hi mi looking for a single carb to suit a 1641 twinport please

Hi Tone, if you have got a twin port engine, the standard 34 pict carb will work fine, if you want more power, it is best to go for twin carbs. If you go down the twin choke single carb route, you always have problems with carb icing but you can get that with a standard carb without a warm air feed.

Rob

hi it was a 1300 but brought 1641 big boar kit will this still work

Did you fit a 1600 inlet manifold or is it still the 1300 one? What carbs fitted at the moment?

hi its stll the 1300 one twinport think its a solex 30

Unless you want to change manifold you're limited to a 30/31 carb then. A 1641 will still run fine on one of those though.

so i could keep my carb for the time being how do i no what manifold its got

The outside diameter of the 1600 TP manifold is about 35mm and the 1300TP is about 33mm. So the 1300 one is a bit restrictive at top end but drives better on say up to 3/4 throttle.

As well as the central manifold being different sizes, the end bits that go to the cylinder head are different sizes as well but it is possible to grind the ends out to match the 1600 manifold. A 1600 34 pict carb will not fit on a 1300 TP manifold without an adaptor plate. I would not recommend this route! as the smaller manifold will not let the larger carb work very well.

From what I have read, the best carb to put on your 1300 manifold (if that is what you have got) is a Solex 31 pict-3 They are very tuneable and you can pick them up for £25 and I could give you an idea on jet sizes if you went down that route.

Twin carbs are always best if you want the maximum from your engine but some are expensive. The twin solex's, off the fast backs variants etc are the cheapest and work quite well.

Hope this helps, Rob

Hi thanks what jet size would I need also can I keep the timing the same as it was on 1300

Put it on 'as-is' now and see how it runs, it should be fine, they're very forgiving carbs and very simple engines.

Thanks for your help the only thing I'm stuck on is will the timing stay the same as it was when running 1300

Thanks for your help the only thing I'm stuck on is will the timing stay the same as it was when running 1300

Yes, set it with a strobe to 28-30 degrees BTDC when the dissy's fully advanced at around 3000RPM.

Thanks a lot for all your help mate