Another racer 350cc

[atreyu]

Heres my introduction here as Ive not posted here much before.

After having a race on a 250 we decided to start another bike so heres my 350 Duc, Its slowly come together over the last 5 months. The first outing will be 9/10th May at 3 sisters, Wigan. The bike ran for the first time yesterday, I'll be testing it on the local airfield on friday and then racing the weekend after with abit of luck.

Frame

Newly turned spindle and bushes (All machining is being done at home by my dad)

Blasted engine parts



Yokes machined from the solid

Various brackets welded on

New seat loop with rear seat mounting

New yokes complete with part of the front fairing mounting, you can just see the front tank mounting points too

Gearchange cross-over tubes


Gearbox bearings dropped in.

Gearbox bits ready for assembling/shimming etc

Dirty selector box ready for rebuilding.

Part of checking the endfloat/shimming

Frame after many hours sanding and then powder coating

Tank and seat (needs covering obviously)


Bottom end is now together, the rest is placed on. Hardly any gaskets are being used (most faces have been machined)

Heres the newly turned inlet stud, The yokes now have had a radius machined in as they looked abit crude before, Ive started to polish them too but theres alot more polishing needed.

machining of the cam tunnel.







here’s the head built up

and the engine in


Which then lead to a few more problems!
1) The carb has to be slightly twisted or it touches the frame (This was a problem on the 250 so I guess other people have this prob)
2) The fuel tap would be half way into the carb
3) Impossible to attach throttle cable
4) Choke lever fouls on frame
Choke:

Carb probs:

Solution: Have to make a piece to go in yet though.

And here’s a few pics with the tank on....






And heres the latest pictures as of yesterday, Still plenty of fettling to do and the tank still needs sorting! Also a front fairing mount would be handy!







Just hoping its trouble free now.

[DAVID.BROMLEY]

Hi a really nice job hope all goes well . Ride Safe Dee

[atreyu]

Thanks Dave,
We tested the bike at the airfield today (first time). Considering everythings new and freshly built there wasnt really any problems. Im amazed how well the bike pulls, considering the full race cam it will actually pull from nothing smoothly.

A few issues are that the crank is out of balance, this will be sorted in time for the Mallory BHR meeting, and the dry clutch has a very harsh bite, almost like a switch on or off! Has anyone else had this problem?

[Gerry]

Hi dave,
A Very neat looking bike, you have put in a lot of work.Im sure you will be rewarded in the pleasure of racing it. I know what you mean about the dry clutch, they are on or off, a friend of mine upended his lovely F3 and damadged it last weekend when we went up the drive at hoghton sprint. Racing though, as you know shouldnt be a problem once your off the line. We must get together and mabe test at your local airfield as i dont have that facility where i live. Wishing you every success on that lovely bike .
Best wishes Gerry

[atreyu]

Thanks Gerry, As I said in my PM your more than welcome to come have alook or visa versa. I didn’t have to pay to "test" but now due to a change in management at the airfield its now £25, but that’s for a full hour which I suppose isn’t too bad.
I don’t suppose you could PM me some sprint/hillclimb events because I don’t actually know of any?

I've read that dry clutches like weaker clutch springs, I had fitted 450 ones so I've ditched them in favour for some old 250 ones. Hopefully that might help, as the first race is next weekend I can only try it down the drive now.

[Monty777]

Originally Posted by britaxcooper

Thanks Gerry, As I said in my PM your more than welcome to come have alook or visa versa. I didn’t have to pay to "test" but now due to a change in management at the airfield its now £25, but that’s for a full hour which I suppose isn’t too bad.
I don’t suppose you could PM me some sprint/hillclimb events because I don’t actually know of any?

I've read that dry clutches like weaker clutch springs, I had fitted 450 ones so I've ditched them in favour for some old 250 ones. Hopefully that might help, as the first race is next weekend I can only try it down the drive now.

Dave, use 3 x 450 springs and 3 x 250 ones to start, paint one set so you can tell them apart-standard trick we used to use racing TZ Yamaha's.

John

[atreyu]

Thanks John, That’s actually what we tried, I believe the 350 ones are the same as 250 aswell. Either way it was still too heavy like that.

I've now got a full set of Condor springs in there. There’s a huge difference in strength between the 450 and 250/350/Condor ones, I’ve not tried it yet because the forks are out again, but the lever is a lot lighter.

[Gerry]

Originally Posted by britaxcooper

Thanks Gerry, As I said in my PM your more than welcome to come have alook or visa versa. I didn’t have to pay to "test" but now due to a change in management at the airfield its now £25, but that’s for a full hour which I suppose isn’t too bad.
I don’t suppose you could PM me some sprint/hillclimb events because I don’t actually know of any?

I've read that dry clutches like weaker clutch springs, I had fitted 450 ones so I've ditched them in favour for some old 250 ones. Hopefully that might help, as the first race is next weekend I can only try it down the drive now.

Hi,Dave Hope all is well and your set up for Three Sisters, . I think you must mean Elvington, having raced there its a place i know well. Didnt know about the testing arrangement which sounds really good!.I will send some sprint dates ASAP ,Dave best of luck on sunday, above all enjoy!

Race to win . Gerry

[atreyu]

Thanks Gerry, I'll let you know how it all goes, hopefully the bike will be ok. We have yet to re-test the clutch though! We're waiting for a new Interspan ignition to arrive, Hopefully it will be here, fitted and tested before we leave in the evening!

The airfield is just down the road from me, called Breighton. Its only a shortrun way but it does the job. Elvington do let you rent out their space but its a rather bumpy large square of tarmac, I dont think its cheap either.

[JerryXt]

awesome job - great.

[atreyu]

After the racing at the weekend, we have now got the crank out and have had ago at balancing it to the correct percentage.

The task seems simple but its proving to be a tad tricky, I think once the cranks had oil through it, its not quite allowing the big end to rotate as free as it should. Anyway it should be somewhere near now, it can always come out again after Mallory.

[atreyu]

I've just finished the fairing so I thought I'd post a picture up, Apparently the blue didnt stand out as well as we thought at the 3 sisters meeting.

Mallory next weekend!