Epic Failure...

[HDKILA]

For those who have been following my situation I installed the new carb boots today to no avail. I feel like I have done everything possible to fix this high rpm miss. Here is a short list of the things I already have done to resolve the situation.

1. Drained tank and had it cleaned and epoxied.
2. Sent Carbs to get cleaned/replaced fuel filter
3. All new plugs/wires/caps/coils/RectifierReg/Ignition
4. New Carb boots
5. Countless Synch's.

WTF else could I be missing? The fuel pump seems to be spitting hard...The vboost boots look o.k.

Right now me and my max are feeling like big losers...help!:bang head:

 

[pegscraper]

For #3, does that include checking the ignition module, or swapping for another known good one?

 

[gamorg02]

i'm not expert, theres a lot of guys here that know more, but COULD this be the battery? high loads at high RPMs and it jus tcan't keep up? maybe try fully charging the battery and take the bike out and see if its better and then gets worse over time? try replacing it maybe? just my $.02...

 

[HDKILA]

For #3, does that include checking the ignition module, or swapping for another known good one?

i swapped for a known good one...

 

[HDKILA]

i'm not expert, theres a lot of guys here that know more, but COULD this be the battery? high loads at high RPMs and it jus tcan't keep up? maybe try fully charging the battery and take the bike out and see if its better and then gets worse over time? try replacing it maybe? just my $.02...

New battery installed in october...I keep it on the tender during the winter and it was definetly fully charged.

 

[naughtyG]

Can you describe the exact symptoms again in detail?

 

[hubeerjw]

Have you done a compression test... just an idea? If it is running just fine at low RPMs I woldn't think it would be a mechanical problem with the engine, but who knows. Is your crankcase vent plugged? (the one that goes into your airbox? I know that you can sometimes see a fair amount of white-ish oily stuff build up, but still shouldn't cause high RPM misses. What needles are you using in your carbs stock, stage 1, etc?

 

[Heretic]

Well the first part would be to identify what kind of miss it is. Going to the very basics; air, fuel, and spark. Do you have a dyno in your area that has the ability to measure air/fuel mixture? If you can determine that your air/fuel mixture is right on the top end then that will eliminate a lot of possible issues. Running too rich or too lean can cause a 'miss' type problem, or popping on the top end. Also while its on the dyno I would see if they have the ability to check for spark using a sensor that attaches to the spark plug wires. If the spark gets wacky on one cylinder at high RPMS that will narrow the possible problems.

Have you checked all the vacuum hoses on the bike for cracks and what not?

Have you sprayed around the carbs and vacuum hoses with some carb cleaner while the engine is running to see if it causes any changes in idle speed?

I have missed your previous threads, as others have apparently. Tell us exactly what it is doing and what you have replaced and checked. This forum has the greatest collective knowledge on the V-Max in the world. I am sure that we can get your bike humming perfectly before spring time.

 

[richwrench]

Did you happen to notice if the tach dips when it happens ? That would prove electrical instead of fuel. I had an issue like that early this summer. Turned out to be a corroded ignition switch connector - never would have guessed that myself. Was fine at lower speeds...

 

[robsplatf4]

WTF else could I be missing? The fuel pump seems to be spitting hard...The vboost boots look o.k.
View attachment 5767

You might try to open up your fuel pump and check that the two little diaphragms are in place. I had one pop out and cause a high speed hiccup. Its quick and easy to check.