Holes in piston for reed conversion

[Dazza]

No boost port on the basis that I can revert back to the original piston port if I cocked it all up .

I've got to get it on the road and see how things go really... Watch this space

[Wack]

The "crack "noise is most likely caused by the reeds especially if they are the stiffer variety.

[Dazza]

I did think that myself wack, maybe it'll soften up with use hopefully , I've just re packed my exhaust and the carb makes more noise than that now

[Wack]

They tend to sound louder especially if the reed block is plastic compared to rubber coated alloy ones.

[Dazza]

I think it is plastic

[skinnerwill]

please keep updates coming. I have a lth reed valve to fit and piston to cut (when it gets a bit warmer in garage)

[Dazza]

Update... I went out on it today and the results - crap

Hard to start, kept bogging down, misfiring when at a constant speed and kept having to change down ..but essentially crap.

So I'm assuming now that the window in the piston is way too big.

I half expected to cock it up to be honest , that's why I used the old piston just incase.

I'm now going to send the barrel off to someone that knows what they're doing, have the barrel matched to a new oversize piston that's been machined correctly and then go from there... Onwards and upwards

[Wack]

Unless something is seriously wrong with the piston I wouldn't have thought it would give the symptoms you describe. For a start you will need to alter the jetting . The reeds now dictate the induction, only opening when the vacuum is high enough and closing when it drops so even if half the piston skirt was removed it should still run .

[Dazza]

It does seem like it's overfuelling , but it did run ok beforehand , I appreciate it will need jetting to suit but it can't be that far out from what it was originally can it?

The 'cracking' induction noise is bothering me though, it's really loud especially out on the road

[Nelly]

Scotty did mine for me, standard Jet 200 barrel with atomic reed conversion.
Had it out today trying to sort jetting and it's pulling really well. Still fine tuning though, there's a bit of a lean spot in midrange to address.
Drop him a message, I'm sure he will advise you what the best approach is for you.

[Norrie Bodge]

Scotty did mine for me, standard Jet 200 barrel with atomic reed conversion.
Had it out today trying to sort jetting and it's pulling really well. Still fine tuning though, there's a bit of a lean spot in midrange to address.
Drop him a message, I'm sure he will advise you what the best approach is for you.

hi m8
gotta similar setup in my GP how much have you gone up/down with main jetting compared to before you fitted the reedvalve setup?

cheers

[Nelly]

It's a bit hard to say, as I changed carbs at the same time. I went from an Amal 30mm to a OKO 30mm, to a Dellorto PHBH 30mm. I gave up trying to set up the OKO, which is a PWK/Keihin copy. I've also changed from SX200 gearbox to Indian GP200 gearbox and changed the Scorpion expansion for a MRB Clubman too.
At the moment the Dellorto is set up with a 125 main, 50 pilot, x7 needle (3rd clip down) and AV266 atomiser, 40 slide, 300 float needle. It's close but not quite right yet.
Took it out today to get a few miles round town, it has quite a bit power but I'm suspecting it's still a bit lean in mid range.

[Norrie Bodge]

It's a bit hard to say, as I changed carbs at the same time. I went from an Amal 30mm to a OKO 30mm, to a Dellorto PHBH 30mm. I gave up trying to set up the OKO, which is a PWK/Keihin copy. I've also changed from SX200 gearbox to Indian GP200 gearbox and changed the Scorpion expansion for a MRB Clubman too.
At the moment the Dellorto is set up with a 125 main, 50 pilot, x7 needle (3rd clip down) and AV266 atomiser, 40 slide, 300 float needle. It's close but not quite right yet.
Took it out today to get a few miles round town, it has quite a bit power but I'm suspecting it's still a bit lean in mid range.

cheers on the reply Nelly m8
iv just txt scotty, he said normally you`d go higher on the main jet, so i will try bigger for starters
im running with a 30mm Amal for now, will prob change to dellorto later in the year as me spending been crazy lately

[Dazza]

Just a thought, I repacked the jl3 end can at the same time, I noticed the internal tube was loose, I think it was on its last weld , I carefully wrapped the wadding round thinking it may be ok for a while , when I put the end cap on i had to use a bit of force to get it to fit.

I wonder if the tube has come away and partially blocked the exhaust ? I reckon it would cause the running issues - would it also explain the noise out of the carb - exhaust pressure coming out the carb ??

Long shot maybe?

[coaster]

Definitely worth a look for the sake of renewing a few rivets. As far as the 'cracking' noise is concerned, I ran an Indian SR style 225 barrel with an MB short manifold for a year or so and never heard it do that, nor the TS1 I replaced it with

[hullygully]

did you torque your cylinder head down? I had a TS1 that 'cracked' when revved, it was a very loose cylinder head, still run tho'

[Dazza]

Another quick update, I've fitted an avanti TS1 piston now and all seems good .. Just got to sort out the jetting now as it's not quite right at tickover and pulling away.

I rather embarrassingly have to admit I found the main reason for it running crap initially was the fact that I hadn't re- connected the agusto

It still needed the piston changing though , I'm happier with that in

[Dazza]

I've hardly used the scooter this season for one reason or another but went to Mersea last weekend so the first test for the new setup.
I was chuffed to bits on its performance , felt a lot crisper with more torque, uses a lot less fuel and makes a lot less mess under the panels.
Top speed hasn't improved - 65mph gps but I'm very happy.

A little bit of jetting to play around with as it 4 strokes a lot on roll off