Rev limiter, Jetting or Stator?

[JOEX]

The motor is breaking up at upper rpm's.....

Current set up:
416 Ross 10.8
No base gasket
Thin head gasket
Ported head
LTE Dual Exhaust
Hot Cams Stage old Stage 2
Stock carb: 45 pilot, 180 main, needle clip in the middle
K&N Filter
No Air box lid
DPR9Z plug
Stock gearing

I'm not sure if it's hitting the rev limiter because it starts to break up very quickly in the fist three gears unless I shift real fast, get to third in what seems just a few seconds. Would this set up rev that quickly? I tried a 178 main and i'm pretty sure it was too lean. This was in sand BTW.

When I first took it out last week with a 40 pilot and 180 main it didn't do this.

After searching some jetting posts there was mention of the stator going out or coming loose causing similar symtoms. I did have the stator removed while replacing the shifter shaft. Is there a way to check the stator without removing the side cover?

Any other ideas what to look at?

[wilkin250r]

How's the power before it starts cutting out?

For $30 you can get a cheap tachometer, and verify what RPM it starts cutting out. This would give you a good idea if it's the rev limiter.

Or, you can get the same information from a dyno test at a local race shop. $20 is a typical price for a dyno run, and they can probably give you some advice on what the problem might be (if it's not the rev limiter).

I can't imagine the stator being the problem.

Jetting could be the problem, a plug chop could tell you that.

[UglyMotha™]

sounds like shes rich to me i can't see you needing that big of a main hows the plug look

you can check the stator with a volt meter specs are listed in the service manual and tells you how to do so

i had a simiallar problem her recently mine would break up past half throttle turned out i had a weak spark replace every electrical compent turned out i had a bad ground on the coil

[400exrider707]

Originally posted by UglyMotha™
sounds like shes rich to me i can't see you needing that big of a main hows the plug look

you can check the stator with a volt meter specs are listed in the service manual and tells you how to do so

i had a simiallar problem her recently mine would break up past half throttle turned out i had a weak spark replace every electrical compent turned out i had a bad ground on the coil

Yeah sounds rich to me as well.

[JOEX]

Where do I find an accurate tach for $30? A dyno run would be nice, didn't think those were that inexpensive.

I did a plug chop with the 178 and it looked lean so I went back to the 180, it may not have been accurate though it was the first time for me doing that.

What confuses me is it didn't break up last week but yesterday it did, same riding location but a slight bit cooler. That's why I brought up the stator issue, maybe something loosened up. I did stop at the powerwasher on the way home to clean the sand and salt off. I'll check the stator & electrical connections.

The jetting probably still needs some tweaking too.

[wilkin250r]

Originally posted by JOEX
Where do I find an accurate tach for $30?
I don't know if you need super-accurate, or really fast response. I would imagine anything accurate to 100rpm would be just fine for general diagnostics.

www.tinytach.com

[K_Fulk]

Originally posted by UglyMotha™
sounds like shes rich to me i can't see you needing that big of a main

I agree.

I tried running a 165 when I first got a full pipe and had the same problem. It would run fine till the main jet kicked in, then would just feel like it was hitting the rev limiter. Went down to a 155 an then it ran great.

[cals400ex]

i never ran that rich either. however, i tended to run on the lean side because it was a little quicker that way.


however, that setup should pull to the stock rev limiter really easy too. i would nail my stock rev limiter in the 1st 3 gears when dragging, sometimes even 4th. most don't hold it in gear as long as i do but my bike was quicker that way.

[JOEX]

I was thinking the dual exhaust would require a bigger main jet, maybe the 180 is too much. I wont be able to mess with it until this weekend at Coos Bay. BTW the changing the main jet is a PITA with this exhaust, especially with a hot motor:ermm:

The only other difference was the gas I used this week came from a different can than the gas I used last week, both were 92 octane. I'm pretty sure I filled both cans at the same time last June.

[dork]

i had a 350x recently that would do that. really seemed like a jetting issue, since it was using a different carb. turned out to be the cdi. funny thing is, the cdi was fine when it was parked 2 years ago.

[JOEX]

I tried it with a 170 main it ran alot hotter and pinged some when it was hot, did a plug chop and it was a light ash color. At idle the plug a tad on the dark side.

I haven't check into the electrical system yet...

Any chance the valves are floating? Still running the original springs (2001) but I don't get to ride much:ermm:

[mikeboone]

Originally posted by JOEX
I tried it with a 170 main it ran alot hotter and pinged some when it was hot, did a plug chop and it was a light ash color. At idle the plug a tad on the dark side.

I haven't check into the electrical system yet...

Any chance the valves are floating? Still running the original springs (2001) but I don't get to ride much:ermm:

If you pulled the stator be SURE the 3 8mm bolts are locktited in. I had one of mine back out and ground up inner flywheel and pickup. If you hear any scraping noise you better stop :eek:

I had intake spring break on my 440 after 1 year and it was aftermarket. Stock springs you have may be weak after than amount of time as they are under 24 hr pressure.

[bwamos]

Have you tried a 185?

I think your lean, not rich.

It's cutting out not sputtering, correct?.

[POW 352]

hey not sure if this is ur problem but my 300ex did that when the nuetral sensor on the engine cracked... with the quad in nuetral rev it up and see if the light dims out if so theres your problem it fakes out the rev limiter

[JOEX]

Originally posted by bwamos
Have you tried a 185?

I think your lean, not rich.

It's cutting out not sputtering, correct?.
It sounds like it's cutting out, I think..... not how to tell the difference:ermm: The 180 is the biggest main I have right now.

I did locktite the bolts on the stator.

I'll check into the neutral sensor too.

[wilkin250r]

A 180 is huge, and way bigger than you should need. If you're still lean with a 180 main, then you have problems somewhere else!

[JOEX]

Originally posted by wilkin250r
A 180 is huge, and way bigger than you should need. If you're still lean with a 180 main, then you have problems somewhere else!
Even with dual exhaust?

I tried contacting LTE about jetting but haven't heard back:ermm:

[UglyMotha™]

Originally posted by bwamos
Have you tried a 185?

I think your lean, not rich.

It's cutting out not sputtering, correct?.


lean creates a bog.......




joe have you checked your spark yet, few weeks ago mine would sputter at half throttle and past, turned out to be a week spark

[UglyMotha™]

Originally posted by JOEX
Even with dual exhaust?

I tried contacting LTE about jetting but haven't heard back:ermm:



sounds huge I can't see how you would be flowing more than me, i mean i do have a single exhaust but i'm running a 42mm khien carb and my main jet is only a 165

[JOEX]

Originally posted by UglyMotha™
lean creates a bog.......




joe have you checked your spark yet, few weeks ago mine would sputter at half throttle and past, turned out to be a week spark
Haven't checked it yet, it's fairly new though only had about 5 hours on it.

[UglyMotha™]

Originally posted by JOEX
Haven't checked it yet, it's fairly new though only had about 5 hours on it.



my coil lost it's ground for some reason, after i ran a new ground to it, she was strong again, pull you plug and stick it against the jug and crank her over, see if you have a nice strong spark if, it's faint, it's goin to sputter, when given a certain amout of throttle, if you do have a week spark it could be the ground, stator, pulsar, regulator, have you gotten the chance to test the output of the stator with a volt meter yet, the specs are in the service manual

[JOEX]

Originally posted by UglyMotha™
my coil lost it's ground for some reason, after i ran a new ground to it, she was strong again, pull you plug and stick it against the jug and crank her over, see if you have a nice strong spark if, it's faint, it's goin to sputter, when given a certain amout of throttle, if you do have a week spark it could be the ground, stator, pulsar, regulator, have you gotten the chance to test the output of the stator with a volt meter yet, the specs are in the service manual
Not yet, i'm in the middle of a 13 day work week:ermm:

I also need to get a new multimeter and the manual says I need a peak voltage adapter to check some of the items, gotta find that too.

[JOEX]

I checked the plug spark, tried a couple of old ones I had laying around too and the current one seemed a bit weaker than the others. I'll get a new one and hopefully get out next week to try it out.

I still plan on checking the electrical system too.

[wilkin250r]

If you suspect a weak spark, try an Iridium plug. They're expensive, but the smaller electrode on them requires less voltage to fire. Just be careful gapping, you can't gap them like a normal plug.

It's not an end-all cure to all your ailments, but if the Iridium plug gives a noticeable improvement, it would indicate that your spark may indeed be weak, and give you an area to focus on, rather than stumbling blindly through the dark.

[bwamos]

Originally posted by JOEX
It sounds like it's cutting out, I think..... not how to tell the difference:ermm: The 180 is the biggest main I have right now.

I did locktite the bolts on the stator.

I'll check into the neutral sensor too.

If you haven't removed it..... try turning on your choke a 1/4 of the way. If it runs better your too lean.

[JOEX]

Originally posted by wilkin250r
........ rather than stumbling blindly through the dark.
I do that quite well thank you:o :p

Where would I look for an Iridium plug and a cross reference for the NGK #?

What's the difference in gapping?

I still have the choke and i'll try that too if I ever get the chance to ride again:mad:

[UglyMotha™]

Originally posted by JOEX

What's the difference in gapping?




he just saying be careful, when gappin a iridium plug you can't pry off the electrode, you'll break it

[wilkin250r]

Bingo.

When you're gapping a normal plug, you often stick something inside the gap, and pry between the electrode and ground strap to increase the gap.

If you did that with an iridium plug, the electrode is so small it will break. You have to use a small set of needle-nose pliers, or a special tool to bend the ground strap by itself without prying against the electrode.