Fitting a Dellorto carb on a 250 Trophy Sport

[moriniboy23]

Ive got a non-starting 250 Trophy Sport and its been suggested it could be carb issues

Has anyone tried a Dellorto slide carb rather than the usual Mikuni conversion? ive got several spare Dellortos, 26s & 28 PHBHs which are often fitted to Aprilia 2-stroke singles, so Im loath to spend £150 on a Japanese carb if I can just buy a handful of jets and a 2-stroke atomiser instead and pursue this avenue

If anyone has done it and can give me a jetting heads-up Id be really grateful

Simon in Bath

[stogadog]

Don't want to teach you to suck eggs but have you thoroughly tested the ignition system first? - I would have thought that unless the carb was completely blocked up it would at least start up if not run properly providing you were getting a decent spark.

[moriniboy23]

Ive got a newly rebuilt engine, with measured squish, timed-up and clean points, a west german coil, new HT lead, a handful of plugs, new fusebox, cleaned-up earthing point and an extremely blue spark, so I PRESUME the ignition isn't the problem...
I presume....

[breakwellmz]

Hi

The petrol isn`t old is it?2 strokes in particular don`t like old petrol.
It was a runner in your hands before was it?

Cheers
Martin,Twerton,BATH.

[moriniboy23]

Forgot to list that, that the petrol & 2-stroke is brand from the garage

[breakwellmz]

Does the plug look wet after you have tried starting it,as in petrol is getting in there?

Don`t mind coming over to have a look as you are local to me if you want,do PM me if you want to.

Cheers

[moriniboy23]

Ive sent you a couple of PMs so as not to clutter the board. Have you had them? My email is: moriniboy23@yahoo.co.uk and phone 01225 834235/ 07788 442155

[breakwellmz]

Hi

I`m doing this tomorrow you know about it i assume?Then the Moto GP starts on Sunday!

http://www.twotunnels.org.uk/

[therealche]

Hi
Then the Moto GP starts on Sunday!

http://www.twotunnels.org.uk/

Can't wait... looks like all 3 classes are going to be good this year! Look's like "Darling Dani" is in for a nasty surprise!

[breakwellmz]

Ive sent you a couple of PMs so as not to clutter the board. Have you had them? My email is: moriniboy23@yahoo.co.uk and phone 01225 834235/ 07788 442155

Hi

Sent you a PM yesterday,but it is shown as being in`outbox`rather than`sent`.What is the difference,and have you received it?

Cheers

[moriniboy23]

Ah no not received it, wait, it does say 'one new message'. I wish this site would inform one's email about a new message... of course, the Two Tunnels thing. I forgot all about it. It goes under my house...I wanted to go to that festival, curses. Enjoy the bike racing, speak

[breakwellmz]

JUST came across this which may be useful-

http://www.dgw.org.uk/downloads/ts250-manual-image.pdf

[moriniboy23]

Yes got an original and the ETS supplement. They are somewhat better than the Haynes equivalent...

[breakwellmz]

Re your message.

Good spark,presumably at the right time,fuel(Fresh),compression.What else do you need?

That`s the good thing about 2 strokes,SO simple

You COULD have a crankcase full of fuel is suppose,or a spark that breaks down under pressure.

Have you tried bump starting,or just on the kickstart?

Come on chaps,anyone else here have any ideas?

[moriniboy23]

Having been lent a 'good' 28mm carb, the bike eventually started - Eureka last weekend, and after it cleared itself (sorry neighbours) would rev out.

When I took the old carb off to put the borrowed one on, I noticed the little rubber 'pill' that sits in the choke piston/plunger was 90 degrees out, like a coin on its edge, so it may have been this all along, permanently blocking the choke airway, even with the plunger raised. So I have either cracked it, and can put my old wrong size 30mm carb back on, or it may be that I do need another carb