210 Malossi Worb 5 gearing

[Jack221]

Looks like a good test. Results are better than I was expecting from what you were saying. With those port timings it wasnt going to rev much higher in top and I am surprised it goes that well. With your gearing 8000rpm calculates to 79mph. Which is very respectable. I think there is still more in it, at least another 500 rpm in top.
I suggest you need to get your transfer timing duration up (quite a lot more) for more rpm and more power at the top end. As already said, the easiest way without any major port work is a 60mm crank. I calculate you need a 0.8mm base packer and a thick head gasket to get your squish back.
With a 60mm yours might be quicker than mine

[Jack221]

btw, Mine has a JL RZ rhs on too and have no plans to change it, ever!

[Noplastic]

i was just thinking instead that a revvier pipe could do the trick... i contacted pipe design and planning to get one of theirs theres one that starts 450 rpms later and revs 1000 rpms higher!

[Jack221]

I think you will be wasting your money. It is already going better than I would expect with that port timing. A fancy pipe is not going to improve it enough and the JL RZ you have is already one of the best there is. A fancy pipe will just move the power you have up the rev range. It could even feel slower on the road with a high rpm pipe as you would have to thrash it everywhere.
And a new crank is cheaper with sure, proven results

[Noplastic]

I think you will be wasting your money. It is already going better than I would expect with that port timing. A fancy pipe is not going to improve it enough and the JL RZ you have is already one of the best there is. A fancy pipe will just move the power you have up the rev range. It could even feel slower on the road with a high rpm pipe as you would have to thrash it everywhere.
And a new crank is cheaper with sure, proven results

Hi! with what exhaust port timing in stroke 60 you reach 8.500/8.800rpms in third? What flywheel you use? Cause at 190 degrees i reach 8000rpms in 3rd (66mph) with 190degrees exhaust port with longstroke 60 jl and elestart flywheel 2,2kg. Is there something that im missing here?

Edit: it's a bit more 8000: 8250 approx.

[Jack221]

How many degrees on the main transfers with the 60mm crank? Which of your barrels you have on? And what thickness base packer?
The degrees on the exhaust dont matter so much but the transfers must be right.

You should really get a lighter flywheel. The heavy ones on a revvy engine can shear the woodruff key. I Have a 1.7kg modified PK one. Seems to be a good compromise for a road scooter.

[Noplastic]

How many degrees on the main transfers with the 60mm crank? Which of your barrels you have on? And what thickness base packer?
The degrees on the exhaust dont matter so much but the transfers must be right.

You should really get a lighter flywheel. The heavy ones on a revvy engine can shear the woodruff key. I Have a 1.7kg modified PK one. Seems to be a good compromise for a road scooter.

Hi thanks for the reply, as i said I fitted a longstroke crank and kept the JL. 190degrees exhaust port, standard base gasket and 1,5 head gasket, squish approx 1,5mm. Dynoed the bike yesterday: 25,9 hp at 7.500 rpms with top speed of 107kmh (66mph) in third gear. Now looking at the gear calculator with the 23/65 z37 (it is actually a z36 with drt xmas tree with 19 teeth 3rd and 20 teeth 4th,i'm not sure about the exact ratio) it says that 66mph corresponds to approx 8200 rpms.... I tryed to raise the barrel with a 0,5mm base gasket but the result is an annoying gap of power at very lower revs in every gear. I'm using the Mhr, the transfers are 130 degrees.

[Jack221]

JL is good, MHR good, 60mm crank good but Something is wrong here. A standard base gasket, 1.5mm head gasket, on std MHR barrel with a 60mm crank is 180ex and 124tfr. How are you working out your durations?

Do you have locating lugs to keep your head centred?

You are coming close to the whole tuning problem How to make it rev and pull. Not easy but there are ways

[Noplastic]

Something is wrong here. A standard base gasket, 1.5mm head gasket, on std MHR barrel with a 60mm crank is 180ex and 124tfr. How are you working out your durations?

Do you have locating lugs to keep your head centred?

You are coming close to the whole tuning problem How to make it rev and pull. Not easy but there are ways

I fit a piece of wire as marker to a flywheel cover nut and set it to zero right the moment before that the port starts opening. Then i turn the flywheel anticlockwise until the piston reaches the bottom dead center and back to the top up to when the port is fully closed again. I dont know why the measurements on my engine block are different from those taken by scooter center... I only trust my measurements cause they've been taken on my engine block not on "any" engine block. if anyone could tell me how much they packed their Malossi barrel with a jl pipe would make me a big favour. @Santacama: you said you have 190/130 on your MHR...let me know!
@worb225: how about your settings?

As i said before i packed under the head 1.5mm , i know is a torquey set up but if i raise the barrel it doesnt pull lower down, its maybe good on the dyno but it doesn feel good on the road. It revs alittle higher than with stroke 57 not as higher as i expetected... I am not complaining, i am very satisfied, this bike has huge power, wheelies and pulls like a train and reaches 8250rpms in third with a heavy flywheel so it can be improved a lot... i just wanna make sure that i am fully exploiting its potential. If you know what i mean..

[Jack221]

That explains it. A port is open when the piston edge is level with the port roof. Not when you can see light through the gap. Very small changes have a big effect on the degrees.

According to my opinion and software you need 0.8mm packer on the base. And fit a head gasket to set the squish to 1.2mm (I often use 1.0mm squish on my own scooters). Once you have done this you can work on the other possible issues to get the torque up.