Worthwhile upgrades to an early '90's 2V carbureted 900 Ducati engine?

[PhilB]

Looks like I'm finally facing a rebuild; what upgrades have y'all found to be worthwhile? Do any of you have experience with the 944 big bore kit? How about the Keihin flatslides? 39mm vs. 41mm? Any other really good upgrades for an early '90's 2V 900 Duc motor?

I will still be using it for daily transport, so while more power would be great, I don't want to turn it into a cantankerous beast that's a PITA to start in the morning or to ride in traffic or for a few hundred miles in a day.

PhilB

[Builtgypsy]

If Ducman851 is still around, you might want to shoot him an e-mail or PM and see what he has to say.

Just think, having your bike in for a major service would give you a perfect excuse to get that 998 to ride around on.

[stevo_x]

I know nothing about this I'm just trying to get my name on every thread on the new post link right meow

But serious huge props to you for riding your Duc that much! I want 10k a season minimum when I bought my bike and I'm at 10k for 3 seasons....I had some walls I had to face but I should be at least at 20k by now!

[OldSchlPunk]

You looking to do this before you go back to Cali?

I can't say I have any ideas either. Is it just a top end you're looking at?

[blurr]

Cam is paramount to making a motor, many people put a big bore kit in without adjusting a cam set for said upgrades and will not notice much, actually if possible skipping the big bore and sticking to just a cam upgrade will be your best performance bet, and for what you are doing, would probably be more so worthwhile.

[Süsser Tod]

I wouldn't add any "upgrades" to the engine, as well, all of them take a hit on rideability, reliability and/or durability. Nothing beats CV carbs for smoothness and MPGs, cams also end up moving the powerband higher and losing low end and smoothness, and big bore kits are also known to decrease durability due to the extra heat. Maybe suspension, exhaust or brakes.

Well, if I were facing an engine rebuild, I would also look into having the engine blueprinted/balanced, for increased smoothness and reliability, the extra wee bit of performance would be a bonus.

[blurr]

nah a cam that is a step up from where Phil is now would give him extra punch and with the way a V twin is set up he really would not be losing anything noticeable down low. But it really depends on the grind as to what power you are getting where. Example dragging cars there was a pretty big bunch that liked to use RV cams, which are low torque truck cams, while some liked higher reving cams. Both of course added more, just in different area's.
but I think going basically stock would seem like a modification to him anyhow a he has been riding that tired engine for a long time so its gonna be FRISKY!!! no matter what.

[PhilB]

Originally Posted by OldSchlPunk

You looking to do this before you go back to Cali?

I can't say I have any ideas either. Is it just a top end you're looking at?

Looks like I'll need to. I don't have confidence right now that it would get me back to CA. And it's the bottom end I'm mainly concerned about, but those are durable and overdesigned, so there's no need for upgrades there; just inspection and bearing replacement, I'm thinking. The top end question has to do with the possibility that I may need that as well, so I have some idea of what to do if that is the case. If my top end is still good as is, I'll just keep it. I do think I need carbs. They were worn, and I had them rebuilt, but the results have not really been satisfactory.

PhilB

[blurr]

I have rebuilt stacks of carbs and they just get, well, loose, they work, but like you said, that is about all you get out of em. Its going to be all new when you get done, spend a little extra and you will be far more pleased in the long run.


Now about a paintjob.........................

[OldSchlPunk]

At the age your bike is, if the carbs are original, I'd say stick a fork in them, they are likely done.

What makes you think you need to go into the bottom end? I agree that Ducati bottoms are very stout. When was the last time you freshened up the top end?

If you do go with the 944 kit, watch your deck height so your compression ratio doesn't rise too much, especially with an air-cooled engine. I'm not overly familiar with Ducati engines, is that a slip-in kit, or do you have to machine the heads/cases to accommodate the jugs? It's been so long since I did a VW engine, I can't remember how big an increase in bore we could go before having to machine things - I know it wasn't much because the cylinder walls weren't all that thick. I'd assume Ducatis are similar.

I guess the above would be necessary if you're doing the rebuild, or are you having someone do it for you?

One more question, what's your timeframe? Aren't you heading back to Cali soon? If now, you should be. I'm starting to think we're going to have an early, long winter - I've seen too many geese already.