|
|
Post by tsimi on Mar 23, 2018 18:40:16 GMT -5
0.45 or .50 squish! That is very tight isn't it? Can i measure that with a .8mm solder or should i get a smaller solder?
What should be the ignition setting on the MVT DD19?
The pipe is super sexy and she has a super fat belly. I mean like pregnant fat belly. Should sound awesome.
Too bad Roost isn't doing a better marketing job on their havoc cylinders.
Their website doesn't even mention the cylinders. Nor does their facebook page which was last updated somewhere last year.
|
|
|
|
Post by ryan_ott on Mar 23, 2018 18:46:09 GMT -5
If going that tight your going to need some race fuel! .60-.65 may be better for street use. I think the MVT gets set at .35mm BTDC. I’ll check on that.
|
|
|
|
Post by tsimi on Mar 23, 2018 18:50:02 GMT -5
Thanks Ryan.
What jetting is recommended to start with on a 28mm PWK with UNI filter?
PJ 50
MJ 140
|
|
|
|
Post by ryan_ott on Mar 23, 2018 19:03:05 GMT -5
I would add 5 to each 55/145 It may be too rich for your area but better safe. Do keep the pilot and needle rich. The high HP motors are more on/off throttle. For city driving you’ll be doing lots of coasting unless you want speeding tickets daily. The rich bottomend keeps you cool when the throttle is closed. Remember this: 49ccscoot.proboards.com/thread/18522/iggy-installation-help |
|
|
|
Post by ryan_ott on Mar 23, 2018 19:06:15 GMT -5
Are you going to be running an egt gauge or just monitor coolant temp?
|
|
|
|
Post by 190mech on Mar 23, 2018 19:17:26 GMT -5
The race world recommends 1% of stroke for squish,that'd be .4mm..Only for super quality bearings and components..Ideal (theoretical) squish should be 0 as we dont want any mixture at the piston edge during combustion(causes detonation),the combustion chamber bowl determines the compression ratio,not the squish gap..The 1% is for mechanical slop and stretch at high revs,the chamber bowl with your kit looks a bit dated..The ideal design is the RSA125 which Frits Overmars posted elsewhere;  I would set the Roost kit up exactly to their spec!! |
|
|
|
Post by tsimi on Mar 23, 2018 19:57:36 GMT -5
Are you going to be running an egt gauge or just monitor coolant temp? Nope, no EGT for now. I do want to use coolant temps, in and out, and CHT temp. |
|
|
|
Post by PIG on Mar 23, 2018 20:08:12 GMT -5
I set my MVT at 0.12mm BTDC then make small adjustments either advancing or retarding the timing till I’m happy with my plug readings. I had heat issues running 0.35mm BTDC, just couldn’t get it right. Maybe it was me, I’m not the greatest with these iggies. As for the carb, Ryan is 100% right. Set your pilot and needle as rich as you can get away with. You’ll burn that cylinder down city riding if you don’t. Set the main jet spot on like normal. Remember like an 1/8 of the throttle and you’ll be going like 40+ MPH, your always on the pilot and needle circuit around town. A short burst of WOT and your doubling the speed limit, gotta find some open space to give her onion. Lol.
|
|
|
|
Post by tsimi on Mar 23, 2018 20:28:12 GMT -5
Thanks for all the info guys.
I just take it one step at the time and try to work careful and precise.
If anything should arise I'll ask again.
I also try to take as many pics as possible as I go ahead with the install.
|
|
|
|
Post by 'O'Verse on Mar 23, 2018 21:11:52 GMT -5
What's the opening measure on your exhaust? Looks like about 36mm in the pic.
|
|
|
|
Post by tsimi on Mar 23, 2018 21:21:41 GMT -5
What's the opening measure on your exhaust? Looks like about 36mm in the pic. Haven't checked yet. I am at the vet right now but i'll check as soon i get back home. |
|
|
|
Post by tsimi on Mar 23, 2018 23:55:42 GMT -5
|
|
|
|
Post by tsimi on Mar 24, 2018 0:22:56 GMT -5
Can someone tell me what this screw/bolt is for?  |
|
|
|
Post by 'O'Verse on Mar 24, 2018 0:41:35 GMT -5
Looks like a passage screw/plug. In line with your water inlet. Hard to say. But best guess is the Roost is designed with a water cooled exhaust port. And for unequipped cases they just cap it off. I bet the flanged design is sold without the plug.  |
|
|
|
Post by 'O'Verse on Mar 24, 2018 0:47:41 GMT -5
30mm... Daaannng! A 28mm carb should rock that perfectly. I can stare at calipers on a brand new cylinder all day  . |
|
.