what jet would you guys recommend?

[Strigoi]

i'm going to be putting my motor together in about a week and a half (first chance i'll have time at work) and was wondering where i should start with the jetting. i'm not sure what it was running before, but it ran well with the 22mm Mikuni and header/silencer on it. i'm guessing that it will need to be changed since i'm doing a cam and piston.

i've got one or two spare jets, so i'd like to be able to get it running right quick. me and a friend might try to make it down to the mini moto (5+ hour drive) so i want it running decently. i won't have much time to do any testing with it.

the mods are in my sig.

 

[npatton19]

I'd say around a 125-130 main jet. Theres really no universal jet or carb setup, the only way to determine what size jet or pilot you need is by testing. The cam and piston shouldnt really change your jetting, if anything you will need to mess around with different pilot jets, testing different pilots will give you nice smooth acceleration. Your main jet is mostly being used at 3/4 throttle to WOT, as long as your mixture is still coming in and going out the same method(intake system/exhaust) your main jet should be ok. Carb tuning is a lengthy process unless you have dealt with the carb and engine combo before and know what it needs, if your lucky you will get it bang on first try but most people dont have that much luck.

I also noticed you are planning on running 18pd springs with the dyno .265 and 1.2 rockers, unfortunately this setup wont work because your springs will bind(spring coils touch each other). Your either going to want to ditch the 1.2 rockers or get yourself 26pd springs which wont bind and some chromoly pushrods, that valvetrain and 26 pd springs wont last long with stock pushrods. I understand you want to get your motor/bike up and running as soon as possible but be patient, take your time and do it right the first time so you dont have to learn from your mistakes and you can learn from others peoples mistakes.:thumbsup:

 

[Strigoi]

I also noticed you are planning on running 18pd springs with the dyno .265 and 1.2 rockers, unfortunately this setup wont work because your springs will bind(spring coils touch each other).

i contacted AGK about that they said i shouldn't have any problem with coil bind with that setup. i planned on checking that when putting everything together so having to swap out the rockers is no big deal if it binds. if it does bind, i'll just go ahead and pick up the 26lb springs (or a big cam and big valve head).

i'm looking to get it together quick, but i'm not going to half ass it. all the tolerances and shit will be checked. i work at a Harley dealership so i've got plenty of mechanics that know what they're doing to help me out if i have problems.

all the techs love mini bikes and get excited when we bring them in with new stuff to put on. :laugh:

 

[npatton19]

Just remember salesmen always want your money, im not saying AGK is selling you but I've been told many times by many sources at 4cycle.com that 18pd springs will not work with a dyno cam and 1.2 rockers but by all means try it out.

There are two different 18 pd springs, one type from the old Honda G200 flathead motor and another specialized spring with thicker coils to last longer. Im not sure which ones AGK has because ive never bought their 18pd springs.

If you look on NR-racing.com it says under the 18pd springs that coil bind comes at .280 lift, the rockers will add at least 0.050 lift so add that to the cam and your wayyy over. Im not going to tell you what to do but you might want to do a little bit of research.

Your also going to need a Honda pushrod guide plate because the clone ones dont have enough clearence for that much lift.

 

[Strigoi]

i know what you mean about them wanting to sell stuff. the 18lb springs i have are Honda ones and they're from AGK.

i just checked NR and you're right about the guide plate for the rockers. i remember reading that but couldn't remember where when i went to order stuff. i checked a few sites (not theirs, dammit) and decided to just go ahead and get them since it didn't really cost any more for shipping.

i might go ahead and order the guide plate and some CM push rods tomorrow though. i need a crank bearing which NR has so i might as well just get all of it.

if i get that stuff, i'll just wait to install the rockers until i do a different cam and get some new springs.

thanks for the help.