Yikes, another jetting question...Too large of a main and pilot jet will cause what?

[k00leo]

Thats right.... another jetting question... :lol:



Ok,

I threw the stock carburetor back on my 350x.
Stock pilot, stock needle, stock main.
Un-oiled UNI, with airbox lid on.
Clip in lowest position (rich)

I did a plug chop and it seemed like it was running lean. Spark plug was slightly gray and it would backfire/lean pop on decel.

I think this is the case because of the weather, right? Dense air makes machines run lean.

It's around 20-50 degrees outside this month. 85ft above sea level.

So i've learned that when jetting, purposely jet rich and go down from there. I threw in a 158 main jet and 45 pilot jet and it would basically feel like it was bogging a little throughout 1/4- 3/4 and would completely cut out near WOT.

The bogging throughout 1/3-3/4 should be because my clip is too rich, correct? I need to go up a clip position or two.

the WOT cut off is happening because my main jet it way too big, right? I did a plug chop and the spark plug was basically dead black. After that chop, the bike wouldn't kick back over. I'm guessing i fouled that plug, right? I put in a fresh plug and it kicked back over after a few kicks.

After a few kicks i mean like 20. Am i flooding the bike because the pilot is too big? I did not pump the throttle at all before i tried to kick the bike back over. The bike would start easily with the 42 pilot, but it would lean pop with the stock main jet.




I'm thinking about putting the clip in the second lowest position (rich), putting the 42 pilot back in and putting a 145 main in. What do you think? I would prefer to run the bike with the air box lid on btw. Of course i need to try this later tonight.... just telling you what i am thinking.

[beets442]

You might have to kick it a little more in cold conditions to get it started but should run the same.From 145 to 158 is a big jump.What position do you start your choke at? Yes, back to stock.

[k00leo]

Well yesterday was the first time i have ever had the 350x carburetor on the 350x. previously, i have a 400ex carburetor on it (i want to go back to stock).

When i started it yesterday with the 350x carburetor, 138 main(stock), 42 pilot (stock), choke all the way on, it started in like 2 kicks, no problem. Plug chop showed it was running lean at WOT and would backfire on decel.

Now that i have changed everything, 158 main, 45 pilot, clip all the way down, its hard to start. The Pilot jet should control the starting right? (as well as the air/fuel screw) Is the pilot ... i dont know... flooding the bike?

Bah... i just need to tinker with it.

:)

[200XMichigan]

I would got back to the factory jets on the 350X carb, check to make sure they are real clean set it all exactly to factory unless anything is modded on the trike. If everything is good on the trike a 4 stroke Honda doesn't really want to be re-jetted for the cold.

[k00leo]

Well i went back to the factory jets.... 138 main 42 pilot and middle needle position

man o man.. boy did it backfire / lean pop.

I didnt even bother to do a plug chop. i rode it around for 5 min after it warmed up and i cut it off.

I then put a 45 pilot in there.... fooled with it for like 45 min and couldnt get it started again :-/

i think tomorrow i'm going to try to put the 42 pilot back in and drop the clip maybe 2 spaces. (rich it up a little). what do you guys think?

If that gets rid of the lean pop, then i think i will put a 145 pilot in there.




Maybe i have a air leak? I really dont think so... what do you guys spray around the possible air leaks to see if the RPM jumps up? starter fluid? i have no idea.

[200XMichigan]

Honestly on a stock 4-stroke trike I have never needed to re-jet. Is it possible one of the factory jets is partially clogged? Does it have an after market exhaust or removed the air box lid? Did you set everything to factory, needle clip postion, air mixture screw?

[k00leo]

i dont think any of the jets are clogged. They are brand new. I know my gas is clean, i just put in a new peacock with filter.

I did add a fuel stabilizer.... though i kind of doubt that is affecting it.


No aftermarket muffler, stock airbox with lid.


The guy i bought it from said that the previous owner must have done something to the engine because it has some hop to it. I dont really beleive him though. Maybe a bore a new piston?


hmmm... i just re-read the manual... it says that i should be only one turn out from fully seated. I think i was at 1 1/2 - 2 1/2. Even if i was rich on my air/fuel screw... backfiring is a symptom of lean jetting, right?

[200XMichigan]

Too much fuel stabilizer makes my Honda Nighthawk run like a b1tch. Put some fresh 91 octane, factory jets and factory specs and a fresh plug. Depending on what brand of stabilizer I have had to drain it out and run fresh gas. Best I have found is genuine Stabil but even that makes it run slightly different.

Try running it with the choke on, if you are lean it will run good with the choke on. I would suspect and air leak or a problem with the tuning before re-jetting a 4 stroke.

[k00leo]

Hah... too much fuel stabilizer huh? Well... that may actually be the case.... i didn't measure, i just poured a little in.... The bottle did say too much would not hurt.

Anyway, i will put the stock jets back in, put fresh gas in, new sparkplug, adjust the air/fuel screw according to the book and i will see where it gets me.

Thanks 200xmichigan. I will report back tomorrow.

[camoweasel]

What is your fuel screw set at? It could possibly be plugged or buggered up. Take it out and clean to make sure its clean. I would leave the stock pilot and try uping the main a little and see what happens. If your running the factory exhaust, I can't imagine the factory jetting being that far off??