175 iron kits...

[Andie]

Hello. I'm curious as to what other members get from a solid 175 kit.

mine, a heavy old Li3, has a 22 jetex (dynoed and set up) and a 42 clubman. casatronic stator (strobed and set). Head nice and tight. It starts second kick always and happily runs all day (I did Brid fine from leeds) but is somewhat slow, 70kph downhill - 125 gear box with a 81 iwis chain and 17 front sprocket. Nippy at the lights Cruises at 60 kph/42 mph... perfect town scoot...

my question is, whilst I am happy with it, is this a good average speed?

Thanks

[CHRIS in MARGATE]

Slow.
Should rev to 6000 rpm and get 60mph downhill and 50 mph cruising at 5000 rpm.
May well go faster with 16 front sprocket which would allow it to rev.

[Bilko]

Mine was slow, so slow I was overtook by a tractor on the way to Scarborough in 2005.

[johnnyXS]

as Chris says that doesn't sound right at all.

Like you I have a series 3 (LiS150 Special )but with a 150 engine standard exhaust and 22mm Jetex with a 5889-2 atomiser and 106 main jet.

I haven't had my new speedo calibrated or checked but my indicated cruising speed is around 48-53mph on the flat with lots in hand

My feeling is your static timing may be retarded or there is something wrong with your porting.

Are you sure you are using a 175 cylinder with the right piston and port timing ? Hows your compression , air filter flow, fuel flow rate etc

What is your final drive ratio ? it might be a gearing problem if your engine is performing ok with plenty of power

[Phil D]

Hi Andie
I think I mentioned to you before we have similar set ups .
The only real difference is I run with a 16 tooth front sprocket as mentioned .
I've not measured mine flat out but a few months ago I set the gps on my phone and I got 57.9 mph
I think it had a bit more left but as you say this set up is ideal for round town and the odd
Local rally .
If you want to go on long touring journeys I think your probably looking at a expensive rebuild or another engine .
It can start to get a bit expensive to say the least.
It all depends on what you want really but an li 125 will always be a bit limited As somebody recently told me there no substitute for cc's.
From what you said before you had it set up professionally I wondered what their take on it was ?

[EddieStone]

I have a 175 kit, with a 20mm carb through the air box and KBR clubman exhaust.

I changed the gearing to 16x46 with a standard 150Li gearbox. It pulls well around town, and hold 60mph along a dual carriageway.

I use an air filter and have an air scoop with no restriction. The air box still has the curly pipe thing in it, I'm planning on changing it to see if it will rev on a bit more. At the moment it tops out about 6000rpm.

I would expect yours to go faster, but it depends if you've opened out your ports? If it's bored out but still has the 150 ports it'll be slower. Also the inlet manifold should be opened out a bit.

Mine returns about 60 - 70 mpg which I'm also pleased about. Aim for a TV175 spec, that was Innocenti's best for performance against economy and reliability, imo.

[Hammer RB230]

Gents I have been following this discussion with interest.

I have a Li 150 with a 175 kit. The engine specs are : 22mm Jetex, AF Rayspeed Clubman, Air box restriction removed and a BGM Performance fitted. Standard gear box with a 17 front sprocket.

Apologies I can't remember the jetting however I know the main was large due to the air filter. On the dyno its putting out 9.5 BHP.

Now that its run in ,performance wise good acceleration and it feels that it will do 50MPH all day but on the dual carriageway top speed is about 55MPH with 60 MPH downhill if I'm lucky. Ive always felt that it will not rev high enough to reach a better top speed. Perhaps the front sprocket is the answer ? I was concerned that changing it would just slow it down !!

[Scooterlam]

Gents I have been following this discussion with interest.

I have a Li 150 with a 175 kit. The engine specs are : 22mm Jetex, AF Rayspeed Clubman, Air box restriction removed and a BGM Performance fitted. Standard gear box with a 17 front sprocket.

Apologies I can't remember the jetting however I know the main was large due to the air filter. On the dyno its putting out 9.5 BHP.

Now that its run in ,performance wise good acceleration and it feels that it will do 50MPH all day but on the dual carriageway top speed is about 55MPH with 60 MPH downhill if I'm lucky. Ive always felt that it will not rev high enough to reach a better top speed. Perhaps the front sprocket is the answer ? I was concerned that changing it would just slow it down !!

Ive got a TWE 175 kit on one of mine with same gearing as above.
behaves exactly the same. in fourth the throttle only acts as a volume control. I feel 16t front would be the way to go.

[Adam_Winstone]

Bin the 17 tooth front sprocket for a start! Considering that you're using the same carb as the GP200 and a pipe that is similar to the SIL Stg IV GP200 then you should be looking to use a similar final gear ratio. You don't say what your porting spec' is, which would have influence on the final ratio required, you should question whether you're kit is putting out more power than the larger GP200 and so able to pull longer gearing???

LI150 15/46 = 5.2:1 top ratio and GP200 18/47 also = 5.2:1 top gear ratio.... so where did the idea that it might pull a 17 tooth front sprocket come from?

At 4.6-4.7:1 (depending on what rear sprocket is fitted) you are trying to pull a top gear that is longer than was fitted to SX200, GP200 and SIL GP200 Stg. IV so I would expect your bike to ride perfectly well from 1st gear thru 3rd but then struggle to pull 4th correctly and making it pretty slow in top. Fit shorter gearing and you should find that the bike is faster throughout.

Best of luck.

Adam

PS - You may find that you can pull a 16 but you could well find that a porting tweaked 175 runs better if you revert back to the original 15 and the GP200 5.2 ratio.

[Hammer RB230]

So it looks like we need to change the front sprocket ! just a decision on what size 15 or 16 tooth !

I forgot to mention my kit has standard porting.

Cheers

[dickie]

So it looks like we need to change the front sprocket ! just a decision on what size 15 or 16 tooth !

I forgot to mention my kit has standard porting.

Cheers

15.

[Andie]

That's quite a lot of useful info, thank you

Bin the 17 tooth front sprocket for a start! Considering that you're using the same carb as the GP200 and a pipe that is similar to the SIL Stg IV GP200 then you should be looking to use a similar final gear ratio. You don't say what your porting spec' is, which would have influence on the final ratio required, you should question whether you're kit is putting out more power than the larger GP200 and so able to pull longer gearing???

LI150 15/46 = 5.2:1 top ratio and GP200 18/47 also = 5.2:1 top gear ratio.... so where did the idea that it might pull a 17 tooth front sprocket come from?.

The gearing is what was recommended by kit manufacturer ( '17T giving 4.99- 1 ratio' - with an 81 link chain; i have the original 125 gearing) the porting is 'lightly tuned' - its a 175 barrel with a meteor 3 ring piston (the Gori 175 kit).

[Rich Oswald]

Guys, there are a couple of posts on here which make comparisons to a LI 150 box, well simply you can't. This is a LI 125 box with a 17 tooth front sprocket. It's a lightly tuned 175 Gori kit which should go a lot quicker than it does. I rode to the York rally with Andie, the OP, and it is slow, very slow, would not go above 40mph. He has since had it dynoed at Chiselspeed with not much improvement. There is something wrong, maybe it is the gearing as the carburation should be ok after the dyno. Going down to a 16 front would give him 5.3:1, which as Adam says should be more than enough and definitely more than a st'd LI 150 or GP 200 @ 5.2:1

Rich'

[Warkton Tornado No.1]

Post by Rich Oswald » Mon Nov 14, 2016 3:56 pm

Guys, there are a couple of posts on here which make comparisons to a LI 150 box, well simply you can't. This is a LI 125 box with a 17 tooth front sprocket. It's a lightly tuned 175 Gori kit which should go a lot quicker than it does. I rode to the York rally with Andie, the OP, and it is slow, very slow, would not go above 40mph. He has since had it dynoed at Chiselspeed with not much improvement. There is something wrong, maybe it is the gearing as the carburation should be ok after the dyno. Going down to a 16 front would give him 5.3:1, which as Adam says should be more than enough and definitely more than a st'd LI 150 or GP 200 @ 5.2:1

Rich'

Thanks for the clarification, Rich. I was beginning to think it was me that was confused!

What would you expect from a Gori kit in that set up? A rhetorical question as I would have thought it should land you in @ least GP200 territory.

So, Andie. Rather than check on here, with respect, what do Chiselspeed say? What do the graphs say?

[Adam_Winstone]

Returning to the issue of state of tune and the fact that this is a Gori 175, rather than your average 175 kit (commonly little more than a 150 bored to 175cc), the ‘tuned’ nature of the Gori kit will not be wholly unlike the tuned nature of a SIL factory Stg. IV 200. As such, the increased port durations will produce good power but they will do so at a somewhat increased rev ceiling, which you will only benefit from if your motor can reach and stay in this higher rev band… drop out of the revs and you drop out of the power. Along with the revvier big bore clubman and 22mm carb, which are both intended to allow the motor to rev higher than the standard SIII exhaust and 20mm carb fitted to TV175 (and SX200 and TV200), SIL stuck with Innocenti’s GP200 gearing at 5.2:1. Indeed, even the official Lambretta tuning manual details increasing port durations, raising compression ratio and upping the jetting for an Innocenti GP200 but it makes no reference to changing the gearing, whereas if you look at the section on increasing output on an LI125 by changing to LI125 Special / GP125 specification it does say that you need to fit the shorter GP125 gearbox to allow it to rev higher/harder. If you don’t allow it to rev then you’ll end up with a bike that struggles to stay in the revs/power and you end up with a bike that is no faster or perhaps even slower (in 4th gear).

The same should apply to your bike/motor, which will be a similar porting spec’ to a SIL Stg. IV 200 but with a slightly smaller CC. If your porting is similar, your components are the same but you’re 25cc less then I wouldn’t expect your bike to be able to pull gearing that is longer than that of the GP200 IV (5.2:1). The 5.3:1 that LI125 16/46 (stretched 80 link or 81 and pull down tensioner) would result in seems to make sense for a 25cc smaller, but otherwise similar spec, motor.

Do please note that incorrect jetting could very easily be responsible for a loss of power too (that’s another discussion to be had).

Adam

[Warkton Tornado No.1]

Post by Adam_Winstone » Mon Nov 14, 2016 4:50 pm

Returning to the issue of state of tune and the fact that this is a Gori 175, rather than your average 175 kit (commonly little more than a 150 bored to 175cc), the ‘tuned’ nature of the Gori kit will not be wholly unlike the tuned nature of a SIL factory Stg. IV 200. As such, the increased port durations will produce good power but they will do so at a somewhat increased rev ceiling, which you will only benefit from if your motor can reach and stay in this higher rev band… drop out of the revs and you drop out of the power. Along with the revvier big bore clubman and 22mm carb, which are both intended to allow the motor to rev higher than the standard SIII exhaust and 20mm carb fitted to TV175 (and SX200 and TV200), SIL stuck with Innocenti’s GP200 gearing at 5.2:1. Indeed, even the official Lambretta tuning manual details increasing port durations, raising compression ratio and upping the jetting for an Innocenti GP200 but it makes no reference to changing the gearing, whereas if you look at the section on increasing output on an LI125 by changing to LI125 Special / GP125 specification it does say that you need to fit the shorter GP125 gearbox to allow it to rev higher/harder. If you don’t allow it to rev then you’ll end up with a bike that struggles to stay in the revs/power and you end up with a bike that is no faster or perhaps even slower (in 4th gear).

The same should apply to your bike/motor, which will be a similar porting spec’ to a SIL Stg. IV 200 but with a slightly smaller CC. If your porting is similar, your components are the same but you’re 25cc less then I wouldn’t expect your bike to be able to pull gearing that is longer than that of the GP200 IV (5.2:1). The 5.3:1 that LI125 16/46 (stretched 80 link or 81 and pull down tensioner) would result in seems to make sense for a 25cc smaller, but otherwise similar spec, motor.

Do please note that incorrect jetting could very easily be responsible for a loss of power too (that’s another discussion to be had).

Adam

Absolutely agreed, Adam

However, to be fair to Martin & all at Chiselspeed, aren't they best placed to comment as they have had this machine on their test bed? I feel sure that out of all of us, they should be able to offer the best solution simply by an analysis of what they've been paid to do, possibly with some reference to Gori themselves.

I think that is all that I was trying to advocate from Rich's comment

[Adam_Winstone]

^... agreed but many of us have experience of dyno requirements vs road requirements.... yet I don't aim that at Chiselspeed as I totally respect their work (and products).

Nor was I aiming my comment at you WT1 as we must have been typing at the same time and I'd not seen your response when I posted mine.

All good discussion to help

Adam

[Andie]

hello guys

thank you for the comments and advice. I should have worded the Original Post. better, I was curious as to the general ballpark as to what others get and didn't really want to get into names and components...

However the engine has been well built, with good components and I am happy with the service from all involved, Chiselspeed took care to tune it as well as they could given what I had fitted to it; i did all the final fitting myself and am learning as I go along... I was running far too lean as I have fitted a drilled box + fast flow air filter.

here's the dyno. red for now. I think the graphs look good.



I ran in after dyno.

I may just be riding it wrong I think I might redo the air intake system and jet accordingly over the winter and check everything.. Thanks again.

[Warkton Tornado No.1]

The power/torque figures are reasonable. No better than a good, standard GP150 IMHO, so for the expense incurred, I’d be curious as to what Gori have to say.

However, Chiselspeed’s graph would seem to indicate as far as the top end is concerned, you ought to be able to attain a ‘real life’ 60 mph & hold it.

Your right hand glove is not Teflon lined on the palm & fingers is it?

[Phil D]

Hi Andie
I think I mentioned to you before we have similar set ups .
The only real difference is I run with a 16 tooth front sprocket as mentioned .
I've not measured mine flat out but a few months ago I set the gps on my phone and I got 57.9 mph
I think it had a bit more left but as you say this set up is ideal for round town and the odd
Local rally .
If you want to go on long touring journeys I think your probably looking at a expensive rebuild or another engine .
It can start to get a bit expensive to say the least.
It all depends on what you want really but an li 125 will always be a bit limited As somebody recently told me there no substitute for cc's.
From what you said before you had it set up professionally I wondered what their take on it was ?

As I said we have similar set ups
I would say at least 57.9 mph is achievable
As you said you put good quality kit on- mine is like a mirror image of yours but with budget quality stuff .
Li125 gearbox,
22 mil jetex,
kba clubman,
Indian 12v.
150 cylinder bored out to 175
ports cleaned
stretched 81
46x16,
set up with plug chops and ears/ eyes.
Something just doesn't add up your scooter should fly!