Day spent on MB Dyno

[tony]

Hi mate.. good effort on behalf of Mark to try and satisfy your needs. But to me it looks like you may have lost a little more than gained. Then its hard to see the scales on the graphs. Did you use the same pipe here? I would be guessing Mark reworked the pipe to work with the port modifications to get the best out of this tune?

[lifes a drag]

im with tony here , areyou sure u got what u wanted ,,

to be honnest theres a lot of TS1 owners that would die for what u had before tinkering with owt ,,

i hope your happy with what u got but to be honnest it looks like its gonna be more involving to drive " if ya know what i mean "

hope u have fun anyway

[Mag]

All work was with the one pipe, the stainless rev tour that seems to be one of only a few survivors. We looked at loads of graphs with similar engines and different exhausts but all suggested a retrograde step exept the JL4. It looked like I would gain even more peak HP with the JL but move all the power further up the range.
Mark knows my bike and how I ride and tuned to match. My gp is lightweight and I never carry a passenger. I do like to push my bike and had become frustrated on motorways when sat over 70 that the grunt could tail off just when I needed it.
I built my gp as a compromise between thrash and reliability and it has been very reliable so decided to up the thrashability.

[Adspeed]

I do like to push my bike and had become frustrated on motorways when sat over 70 that the grunt could tail off just when I needed it.

One solution to this may have been to run a bigger front sprocket....

According to Scooterhelp you'd have needed to do about 7000 to do 72mph running a final ratio of 4.84. This would take you well into the power band with very little left as you say.

Changing the front sprocket to a 20 would take it to 4.6 and running 72mph at around 6400. This would give you plenty power left to wind it back to go to say 80+ without losing the low mid torque.

Apologies if I have the Indian ratios wrong.

I'm running 4.51 and doing 70mph at 6300 which is perfectly just as my power band starts.



Mag, was the engine dynoed in a jig or a donar bike just out of interest?

[Mag]

I did run a 20 tooth for a while. It sapped a bit of fun and I got sick of climbing slight inclines in 3rd faster than 4th could manage.

[Adspeed]

Well lets hope this new set up satifies you requirements.

Keep us informed!!

[goldeneye]

MAG probly failed to mention that his GP is full carbon fibre bodywork, that probly saves a few pounds (unlike the rider!), and he does "give it the full beans", if he wanted to be sensible (and he isnt, believe me!) his yellow italian proper stage four is lovely, and pulls like a train. he"s gradually evolved his engine over about the last 6-7 years, and has always improved it , and has always used broady to do it. like someone said , "i bet that was expensive", but paul (mag) likes the best for his scoots, and knowing him for as long as i have , he wont compromise . he says he"s not an engineer, but he really knows his lammys, and what he wants from them. as long as it"s a GP! :lol

[Killkenny]

I talked with Mark about Mags engine, Mags wanted a little bit more on
the top end. Mark had previously followed Mags in the car and already
knew where Mags motor worked and how he drives. Mark explained to get
the top end the bottom would suffer, but the little loss on bottom end
was well worth the gain at the speeds Mag wants to travel. Theres
loads left in the engine to play with, but at the end of the day its a
reliable road bike. And didn't Mags win the LCGB coast to coast this
year? I believe thats 6 years in a row MB Developments engines/tuning
has been the first Lambretta to finish the race! That proves MrBee
knows what hes doing on road engines!

[Mag]

Nice one Mag.

When they dynoed ya engine did they do it in a donar bike or a JIG like JB Tuning doo sometimes?

They can do bike or jig. Think the jig is easier because you can strip the top end without even removing the suspension. The verticle bars at the back are to add substantial weights to simulate driver, luggage etc. Clever stuff to a dumbkopf like me.

[Mag]

Finally got my engine back in and got to try it on the road.
The issue I was trying to rectify was when travelling at speed that I didn't always have the power to overtake. You know when your sat at 70/75mph on a motorway and you need to nip past someone but you pull out and nowt happens an you just sit there waiting for the road to level off or go into incline so you don't look like a twonk and have to pull back in.
Well today I acheived a comfortable 73mph on the A19 while overtaking a car. What was nicer was then shifting out of third and powering past at a gps'd 83 mph in forth.
Where my high speed power used to be on the edge it is now exactly where I need it.
What about low down driveability I here you ask? Well round town it is at worst as tractable as my standard Italian GP. It ran happily street to street in fourth at 30mph. In fact I tried tootling along at less than 1400rpm in fourth and then accelerating and found that it was more than happy. Up to about 4.5k it was strong ang steady and then it took off like a scadded cat!
So what have I got? A very tractable motor about town, a country road screamer and a high speed motorway cruiser. Am I happy? What do you think?!