450 carb

[monkeyballs]

Yes I know.. I should look threw the hundreds of pages of..... But trust me I tryed.

I just instaled a 450carb. I blocked off the hot start with a peice of ruber then 2 make sure it was sealed I put some gasket maker on top of that.

I have a 50 pilot, 185 main and 4th clip down. I sanded out the boot between the carb and the engine so it would fit with ez..

When I started it up today, it was runnning way 2 lean on idol when I gave it gas and let off it backfierd, so I decided to unscrew the pilot screw even more.. almost 4 turns. (yes I know its close 2 falling out..)

So that stoped the backfiering.. But now it sounds like it has an air leak some where... If I let it sit it will idol for a little then shut off. If I give it a quick shot of gas it will rev up then stay at high rpm for idol.. Then slowly go down. And it idols rough.. Like randomly uh, I guess coughts..

If most ppl were not running stock pilot jets I would say its running lean.. But since ppl do and im running a 50 I think there is something worng...

My build is,
-416cc
-11:1 comp
-hc stg 1
-Miled p&p
-full system yosh pipe no spark arrestor
-k&n air filter w/ no air box lid
-crf 450r timing chain

I was reading thew some of the posts and one of them said to not sand the air boot between the carb and the engine since it might leak air.. But I lightly sanded it, realy tightened the clamp when I mounted it, and it was still a realy tight fit.. So I doubte thats the problem. Then the hot start issue.. The way I did it I cant see how it could be leaking.. I understand that it might induce a boog since its not blocked off at the bottom of the hot start hole and there is 3 cc's or so of air....

Holy crud.. What a long post..
All this to ask, what could be worng? Whos had issues similar 2 this and what was the problem?

THANKS :D

[Wheelie]

Buy the correct hot start plunger before you try and tune any further.

It seems that the people that have the issues with these carbs are the one who don't correctly block off the hot start.

Buy the correct plunger from Honda, install it and report back.

[monkeyballs]

Thanks, I actualy ordered one about 20 min ago. I did a crap tone of reading and kinda got the hint that hot start is the way 2 go. :D. Should be in on wednesday with a 160-165-170 mj. Ill be good 2 go!

Just one thing I dont understand is where its drawing its air from. Since I only saw one hole at the bottom of the hot start. So I figured it was getting its air from the top.... But I guess not..

Any who thanks.

[tri5ron]

Originally posted by Wheelie
Buy the correct hot start plunger before you try and tune any further.

It seems that the people that have the issues with these carbs are the one who don't correctly block off the hot start.

Buy the correct plunger from Honda, install it and report back.
X2,
I learned this same lesson, just today, with mine.

you MUST use the plunger, to plug the hot start circurt at the BOTTOM.

Plugging the top of the hotstart port, with a piece of rubber will not work.

I had exactally the same symptoms you described.
Rremoved rubber plug, installed plunger, problem solved.

[Ryanwolfe911]

Question, why does no one ever install the hotstart and make it functional? Seems like that would be beneficial.

[monkeyballs]

$$

[sab24711]

i can see the hot start for kick start 400ex but for the e-start its kinda useless. i just put a 55 pilot and a 185 main i still need to tweak the needle its an hrc clip on mid. i live in a valley so its from 0 to 1000 or more in elevation. idk if this helps or not