Goot morgan Juergen. Yes, those numbers look right. If you really want to down-tune your bike, and you will after removing the NCR cams, then you can use any two H cams from any late-80s to late-90s 750 or 900M. You will find them marked with an R. The H will go right in, but then the replacement H cam used on your V head must be marked and timed as suggested in the answer to flattop. A set of stock Pantah cams will bolt right in (love that phrase) and be very similar in performance. When 900ss and ie cams are suggested that is because they have more lift and duration than the R cams, and are great for racing. But you say that is not what you want now. So, 750 H (O) cams are for sale and cheap, and Pantah cams are listed on ebay quite often. You could use two Paso H (o) cams (but not a V cam) since the specs are "identical" to the stock F1. This is where a review and study of Brad's cam chart really helps visualize the differences in cams.

But, if you are not experienced doing these kinds of things (or a risk-taker), and in degreeing cams, then replacement will "challenge" you.

MikeV

PS: By "down-tune", with standard cams your engine probably be out of breath by 8500 rpm, and struggle to over-rev to 9000. Be sure that will be what you want.

So if I read your post correct two of the following cams would work but I have to mark and time the accordingly:
https://store.bevelheaven.com/Engine-Re ... nt-pantah/
Is this correct?

Hi Mike...
Actually that cleared things up quite nicely. Had I tried that with only one cup of coffee in the tank, I probably would have posted a recipe for blueberry pancakes.
Thank you!
Flattop

Check with Ed Milich at Ducpower.com. He has lots of Pantah/Cagiva parts and probably a pile of 650 Allazura cams.

Thanks, contacted Ed and he came back with a very good offer on some F1 cams, will give it a try and report back.
On another note, would it be better to run the milder cam with 36mm Dellorto or are the 40mm I have right now fine for such a setup?

Juergen.

You say the valves are now 1mm larger, you have NCR cams, and 40mm carbs. It is likely the heads are ported to some degree, and the replacement manifolds (a guess) are probably matched for the larger carbs. Sounds good to me. Even Ian Falloon would approve. Pat too, l will bet.

I guess you could put smaller carbs on, but they will not easily slip onto the large Malossi manifolds (that guess, again). Or, you could down-jet the 40s. Once some things are done it may be hard to reverse them. It is hard for all of us to answer your questions without seeing what you now have in total. Things work in concert, or in packages, and disrupting them may not be better.

Why do you want to change this? Do you have "cabin fever"? Are you bored? Restless in Seattle?

MikeV

Mike -
A bit of cabin fever for sure, and restless in Seattle too! When I bought the bike I knew that the engine was set up for racing and track on not for the street. Over the last few summers I only used the bike on the street for occasional fun rides and for going to Backfire here in Ballard with friends. The engine is not set up for driving in traffic but while I considered a few times selling the bike I really enjoy riding her so I decided to get the engine a bit more suitable for street driving, hence the effort to reverse a few of the modifications.
First step is to get the camshafts replaced and then I will see how it goes, next might be to go back to the original pistons since I still have them, if that works well with the 40mm carbs (will do some re-jetting) I will leave them on I think, if not I would consider smaller ones (but as you mentioned I would also need the manifolds. Looks like Ed has some so I could get the set from him if I decide to go down this route.
- Juergen

Hello Juergen,

For what it's worth I have a 750 engine, ported and flowed, 40mm Dellorto's, and 900ie cams.
This is a street bike and is very easy to live with on public roads
(except for the riding position and noise)
Compression is up more than I'm happy with but passable with quality fuel.
My point is the 900ie cams are very tractable for the road but still ok at high revs.
Two x front cams.
Also the crank is standard weight not lightened so this possibly helps.

Regards
Graeme

Even fully de-tuned, an F1 would be a lousy bike to be putzing around town on. You're lucky to have one set up the way it was meant to be. Save it as is for riding it where it will shine, and get an Alazzurra for a back up.
Bill

the later 600/750 r cam is the f1 grind, but retarded 10 degrees. that sort of timing will help with too much comp issues by bleeding off some midrange pressure. a larger cam, like the 900ie, will do a similar thing, depending on where you set them.

if it has 40mm sized manifolds and ports then going down to 36 will help air speed through the carbs, then drop it in the ports. might help.

cams make the biggest difference. the 900 carb cam is better than the 750 r cam imo for anything, but they are much harder to get. the r cam should be almost free. i have a heap of them. they'll make it a much nicer street engine than the ncr.