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Not able to test ride the Vespa for tuning, stuck inside, I've grabbed an old 2016 malossi 210 kit to look at port timings...

Started measuring the exhaust and transfer and wanted to aim for a 190deg exhaust timing, but was wondering if the transfer needed to be raised too...

But I've never seen anyone raise transfers by grinding... seems to be raise the barrel and skim off the top and raise the exhaust...

Just thinking out loud and seeing if anyone has any experience with that?
⚠️ Last edited by 108 on UTC; edited 1 time
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From what I have read, the transfers are ground at specific angles left to right, and up, to push exhaust gasses towards the exhaust ports while filling the cylinders with a fresh fuel charge.
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Christopher_55934 wrote:
From what I have read, the transfers are ground at specific angles left to right, and up, to push exhaust gasses towards the exhaust ports while filling the cylinders with a fresh fuel charge.
So grinding the transfers on the bore side isn't really done?
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Jack is your man. He has raised transfers on his PX200 'o' tune (iron cylinder), but not sure about a lined alu cylinder like the 210
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Jet Eye Master
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Grinding transfers is delicate and difficult. Quickest way to write off a cylinder but when was that ever a reason not to do it. Apart from basic timing and direction, it's possible to adjust the phasing of what opens when.
However, skimming cylinders and adjusting packers, while less interesting does give guaranteed results.
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Jack221 wrote:
Grinding transfers is delicate and difficult. Quickest way to write off a cylinder but when was that ever a reason not to do it. Apart from basic timing and direction, it's possible to adjust the phasing of what opens when.
However, skimming cylinders and adjusting packers, while less interesting does give guaranteed results.
Love that mate, never to shy away from a challenge...

but honestly, I dont see anyone doing it with a malossi 210 sport and even skimming the top of the cylinder too...

I was thinking how much needs to be skimmed off the top to reach 190... its like 2.5mm

Then would you skim the head? but theres an O-ring to think about, and ive not seen anyone get rid of the o-ring...

Packing 1.5mm i can imagine, but how to keep the timings, i'm lost
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108 wrote:
Jack221 wrote:
Grinding transfers is delicate and difficult. Quickest way to write off a cylinder but when was that ever a reason not to do it. Apart from basic timing and direction, it's possible to adjust the phasing of what opens when.
However, skimming cylinders and adjusting packers, while less interesting does give guaranteed results.
Love that mate, never to shy away from a challenge...

but honestly, I dont see anyone doing it with a malossi 210 sport and even skimming the top of the cylinder too...

I was thinking how much needs to be skimmed off the top to reach 190... its like 2.5mm

Then would you skim the head? but theres an O-ring to think about, and ive not seen anyone get rid of the o-ring...

Packing 1.5mm i can imagine, but how to keep the timings, i'm lost
What do the numbers look like with a 60mm crankshaft vs 57mm?
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Christopher_55934 wrote:
108 wrote:
Jack221 wrote:
Grinding transfers is delicate and difficult. Quickest way to write off a cylinder but when was that ever a reason not to do it. Apart from basic timing and direction, it's possible to adjust the phasing of what opens when.
However, skimming cylinders and adjusting packers, while less interesting does give guaranteed results.
Love that mate, never to shy away from a challenge...

but honestly, I dont see anyone doing it with a malossi 210 sport and even skimming the top of the cylinder too...

I was thinking how much needs to be skimmed off the top to reach 190... its like 2.5mm

Then would you skim the head? but theres an O-ring to think about, and ive not seen anyone get rid of the o-ring...

Packing 1.5mm i can imagine, but how to keep the timings, i'm lost
What do the numbers look like with a 60mm crankshaft vs 57mm?
I imagine something like this?
Forum member supplied image with no explanatory text
Forum member supplied image with no explanatory text
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UTC quote
108 wrote:
Christopher_55934 wrote:
108 wrote:
Jack221 wrote:
Grinding transfers is delicate and difficult. Quickest way to write off a cylinder but when was that ever a reason not to do it. Apart from basic timing and direction, it's possible to adjust the phasing of what opens when.
However, skimming cylinders and adjusting packers, while less interesting does give guaranteed results.
Love that mate, never to shy away from a challenge...

but honestly, I dont see anyone doing it with a malossi 210 sport and even skimming the top of the cylinder too...

I was thinking how much needs to be skimmed off the top to reach 190... its like 2.5mm

Then would you skim the head? but theres an O-ring to think about, and ive not seen anyone get rid of the o-ring...

Packing 1.5mm i can imagine, but how to keep the timings, i'm lost
What do the numbers look like with a 60mm crankshaft vs 57mm?
I imagine something like this?
Does that include raising the cylinder 1.5mm to keep the squish the same? Any idea what you want to.get for a transfer timing number?

Interesting reading and numbers in this article.

https://blog.scooter-center.com/en/malossi-210-cc-tuning-kits-for-vespa-p-range-p200-v2008-sport-mhr-first-sight/
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Jet Eye Master
PX221 MHR, O tuned PX200, PX125 and some motorbikes
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Jet Eye Master
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Joined: UTC
Posts: 4609
Location: London UK
UTC quote
108 wrote:
Jack221 wrote:
Grinding transfers is delicate and difficult. Quickest way to write off a cylinder but when was that ever a reason not to do it. Apart from basic timing and direction, it's possible to adjust the phasing of what opens when.
However, skimming cylinders and adjusting packers, while less interesting does give guaranteed results.
Love that mate, never to shy away from a challenge...

but honestly, I dont see anyone doing it with a malossi 210 sport and even skimming the top of the cylinder too...

I was thinking how much needs to be skimmed off the top to reach 190... its like 2.5mm

Then would you skim the head? but theres an O-ring to think about, and ive not seen anyone get rid of the o-ring...

Packing 1.5mm i can imagine, but how to keep the timings, i'm lost
The packer on the base is only used to adjust the transfer ports. On an MHR with a 60mm crank, somewhere between 125 and 135 is often possible. Sport is a bit less. Exhaust port always has to be ground to get the duration up. Grinding exhaust ports is easy/easier, once you have done it once, and felt the difference it makes, you'll grind every cylinder you have.

Port timing is more important than squish but only just. Can be quite a juggling act with all the packing and skimming.
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UTC quote
Jack221 wrote:
108 wrote:
Jack221 wrote:
Grinding transfers is delicate and difficult. Quickest way to write off a cylinder but when was that ever a reason not to do it. Apart from basic timing and direction, it's possible to adjust the phasing of what opens when.
However, skimming cylinders and adjusting packers, while less interesting does give guaranteed results.
Love that mate, never to shy away from a challenge...

but honestly, I dont see anyone doing it with a malossi 210 sport and even skimming the top of the cylinder too...

I was thinking how much needs to be skimmed off the top to reach 190... its like 2.5mm

Then would you skim the head? but theres an O-ring to think about, and ive not seen anyone get rid of the o-ring...

Packing 1.5mm i can imagine, but how to keep the timings, i'm lost
The packer on the base is only used to adjust the transfer ports. On an MHR with a 60mm crank, somewhere between 125 and 135 is often possible. Sport is a bit less. Exhaust port always has to be ground to get the duration up. Grinding exhaust ports is easy/easier, once you have done it once, and felt the difference it makes, you'll grind every cylinder you have.

Port timing is more important than squish but only just. Can be quite a juggling act with all the packing and skimming.
I've ground exhaust ports horizontally just as an experiment after seeing the old asso worb5 tuned cylinder... but never extended the timings...

Im just thinking about the timing difference between the transfers and exhaust... do i need to keep the "difference" between the 2 timings, or the ratio of the timing difference...?

I have a bunch of malossi 210 packers from an old setup i can use to raise the transfers, but wondering how much would need to be skimmed...?
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