DUCATI TT and F1 FORUM
 
It is currently Mon Jun 26, 2017 4:39 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 5 posts ] 
Author Message
 Post subject: Parts interchangeability late to early 2 valve engines
PostPosted: Mon Oct 18, 2010 3:46 pm 
Offline

Joined: Thu Oct 14, 2010 1:39 pm
Posts: 19
Images: 15
Location: UK
Hi to all on the forum, hope it grows into a useful resource for the F2/TT2/TT1 restorer & replicator. With so few genuine Duc TTs about I guess most of us will fall into the latter category.

I'm a relative newcomer to Duc L twins & really only got into them about 6 years ago to have an affordable classic trackday bike for events like the "Bikers Classics" at Spa & UK based events such as the 1000Bikes etc. Of course once I rode one I was smitten & I now co-own several - a standard framed 600 F2 replica, Harris 750 TT1, Verlicchi style 750 & an F3 with a 650 engine.I'll post some pix when I figure out how...

Spares can be a problem & upgrading an old engine to endure the abuse it will get on track (rather than tuning it) is something I'd like to do. So it would be ideal to know which modern (read "easily available") Duc spares can be retrofitted to early engines to either replace or upgrade 30 year old parts. It may be that some will fit straight in or maybe require a bit of modification. Thats the info which would be useful to those of us not in the know.

On the other hand we might have the situation that something will seem to fit but will result in problems. I know that some barrel & crank combinations can lead to 5;1 or 15:1 compression ratios & small valve heads & big valve pistons don't like each other a lot....

Whilst tuning might not be ideal on older engines I'm sure there are mods we can do to make our Pantah based engines run better & this too is an area for the experts out there to pass on the knowledge - how to fit an oil cooler to an early 500/600: are variable timing pullies worthwhile; what alternative is there to the "boiled in oil" Bosch pickups.

Hoping to learn something! Regards Mike


Top
 Profile Personal album  
 
 Post subject: Re: Parts interchangeability late to early 2 valve engines
PostPosted: Thu Oct 21, 2010 11:33 am 
Offline
User avatar

Joined: Sat Oct 02, 2010 12:22 pm
Posts: 126
Mike,

Hang in a bit on that one -- it's a broad topic and a good one. Possibly the best way to get things going is to start with a specific component like you did with the Bosch pickups which can be upgraded to Kokusan if the whole system is replaced. What's more, you have several compelling reasons to go that way that are all related.

The Microclassic ignition is also worth a look while considering Pantah options.

More in a bit.

Fran


Top
 Profile  
 
 Post subject: Re: Parts interchangeability late to early 2 valve engines
PostPosted: Sun Oct 24, 2010 2:30 pm 
Offline

Joined: Tue Oct 05, 2010 9:21 am
Posts: 208
Images: 0
With Frans opening I,ll take the lead (pun intedned) and expand on the igniton topic. The old Bosch system is really not that bad a system. The issue with it is the pickup-leads in the engine that deteriorate and the week coils. The pick-ups should be rewired with hi temp leads making sure to keep the polities correct. Coils can be replaced wtih the famous green dyna coils but the new Dyna minis in 3 ohm (2.4 actual) are a better fit in the limited space. These old bosch systems are used with sucess in many a vintage racer still and for the most part are durable. The Kocksan system is an upagrade but as Fran mentioned needs a complete system replacemnt. Same recomendation to up grade on coils. The advane cuve is linear and not stepped like the bosch. It actually helps in the lower RPM/ street appliaction. Programables I have not played with yet. The up side would be optimizing for more radical builds. The down side would be the expense of having spares in the "just in case tool box".
What is everyone running for plugs in styles and heat ranges? Fran, Im that smart %$#@ that used to ask if I needed hotter or colder plugs in Canada!


Top
 Profile Personal album  
 
 Post subject: Re: Parts interchangeability late to early 2 valve engines
PostPosted: Tue Oct 26, 2010 11:54 pm 
Offline

Joined: Wed Oct 13, 2010 10:32 pm
Posts: 84
Images: 6
What year or model was the change made to kokusan ignition system.

thanks Marc


Top
 Profile Personal album  
 
 Post subject: Re: Parts interchangeability late to early 2 valve engines
PostPosted: Wed Oct 27, 2010 7:03 am 
Offline

Joined: Thu Oct 14, 2010 7:07 am
Posts: 1
The switch to Kokusan occured during the 1986 poduction run. Some early built 86's retained Bosch.
Rich


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 5 posts ] 

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: 618F1 and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
Template made by DEVPPL