Burned a valve....

[cjmech]

Had the bike tuned Friday, hit the track yesterday and got 5 laps and she was done..... Whole lot of money for nothing and now I have to tear it apart again after just rebuilding it a few months ago.

Pretty sure I need Valves on the front cylinder. Anyone have reccomendations on what valves to get and where to get them?

Thanks for any useful information.

 

[UMDterp13]

Pretty sure the valves are same as one of the big twin motors. I'll check tomorrow

 

[Theycallmecrash]

Stock

 

[lawdog]

Did you do head work with your big bore kit? I would send them to Hammer to be worked over to compliment the big bore kit install. Are you sure it is bad valve? Were you still running a little lean up top?

 

[gbalias]

define 'tuned'

 

[lawdog]

define 'tuned'

Dyno Tuning Post

Big Bore Kit Install Post

 

[gbalias]

thats not giving us much info.

a few pulls with AFR reading id hardly 'tuning'

we're talking about changing displacement and no considerations were made for ignition???

no wonder it didnt last long.

id find a new shop.

 

[cjmech]

Love how you guys on here miss the point of the post every time... my question was about where to find the parts and what vendor might have the best ones to use in these engines.

I didn't ask for anyone's opinion on why it happened or for advice on tuning so i wont be getting into answering the questions above.

If someone has information on the original question it would be greatly appreciated.

 

[Matteson]

Stock

There was your answer.
I believe they were trying to help find a solution to your problem so that after you purchased new valves you could avoid this from happening again.

 

[gbalias]

my intent wasnt to be harsh.

i was hoping to narrow down a reason for not having to do it all a third time.

 

[cjmech]

Well after doing a compression test on the bike I found that its not a valve issue. I checked the resistance on the plug wires and coil which all test fine.

Anyone know how to test the CPS?

Thats the only thing I can figure is wrong at this point.

 

[gbalias]

key on, ignition on, in gear, rotate rear wheel until you hear injector cycle. if not cycling, there is something wrong

it should happen when timing mark is in window.


wouldnt hurt to also check connections.

 

[gbalias]

Love how you guys on here miss the point of the post every time... my question was about where to find the parts and what vendor might have the best ones to use in these engines.

I didn't ask for anyone's opinion on why it happened or for advice on tuning so i wont be getting into answering the questions above.

If someone has information on the original question it would be greatly appreciated.

dunno if it would upset you to ask for symptoms since its not pertaining to the valves, but ill shoot....


what is it its doing exactly? and why did you automatically fault the valves? where did you come up with your procedure for diagnosing the issue?



sometimes you may think information not pertaining the the question is irrelevant, but to the right experienced person, it may make a difference. so dont be so quick to knock down inquiries.

 

[cjmech]

thats not giving us much info.

a few pulls with AFR reading id hardly 'tuning'

we're talking about changing displacement and no considerations were made for ignition???

no wonder it didnt last long.

id find a new shop.

This is the only post that bothered me honestly. Most of the others were irrelevent.

I spent about 5 hours on the dyno tweaking the fuel and ignition maps along with the guys there running the dyno. So the above was a just a bunch of assumptions. The tuning was about as perfect as we were going to get it for cruise but WOT we were maxing out the injectors and only getting about 14:1 AFR flat from 3-7k(yes I know this is lean as optimum power on pump is generally around 13:1) Anyway the bike was running 100% better than it ever has, no more popping on decel and it ran perfect for the next 75 miles of in town riding prior to the track day and never skipped a beat. At the track on one of the last laps it started bogging and would not hold rpm in the turns with the bike at about 4-5k rpm. Open the throttle and you could feel it trying but it just wasnt there. Upon track exit the bike would not idle and just stall. It would start back up but I would have to hold it around 2500-3k rpm. Parked it, let it cool off and plugged in the ECM Spy to check to see if there were any codes (None) did a TPS sweep and didnt have any issues. Compared the map to the saved tuned map and nothing significant had changed. Start it back up and tried to keep it running for a few minutes while using an IR temp gun on the header to see which cylinder was having an issue. The front header temp at the head was only showing about 250 deg of heat while the rear was around 600. Pulled the plugs and they looked the same as they were new prior to the tuning session (clean and not shoing any lean or rich condition) Started and attempted to get the bike to idle a few more times and it would try to idle but then backfire thru the intake and then flutter/exhaust thru the maniflod and die.

The backfiring and coughing back up thru the manifold is what made me suspect the valves combigned with the lack of heat out of the front cylinder.

The fuel pump and pressure regulator are also new.

 

[rchuff]

^^^^ What gbalias said. :up::up:

 

[ReadyXB]

Wouldn't an issue with the CMP affect both cylinders? Have you ruled out an issue with the front injector?

 

[cjmech]

No I havent rulled that out yet. But also why I am looking for information on how to check it. A new one is almost $170....

 

[ReadyXB]

What about swapping the front/rear injectors with each other, and then check the rear header temperature.

 

[gbalias]

so now we have a full story and a much, MUCH better place to start...........

and i do believe ReadyXB is on the right track. 1st thing I would look into is that front injector. Swapping them is a decent way to quickly diagnose but they have a specific spray pattern for front/rear, so you cant keep it in there if you swap em for purposes of diagnostics.


based on your sequence of events, i would have said it WASNT tuned if youre still lean at WOT. there is nothing to suggest the injectors would not be able to keep up even at WOT. there is ALWAYS a safety factor when engineers select injector sizing and volume for any given application. I do not believe the modifications made to your bike would have overcome those limits of design.


that being said, my previous posts still stand. look where we have come already....from rebuilding top end, to CPS, to injector. 2/3 are not the issue. We could have probably come up with the fueling as a fault had we heard the symptoms from day one. imagine how much time/money it would have cost if you started throwing parts at it. see.....we do care about our fellow members! lol

but then again, i guess all you wanted to know was which brand of valves to use.....so in that respect, i apologize....i had nothing to offer. I really am here to help in subjects i happen to have a little bit of knowledge on. I believe a few people here can vouch for that.


as a matter of fact, I created a post a while ago in this VERY similar subject (fueling at high demand)

http://www.buellxb.com/forum/showth...cs-as-Promised&p=523744&viewfull=1#post523744


see if that helps point you in the right direction :up:

 

[gbalias]

in regards to tuning ignition maps......was this done on a steady state dyno with throttle position & rpm feedback to dyno pc?