[/img]another bike build request
Moderators: Dan J, Diesel Dave, Crazymanneil, Stuart
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roverthetop
- I luv the smell of Diesel...
- Posts: 94
- Joined: Thu May 17, 2007 3:37 am
- Location: portland, oregon, us
another bike build request
so my mate loves my diesel bike. now he wants one. he runs a twin tank system in his truck and wants to do the same on his bike, so... biodiesel on one side and veg on the other. she started as a kwaker, some LTD, belt driven bastard. so, frame hack and mods, punsun engine, and yes, as he's never ridden a bike, he wants an auto, so we have a comet cvt in place. i figure a "fat bob" style twin tank system with all the switching valves and whatnot hidden beneath/ between. we'll see. 20hp should get him around with pennies in his pockets. heres a taste...
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Is that a Comet Duster your using?
If so I would recommend pulling the cover from the clutch and fitting a full set of bob weights (9 in total) and checking you have the lightest spring fitted (pink). This brings the engagement down from around 2200rpm to around 1600rpm which eliminates belt slip and produces a nice positive engagement early.
The engagement rpm can be bought down even more by filling the holes in the weights with lead but remember the punsun likes a few revs to start and its nice to be able to do this without engagement.
Other tips with this set up are to pinch the belt top to bottom and ensure you have around 5mm gap at the front. Any less and the belt will drag and much more and it will ride up the clutch before engaging and or fail to engage the top ratio on the driven unit. Obviously an adjustable set up is ideal however comet supply a variety of belt lenghts for different nominal distances between shaft centres so a perfect belt lenght can usually be found.
Also it wasnt initially clear to me but if you fail to engage the highest ratio on the driven unit, the large spring has some adjustability by pulling it and remounting it at different tensions, worth playing with before considering changing the spring.
Im still in the process of calibrating mine to my liking but am still managing to cruise at around 75mph, i reckon that theres possibly another 10mph to find.
The punsun has a particular sweet spot ( vibration wise) just under max rpm and I'd like overdrive to kick in shortly before this.
Hope this helps.
Mark
If so I would recommend pulling the cover from the clutch and fitting a full set of bob weights (9 in total) and checking you have the lightest spring fitted (pink). This brings the engagement down from around 2200rpm to around 1600rpm which eliminates belt slip and produces a nice positive engagement early.
The engagement rpm can be bought down even more by filling the holes in the weights with lead but remember the punsun likes a few revs to start and its nice to be able to do this without engagement.
Other tips with this set up are to pinch the belt top to bottom and ensure you have around 5mm gap at the front. Any less and the belt will drag and much more and it will ride up the clutch before engaging and or fail to engage the top ratio on the driven unit. Obviously an adjustable set up is ideal however comet supply a variety of belt lenghts for different nominal distances between shaft centres so a perfect belt lenght can usually be found.
Also it wasnt initially clear to me but if you fail to engage the highest ratio on the driven unit, the large spring has some adjustability by pulling it and remounting it at different tensions, worth playing with before considering changing the spring.
Im still in the process of calibrating mine to my liking but am still managing to cruise at around 75mph, i reckon that theres possibly another 10mph to find.
The punsun has a particular sweet spot ( vibration wise) just under max rpm and I'd like overdrive to kick in shortly before this.
Hope this helps.
Mark
-
roverthetop
- I luv the smell of Diesel...
- Posts: 94
- Joined: Thu May 17, 2007 3:37 am
- Location: portland, oregon, us