Question For The 300r Fooler Guys

[iamschme]

ok guys i need some 300r experience here.

83 300r
recently redid top end.
76.4 mm piston, some port work.
stock carb

the carb worked great when it was a 250 but once i put the 300 on it it seems to be lagging. i broke it in on 20:1 and it did ok but a little lean. then i went back to 32:1. no matter where i put the needle it bogs. no clean take off from idle to mid to WOT. but it does start up like a champ. i went from 130 to 145 on the main and it is still a little lean.

do i need a new bigger carb or can i jet the stock size to work?
if i can rejet--any ideas on where it should be set--just close will help as jetting on the internet is very difficult.

i've been tinkering with it for a couple of weeks and i just can't get it. HELP!!!

[Billy Golightly]

Need good clear close up pics of the spark plug.

[iamschme]

i'l have to get a pic but for now i can say that after a few runs on it the porcelain is medium brown but the metal band it dark at the back and grey at the tip. it has never gotten black at all. even after running it several times on the same plug, it just gets brown on the porcelain and a little grey on the metal.

[deathman53]

maybe a richer needle, richer pilot jet. your needle and pilot jet control the fuel 1/8-1/2 throttle, also the air screw could have an effect too, thats a factor for 1/8-1/2 throttle.

[hoser]

Install a main jet big enough to make the engine blubber when you run it WOT, then start going smaller on the jet size until it cleans out, actually your suppose to jet from bottom to top, give this a read http://12.227.214.171/BillGivensjetting.htm

Kinda long but worth the read.

[Dirtcrasher]

Install a main jet big enough to make the engine blubber when you run it WOT, then start going smaller on the jet size until it cleans out, actually your suppose to jet from bottom to top, give this a read http://12.227.214.171/BillGivensjetting.htm

Kinda long but worth the read.


THAT is one of the BEST jetting reads I've seen :beer

Thanks!!

[Bigbore]

I think I remember the main jet suppled with the Hondaline kit was a 165. Start there then work down.

[200xman]

The original Hondaline instructions call for a 135 main with the 300kit and a stock 83-84 carb.

[350x'inNY]

Most people don't keep the stock carb. Common upgrade is to go to the 85-86 carb or some aftermarket. My 300R motor came with a 85R carb on it. Finally getting around to finallizing the machine and firing it up in the next couple months.

Bruce

[iamschme]

i was trying to weigh out the options on tuning what i have vs buying a new carb. obviously jets are less expensive but would a bigger carb make a huge difference over the power of the stock carb? if so, then i don't mind getting a new one. the other question is what carb? i've heard 85-86 stock carb, 38mm pwk, 39mm pwk. and, will i need new intakes??? any help is appreciated.