Complete engine shutdown @ 75mph after a 130 mile ride, any ideas?

[luvmythumper]

SYMPTOM: While doing 75mph WOT for approx 30 seconds, the bike just

stopped as if I pressed the kill switch. It still has compression, so

the piston was not blown. And it has spark.

BACKGROUND: We were 130 miles in, approaching our campsite (30 miles

shy) when this happened. Up until then the bike was running fab! Its

my first BRP and its a clean '02. I had the pig un-corked before

going out on my first ride.

THINGS TRIED:

OVERVIEW 1) plug sparks

2) put gas in the cylinder, still no start

3) looked for elec shorts due to wear/vibration

DETAILS: I pulled the plug, it looked a little on the dirty side,

but it sparks! Good spark at that. The tail light lights up when I

kick it, I assume this means my coil and electrical is good. I checked

the wiring from the coil back to the regulator (?)- looking for

vibration wear into the wire insulation, found nodda thing. I put gas

on the sparkplug and in the hole then installed the plug and kicked it

over, not the slightest of an ignition occurred, just like the kill

switch was held. So I disassembled the kill switch, no change.

PLAN OF ACTION: 1) get a new plug and hope and pray.

2) hope someone has other ideas what to do??

[TREADMARKS]

I had the pig un-corked before

going out on my first ride.

I betcha it was running way lean on the topend after the uncorking, got hot, and jumped time.

I have had theat happen to me on an older airhead after uncorking.

Good luck! ?

[pchansen]

I had a old YZ that somehow striped the woodroof key that held the flywheel in place. The flywheel spun on the shaft and that was the end of my day. Longshot I know, but what the heck.

[-=Jughead=-]

OK, some possible idjit checks (Hey..., stranger things have happened ? ):

Gas flow is unobstructed?

Intake manifold leak?

Jet is clogged?

Plug wire not arcing anywhere?

Choke OK?

Carb throat clear?

Water in fuel?

[BWB63]

Details of the bike?

What is it?

Jetting?

Header/Muffler, air filter?

Un-corked?

New/old?

Other Mod's?

[luvmythumper]

Thanks for ALL the ideas. Timing seems to make alot of sense given the symptom? Ok, what does it take to check this?, if the chain jump, if the timing is ok or not?

Details of the bike? I have answered below.

What is it? ANS: 2002, CLEAN, bought it from someone who needed to take it in to the shop to get it to run, probably sat too long and gummed up. It appeared to be his first bike and was riden only a handful of times very lightly by all accounts of the beautiful condition it was in, the only drawback was it was 100% stock.

Jetting? ANS: the un-cork setup - 68 std pilot and a 175 main with the un-cork tube that goes between the needle and the main (dont know what that is called but it was tricky figuring out how to get it out.

Header/Muffler, ANS: normal air filter? stock muff with un-corked core.

Un-corked? ANS: yes, still has the air pump, just got the block off kit but did not install it yet.

Will keep you all posted! thanks. CCRIDER1980

[Winkel]

A friends son's XR80 was having a similar problem. Getting gas, spark, etc. Decided to adjust the valves, and when I removed the side cover, found the problem. He had thrown the chain a couple of weeks earlier, busted the case, and a piece of the case had bent the bracket that held the spark pick-up. Adjusted the pick up, and it now runs fine.

I know the cases are different on these bikes, but it might be something to check.

Winkel

[Eric_and_Liz]

I agree with the guys above. If you know that you have good blue spark, Compression in the proper range, and fuel getting to the cylinder then the only thing that It can be is timing.

I have a question regarding the BRP however. Are these clearance fit engines? IE if you slip a timing gear or break a timing chain are you in danger of bending a valve or doing catasrophic damage to the piston/valve/con rod?

Just curious here in Okinawa living vicariously through you all.

Eric

??

[luvmythumper]

FIXED,

ROOT CAUSE FOUND!: The problem was lack of gas going into the the cylinder, it was carburator slide valve, more specifically it was the Link Arm, the 2 screws vibrated completly off the Throttle valve. Thus the needle and Throttle Valve were not moving at all when twisting the throttle handle. But the throttle still sprung back giving the false impression that it was working normal.

So it was from when I un-corked the pig the week prior to my ride, I did not tighten the screws well enough after switching the needle - due to the angle of the screwdriver to get to the screws. So when I found this out, I totally disassembled the LINK ARM to get access with a straight approach and tighten those buggers. ?

[Jigggawatt]

I always use blue locktite on those screws.

[bork]

you should be thrilled !!! not timing chain! ?