Hp4 flywheel for px200?

hi i noticed i havnt got much torque on low and mid with my setup, btw set up is malossi kit, port case and 24 si carb, im assuming that hp4 flywheel will solve my problem…am i rigth??? please help. my top speed is 130kms…is this the correct topspeed for my setup?? btw im using a left hander sip jim lomas pipe. thanks a lot in advance for any suggestions and advices.

yes its cut and polished but not the fine heaved they call it. im also worried about the bearing’s reliability, maybe ill give it a go and update you on this, thanks so much mate. ride safe!

got it mate thanks thanks.

In theory, but you may also lose torque with the HP4 due to lack of inertia through less weight = less momentum. I have used the HP4 flywheel on a Malossi 210, it’s fun but it will f**k up your clutch pretty quickly unless you have it banded and strengthened. HP4 is OK for a quick blast, but I would not recommend it for everyday use at all.

If you have a 60mm crank I would suggest you install this instead of the HP4 flywheel. The extra stroke will give more torque. I am currently rebuliding my 210 engine with this set up.

You will either need to install a 1.5 mm head gasket or get your head remachined to accommodate the xtra stoke. There are better ways of doing this but as a quick fix it will work.

Don’t use a 1.5 mm base gasket, as this will move the usable power even further up the rev range giving you even less torque, making the malossi 210s general lack of torque even worse. As I said, pack it by 1.5 mm at the top of the barrel. if you really want to get a lightened flywheel, use the PK XL one that they sell on this site. This will give a slightly better pick up, but won’t destroy the rest of your engine like the HP4 has been known to. Enjoy

The piston travels 1.5mm further up and 1.5mm further down, equalling 3mm.  If you have the head which is already milled out for a 60mm crank, you shouldn’t need a packing plate.  If not, put it under the head.  Make sure you check the squish gap clearance, aim for about 1.2 mm minimum.

ok but should i put 1.5mm base gasket as well?

ditch the lomas pipe, forget the longstroke, fit the hp4 and simonini or pitone exhaust

[quote user=".DiscuS."]The HP4 won't really give you torque low down or mid (reduction of inertia since lighter weight), but it'll give you a good boost in hp through the whole power curve roughly 1 hp + You'll also notice the engine picks up a lot quicker (better acceleration). I hear say its a good combo with malossi, allows the kit to rev up where malossi create there hp.
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hp is a function of rpm and torque.. you could have a 15hp motor that had no torque but rev'd to 12k and you could have another 15hp motor that only rev'd to 7k but would have monster torque. so if you get an extra 1hp through to whole curve, that means you're getting more torque through the whole rev range.. hp4s are lighter which means less torque is required to accelerate them which means more torque is availiable to spin the back wheel, which means you accelerate faster... :) they're definately worth it if you want to go fast, but your lights might be a bit dimmer :)

thanks a lot d2c for the info. do you advice a mazzuchelli crank long stroke for my set up? i have one in my shelf but not sure if its worth installing it. please help.

thanks thanks so much for that info specially with the longstroke gasket, btw im using this head which i bought from sip im not sure if this is the one that you wont be needing the 1.5mm gasket on the head, what if this is the case? where now should i put the 1.5mm gasket…head or base? last question…px200 stroke is 57mm right…mazz longstorke has 60mm, how come were just placing 1.5mm gasket were there is 3mm difference? thanks thanks.

ok thanks mate, i think ill give it a go and update you on this, ride safe.

[quote user=„ozzy1000“]

[quote user=".DiscuS."]The HP4 won’t really give you torque low down or mid (reduction of inertia since lighter weight), but it’ll give you a good boost in hp through the whole power curve roughly 1 hp + You’ll also notice the engine picks up a lot quicker (better acceleration). I hear say its a good combo with malossi, allows the kit to rev up where malossi create there hp.
[/quote]

hp is a function of rpm and torque.. you could have a 15hp motor that had no torque but rev'd to 12k and you could have another 15hp motor that only rev'd to 7k but would have monster torque. so if you get an extra 1hp through to whole curve, that means you're getting more torque through the whole rev range.. hp4s are lighter which means less torque is required to accelerate them which means more torque is availiable to spin the back wheel, which means you accelerate faster... :) they're definately worth it if you want to go fast, but your lights might be a bit dimmer :)

[/quote]

Yep, my mistake... there is increase in torque thourgh the power curve as well.

Thank you for correcting me ozzy

got it and thanks so much, ride safe.

[quote user=„dlegendslayer“]thanks a lot d2c for the info. do you advice a mazzuchelli crank long stroke for my set up? i have one in my shelf but not sure if its worth installing it. please help.[/quote]

I havent had any experience with a mazzchelli long storke crank, is your one the cut and polished one? If so I’m presume they are a little lighter then stock one’s, the ‚cut‘ bit of the crank will allow more fuel/air mixture to pass through in the end giving you more power. But i think to get full potential from the mazzuchelli crank and cylinder kit your probably going to have to change the carb to a bigger one .

Correct me if I’m wrong anyone about the crankshaft.

Hope that helps

Yep, definitely give it a go. You probably want to replace bearings though when you fit new crankshaft to be on the safe side.

The HP4 won’t really give you torque low down or mid (reduction of inertia since lighter weight), but it’ll give you a good boost in hp through the whole power curve roughly 1 hp + You’ll also notice the engine picks up a lot quicker (better acceleration). I hear say its a good combo with malossi, allows the kit to rev up where malossi create there hp.



No, not if you have the head which is machined out for the 60mm crank.  The extra room in the head alrady compensates for the extra length.

got it thanks.