1976 350 Road

[veloduke]

George

I have a 250 - 350 Road manual (Spanish, downloaded from www.lamaneta.com) that agrees with your valve timing, and it also says the 350 has an Amal 930. I also have written down that those figures are for a cam marked SCR 2.5.

Whenever I have measured valve timing I have never managed to get exact published figures, only very close. I read somewhere (maybe the Velocette forum) that the important figure to get right is the inlet closing measurement. However I agree that your current settings seem pretty close, and you may only notice a difference on a dyno. Having said that, I have had to change the valve timing by one tooth in order to get a bike (250 Road) to run properly/tickover at low rpm. Unfortunately I can't remember what I started and finished with . Luckily it's not too difficult to change. Maybe a case of try it and see.

For what it's worth, I would fit the 27mm carb as it matches the inlet port.

I'm not an expert, it's just my experience.

[George]

Thanks for prompt reply Max. You have set my mind at rest and will leave as it is. As you say best to try it and see how it runs.
My 27 carb. is very worn. I have a new 30 carb and will use that to see how it goes.
Thanks for link Will download tonight and print a copy

[Duccout]

Hi George,

I check timing figures the same way that you do, and it would seem that your timing is a s good as it is going to be. I initially timed my 250 to the wrong dot (I did not check it at the time) and when I rode it it was obviously out as the engine ran very 'soft'. When I set up the degree disc on it, it was easy to see that I had timed it to the wrong dot.

As we have discussed before on here, the timing figures are greatly affected by all of the possible errors in the cam drive train, as well as the cam itself. Anthony Ainslie told me once that Ducati 'Green Frame' Desmos were no faster than 750 Sports because there were so many errors in the bevel train that the cylinders fought each other unless corrected with offset keyways. The fact that the Ducati factory race shop took 40 hours to build a race engine says it all really!

Cheers,

Colin

[George]

I have got the engine running in spite of a few kick backs, just a matter of showing who is boss (the bike sometimes).
It would seem that Regulator/Rectifier is not working, very erratic and over charging.
Would anyone be able to advise on replacement as I don't think original model is available. Have searched forum but not finding anything related to Spanish Regulator/Rectifier
Mototrans 350 Road 1976 with points ignition six volt Motoplat five wire
Thanks in advance of any advice

[Duccout]

Hi George,

Hans may be able to help you - maybe you can use one of the eBay Chinese regulators? If not, does Recambousio (sorry for the spelling) have anything?

Cheers,

Colin

[Jon Pegler]

Hi George,

Quite a few scooters used the 6 volt Motoplat regulator/rectifier.
If you have a scooter dealer near you they may sell a direct replacement.

Jon

[George]

Thanks for replies. Ducati Vintage have a direct replacement regulator/rectifier for widecase models. I will go with them
https://www.ducativintagestore.com/dire ... ase_models

[George]

Life's journey has its disappointments. After spending a year on Ducati 350 restoration age has caught up with me and I no longer have the strength to kickstart the bike so it will be up for sale after I add clear coat to tank, fit side tool box and filter box.
Sorry to see it go!
Moving on I still have my health and, some say, my mental facilities

[Duccout]

Hi George,

I am so sorry to hear that. I can offer a couple of solutions: what about fitting a decompresser? Or what about lowering the compression? This could be achieved by fitting a compression plate. It seems a shame to get this far and find only to find that the engine is not playing ball. What about fitting electronic ignition? This would make the bike easier to start.


Cheers,

Colin

[George]

Hi George,

I am so sorry to hear that. I can offer a couple of solutions: what about fitting a decompresser? Or what about lowering the compression? This could be achieved by fitting a compression plate. It seems a shame to get this far and find only to find that the engine is not playing ball. What about fitting electronic ignition? This would make the bike easier to start.


Cheers,

Colin

Hi Colin.
Thanks for the advice. Decompressor won't help. I can get over TDC on compression but I cannot manage to kick with enough force to get past firing stroke, kickstart stops near bottom of its stroke just before cylinder at TDC. My friend who is 20 years younger can start bike first kick every time so electronic ignition is not going to help. Lowering compression sounds a good idea. What thickness plate to fit under barrel would you suggest. I have had rebore, everything is tight at the moment, manual tells me 9-1 C/R feels higher. Bike only run in garage not on road in case it stalls.
I have no trouble starting Elite. Had a 40 mile run today to restore my inner Zen.