes it a 1975 and a later 860GT.

Sounds right. Ian F has both frame and engine numbers as starting at 850001; and Robert Miller's list on Steve's site lists three very close siblings (exact proximity depending on whether your number is for the frame or the engine). All are listed as 860 GT 1975 and all are in the USA.

Engine #: 851604, no frame #
Engine #: 851607, frame # 851589
Frame #: 851611, no engine #.

(To see the list, go http://www.bevelheaven.com/, then Technical Info then Data Index. And if you want to add yours to the list, e-mail Robert at [email protected], giving some or all of:
Model
Year
Motor No
Frame prefix
Frame No
Frame suffix
Owner / note
Location)

[swooshdave]

Yes, that's were I looked.

[eternally_troubled]

You have probably figured this out already but on my SS with similar taps forward is off, down is on and to the rear is reserve. The right side tap feeds the horizontal cylinder, the left the vertical. There is a cross over pipe connecting the two taps.
Bruce

My 860GT fuel taps - pointing forward = off, pointing down = on, pointing backwards = reserve. Probably the most important point is to remember to turn them off when you stop..... and then to turn them on when you start going :)

[swooshdave]

You have probably figured this out already but on my SS with similar taps forward is off, down is on and to the rear is reserve. The right side tap feeds the horizontal cylinder, the left the vertical. There is a cross over pipe connecting the two taps.
Bruce

My 860GT fuel taps - pointing forward = off, pointing down = on, pointing backwards = reserve. Probably the most important point is to remember to turn them off when you stop..... and then to turn them on when you start going

Fortunately the bike has a built in reminder feature when you forget to turn to the taps back on. Don't ask me how I know...

Question, if there's a crossover on the fuel lines then why is there two reserves? Do you guys run both taps open all the time?

[abmartin]

Both taps need to be on.

Your photo reminded me of one of the last times I rode my 860GT. I was joined by a friend on a Norton Commando. During some spirited riding he ended up in the ditch, an accident which caused the gearbox to jam. He suffered the humiliation of riding home on the back of my Ducati for a distance of 100 km or so. Within a week he bought my Duke and sold his Norton along with an attic full of spares. He had no regrets.

Bruce

[swooshdave]

Both taps need to be on.

Your photo reminded me of one of the last times I rode my 860GT. I was joined by a friend on a Norton Commando. During some spirited riding he ended up in the ditch, an accident which caused the gearbox to jam. He suffered the humiliation of riding home on the back of my Ducati for a distance of 100 km or so. Within a week he bought my Duke and sold his Norton along with an attic full of spares. He had no regrets.

Bruce

So it was his fault he crashed? Then he got rid of the Norton and got a Duc? Sounds like he just needed a slower bike.

[abmartin]

Quite the contrary. He couldn't keep up the pace and, besides, he was tired of constantly fixing his Norton.

Bruce

[swooshdave]

Quite the contrary. He couldn't keep up the pace and, besides, he was tired of constantly fixing his Norton.

Bruce

Like I said it was probably the rider's fault. No reason a good Commando couldn't keep up except if it wasn't maintained or the rider was insufficient.