Pinging

[JOEX]

Took the quad out today to break-in the new top end. Over all it runs great except when the rpms are kinda low and I get on the gas it starts to ping, it gets worse as the motor gets up to temp but it wasn't running hot at all. I can down shift and bring the r's up without it pinging. There is no sputtering on acceleration and no popping on deceleration, riding at sea level.

There also appears to be some oil leakage above the head, haven't investigated this yet. The gas has been in the tank since last September and I haven't checked the plug yet.

Where should I start to look for what's causing the pinging? I haven't check the valve adjustment since breaking it in, that will happen tomorrow;) I shouldn't need to run race gas with this set up and i'd rather not.

Motor specs:
Ross 416 10.8
Hot Cams stage 1
Ported head
No base gasket
XR400 head gasket
Spark's timing advance key
Powerbomb header
E-Series pipe
K&N Filter
No lid
162 main jet
42 pilot jet
Needle clip in the middle
Mixture screw 2 1/2 turns out
DPR9Z plug
Tinner scoops
Stock CDI


Measurments I took while putting it together:
Deck height was .043" with the xr400 base gasket and .031" without it.
Squish using the piece of solder method was .065"

I'm not sure how accurate these number are, they don't seem right (too big) from what i've read recently.

Thanks, Joe:)

[EPDP99]

just for giggles try a higher octane. that kind of pinging sounds like pre-ignition because it gets worse when hotter.

[balls2da-wall]

best bet is to change that gas out and spark plug:D

[JOEX]

My wallet doesn't giggle much:eek: :p I may give the race gas a shot next weekend.....

The old gas didn't occur to me until I got back and the plug is brand new;)

[balls2da-wall]

you should be fine with pump gas...90octane or higher...I run a 440 with 11:1 compression in harescambles in the dead of summer (92+ degrees) and all i run is 90octane gas and have never had a problem

[JOEX]

Yea, I should be fine with 92 which is what is in the quad now. I'm guessing the outside temp at the dunes was around the upper 60's to low 70's with a breeze.

[TCracin440ex]

the oil comming from away from under the head is a blown headgasket....not unless you dont have the head torqued to specs...

the ping might be predetionation....with that low of a compression ratio i dont think you should have predet. but its possible...and predet will cause to you blow a headgasket too so check into that

[TCracin440ex]

oh i just read your motor mod list too....you might want to try and take that advance key out because i read somewhere that the advance keys dont do well with modified engines....get rid of the key and get an aftermarket rev box that does pretty much the same thing the advance key does it advances the timming.. and you gain an extra 1000 rpm

[JOEX]

The oil is coming from above the head so i'm thinking the valve cover gasket or a bolt.

I was thinking it's the timing key too but i've heard of others running it with more mods than me with no problem.

[Silverfox@C&DRacing]

the key is fine in a 416 but will run hotter and need higher octane fuel.

[FoxRacing81]

pinging or clicking?...You have a hotcam stage 1 and as the motor warms up it'll tick...if you mean pinging though...I agree about trying some higher octane gas...just to see wat happens.

[TCracin440ex]

valve cover gasket...but yea try the gas...i kno you really dont wanna hear run race gas but you could always mix a 93oct with 110 that should cut down on cost for your gas

[Colby@C&DRacing]

Like dusty said the key is fine in the 416 but you have to run race gas. The pinging you have is caused by old low octane fuel. You can run a 416 on pump gas but with the key you need more octane:)

[DiRTdiGGr660]

sure its timed 100% right?

[JOEX]

Thanks for the info:)

Any idea on what octane to start with? I suppose it's trial and error.....

When mixing pump 92 with say 110 in equal portions does the final octane always equal 101? (92+110)/2=101 or (89+110)/2=99.5 etc.

[cals400ex]

my buddy runs his timing key in the 416 and runs just fine on pump fuel. we never had any problems with his. i would definately put new gas in it. you could try race gas and see if you wanted though.


yes, the stage 1 hotcam is very loud. make sure that isnt' what your hearing.

[cals400ex]

also, what happened to the LTE's?

[JOEX]

Originally posted by cals400ex
my buddy runs his timing key in the 416 and runs just fine on pump fuel. we never had any problems with his. i would definately put new gas in it. you could try race gas and see if you wanted though.


yes, the stage 1 hotcam is very loud. make sure that isnt' what your hearing.
It's definately not the valves, that's a totally different noise:eek: :p

I'll try new gas first then a race blend and see how it goes, hopefully Monday or Tuesday.

The LTE's are itchin' to be installed but I want to get everything dialed in with this set up first so I can get a decent comparison between the two exhausts;) I might be putting them on when i'm at St. A's next week:D

[cals400ex]

well make sure you post a review with those bad boyz on because i am itching to hear how they do. :D

[wilkin250r]

Hmm, I've been busy for a few weeks, haven't been on. I missed this thread.

If you're running a .065" squish, I highly doubt you're at a true 10.8:1. As such, I would also doubt that this "ping" is detonation. However, you DO have the advance key in, and you're certainly running higher compression than stock, so it may be detonation.

Describe this ping... Would you suspect it is detonation? If it happens when you get on the gas at low RPMs, that would seem to indicate detonation. Most non-motorcycle engines have a timing advance as RPM increases, but I don't think ATVs do. As such, any timing advance will be more pronounced at low RPMs. When you get on the gas, and let more air in, cylinder pressures increase. The combination of more air and timing advance may give you detonation.

Then again, I still doubt you're running high enough compression to really worry about it.

Did you do a compression test?

Did you try race gas?

[JOEX]

It starts to ping when I get on the gas at lower rpms or climbing a hill in a higher gear. Haven't done a compression test and didn't get to ride enough to try race gas due to a broken shifter shaft:(

The timing key will be removed when the motor get taken apart.

What other types of ping are there?

[Nate408]

My bike pings quite a bit on 91 pump gas, which is about the highest octane commonly found here in northern oklahoma. Im running a hotcams stage 2 and stock bore je 10.5:1 with C&d thin cometics. the head has not been decked. Running 111 phillips mixed with pump 91 works pretty well unless it really hot (90+) or riding at the dunes. I tryed running mixed gas a couple of times at sahara pinged like *****, so straight race gas only on the sand. I before i switched race gas i tryed richening it up till it just fouled plugs big time and still pinged, so im sure it wasnt too lean. Hope that helps some.
Nate

[khen]

Originally posted by Nate408
My bike pings quite a bit on 91 pump gas, which is about the highest octane commonly found here in northern oklahoma. Im running a hotcams stage 2 and stock bore je 10.5:1 with C&d thin cometics. the head has not been decked. Running 111 phillips mixed with pump 91 works pretty well unless it really hot (90+) or riding at the dunes. I tryed running mixed gas a couple of times at sahara pinged like *****, so straight race gas only on the sand. I before i switched race gas i tryed richening it up till it just fouled plugs big time and still pinged, so im sure it wasnt too lean. Hope that helps some.
Nate Mine pinged like crazy on 91 octane at the dunes as well. I tried mixing in 1/3 race gas and is still pinged.. went to a 50/50 mix and it did better. But unfortunatly by that point I let it ping to long and it overheated and pulled the headstuds. Now I'm starting to wonder if a high compression piston in the 4??EX is a bad idea if you ride the dunes to hard. :confused:

[F-16Guy]

I would definitley take out the advance key. You don't need that much initial advance. You should have all the low end you need; what you want now is a more aggressive curve, if anything. My 416 knocked pretty bad when it was under a heavy load on pump gas (low R's, dunes, etc.), but that seemed to be more prevailant during break-in when everything was tight. In most cases, I can get away with 91 octane as long as I don't push it too hard. Get rid of the key first (which will probably make it run cooler, too), and then if you still have problems, go to a 50/50 mix.

[balls2da-wall]

climbing a hill in to high of gear and gunning it at low RPM's...hmmm mine does this too but its not pinging...its clicking! dont know for sure what it is but everyones i know does this.

[EPDP99]

i run half race in mine. i have had good luck with half race /half av. at the dunes. 110+100 octanes.