2002 366CC fresh install tuning questions

[cmburnstx]

Hey all, let me run down the bike first so you have an idea of what it has and whatnot.

2002 Yamaha Warrior 350

JE 10.5:1 366cc kit- 20 minutes on rebuild and install
Stg 1 Hot Cam- 20 minutes on rebuild and install
150 Main
Needle on 2nd Clip
Stock Pilot
Alba Pipe
FMF Powerbomb
Snorkled intake w/ no box (I do alot of water crossing, there is a filter on the end)
20" Tires
Stock Gearing
91 Octane+Octane Booster
Castrol 4T 10W-40
Parking brake mod/blockoff
Pen Spring in Pump (didn't use valve cap because when I did the throttle wouldn't close all the way anymore)

Also some other unrelated stuff like widened and lowered front and rear, lighting, etc etc.

I ride at 0' of elevation. Sometimes -2' or so.

I installed the kit/cam, pulled the choke, and it fired right up. Loaded into my truck and drove it out to the open area to break it in. What I'm getting is a total bog down of power, like its out of gas. Put it back in first, sometimes fires right up, sometimes takes a few turns. As I'm going if I open the throttle up, its hit or miss if it pulls the powerband smooth.

I had to turn the screw out a bunch to make it go close to open throttle without bogging, but this in turn cause a very high idle.


Any ideas? Any more info needed, feel free to ask. And thanks in advance. :tup:

 

[YAMAHAULER]

what does the plug look like?

 

[alex456123]

If your running a stock pilot you need to up that a couple sizes... Like hauler said what does the plug look like?

 

[1statv]

Pic of snorkel please

 

[lbjamm]

Put needle on third clip and try it.

 

[jasonp]

sounds like maybe a air leak between the head and carb?

 

[cmburnstx]

Dark tan/brown. I'll snap a pic once I get home. Intake manifold and O ring are new.

 

[cmburnstx]

I'll move the needle and check it out.

Oh and can anyone tell me the part # through Dennis Kirk for the pilot? I bought a #35 from Yamaha but it was incorrect

 

[YAMAHAULER]

tan / brown is perfect might be something else

 

[cmburnstx]

Specs for stage 1 hotcam is .06 intake .08 exhaust, correct?

 

[YAMAHAULER]

yes but most of us here run both at .04 or is it .004"

 

[cmburnstx]

Ok cool, I'll reset it down to that just as a safe measure. I had heard of setting it a bit tighter but wanted to hear a confirmation from someone first.

 

[cmburnstx]

Ok re-set valve lash. Something I notice is when I'm setting tdc, the flywheel lines up at the T, but the cam is a half tooth before lining up with the mark. Kinda weird.... if I turn the gear up one tooth on the chain, it of course is the same problem, just ahead of the mark.

????


Also, after setting the valves, I turned it on and let it idle for a minute or two, took off the choke, and ran down the road. At full throttle shifting into second the front tires came up about 3 inches and the bike ran badass all the way into 4th. When I slowed down to make a U-Turn, it bogged and died, and basically ran shitty the whole way back home. I'm gonna pull the plug again and see how it looks, but that kinda makes me think its to rich, causing it to foul when I slow off of full throttle, correct?

 

[lbjamm]

It's not rich, it's lean. That's why I said to move the needle clip from second to third groove.

 

[cmburnstx]

I did, same conditions apply. When it does, occasionally, clear up and run under full throttle, when shifting gears as I left off the throttle it's basically a dead spot in the powerband, then back up again, until I let off for more than a split second, at which point it falls on its face again.

Also, if I leave the idle screw to 1 1/4 turns out per the FSM, the idle seems unrealistically high. If I turn it down to a proper idle, as soon as I let off the clutch to give it gas and take off, it dies.

I drove it around ~1/4 throttle (with the air screw at 1 1/4), and had absolutely no hiccups throughout 1st-4th gear. But then I went to pull the clutch to down shift and turn around, and my motion pro cable snapped. At only about 6 months old mind you. So it's on hold while I go ahead and do the rappy conversion.

 

[lbjamm]

I bet you got an air leak then. You already checked the carb to head boot?

 

[lbjamm]

While it is idling (if you can get it to) spray some carb cleaner around the joints from carb to head and see if anything changes.

 

[cmburnstx]

I put my smoke tester on the carb, nothing from the manifold.

 

[cmburnstx]

Just got a new clutch cable installed, gonna go test and tune some more

 

[cmburnstx]

Problem is intermittent now. Still getting a popping backfire after letting off throttle and coming to a stop. Replaced plug, made some full throttle pulls, pulled it. Plug looks good still. Idfk.