RS Vector LTX 2008, missfire

[Tomasagren]

Hello guys

I've got som trouble with one of my sleds. Around 11000km on the dash.

Problem:
Not running on all cylinder on idle and low rpm, and overall boggs when hitting WOT.

But it seems to runt on all anyway, because when I disconnect the ignition coils one by one with engine running it clearly starts to run even worse.

Test performed:
Cleaned all three carbs
New spark plugs
New ignition coils
New rollers in primary clutch


Problems remain

I experience that the sled is quite hard to start.

A little lost on how to get further on this one.
Leak down?
Valve clearence?


Any help is appreciated.



I can try if it would be any help to upload a video of this whole mess

KR
Tomas


 

 

[74Nitro]

Just a heads up about the coils. I've seen guys put rx-1 coils on or the incorrect aftermarket and fry the cdi. Sometimes the aftermarket lists these wrong.

 

[Tomasagren]

Just a heads up about the coils. I've seen guys put rx-1 coils on or the incorrect aftermarket and fry the cdi. Sometimes the aftermarket lists these wrong.

Thanks for your reply, It's OEM P/N installed.

 

[74Nitro]

These engines rarely give internal trouble, but I did have one last year with valve issues on one cylinder. Do a leak down or compression test.

 

[MrSled]

I would toss all the inlet needles, pilots and jets in the grabage and start new. They are known to have carb issues if the carbs are not drained in the off season.

 

[Stubbs]

X2 on what the boss said. The jets in these things are soooo tiny, likely easiest to start fresh and go from there.

 

[RobX-1]

X3 with @MrSled as I was always very meticulous with the carbs on my RX-1 where each year I would disassemble the carbs and thoroughly clean and soak the jets, needles, pilots, etc. and then sync the carbs but at around 10-11,000 miles I noticed I could no longer get the carbs to sync (ie. the lines of mercury were bouncing around inconsistently with each other) and it just didn't run right. Even though I could see thru the smallest of the jets, I came to the conclusion that it was just time to completely rebuild the carbs with new jets, needles, pilots, etc. After doing that, I could sync the carbs where all four lines of mercury were level and reacting the same and she was back to purring like her old self.

 

[MitchRS]

**Edit**

Did you possibly mix up two of the coil connectors when changing the spark plugs? When I did the plugs on my Venture, I had accidentally mixed the connectors for coils 1 and 3 by accident and it had trouble starting as well as rough idle and stumbling when giving it a little throttle.

 

[RobX-1]

When I did the plugs on my Venture, I had accidentally mixed coils 1 and 3 by accident and it had trouble starting as well as rough idle and stumbling when giving it a little throttle.

Considering the three coils for you 09 Venture GT all have the same part number, they are not specific to a cylinder so not sure why mixing them up caused this unless one of them were bad and you were just moving the bad coil to a different cylinder.

 

[MitchRS]

Considering the three coils for you 09 Venture GT all have the same part number, they are not specific to a cylinder so not sure why mixing them up caused this unless one of them were bad and you were just moving the bad coil to a different cylinder.

Are you certain they're not specific to a cylinder per firing order? All 3 of my coils are good, as soon as I swapped them back over the issues went away immediately.

 

[RobX-1]

I know when I replaced the two coils on my RX-1, all four of them were the same part number and they did not have specific cylinder to be connected to. When I checked the coils for you 09 Venture GT, it was the same. I would think if the coils were cylinder specific, there would be three unique part numbers for the coils; how can they have same part number if you need the coil for cylinder #1 and #3:

 

[MitchRS]

I know when I replaced the two coils on my RX-1, all four of them were the same part number and they did not have specific cylinder to be connected to. When I checked the coils for you 09 Venture GT, it was the same. I would think if the coils were cylinder specific, there would be three unique part numbers for the coils; how can they have same part number if you need the coil for cylinder #1 and #3:

View attachment 170128

Because the coils are all the same but the signal for them to fire get triggered at different intervals for each cylinder. There should be 3 pick up coils at the magneto. It's like a vehicle, all coils share the same part number but they're wired to fire for a specific cylinder.

 

[RobX-1]

but the signal for them to fire get triggered at different intervals for each cylinder

Using the parts schematic I posted, if you were to take one of the connectors (#13) and connect it to the wrong coil (#7), then I would agree with you.

 

[MitchRS]

Using the parts schematic I posted, if you were to take one of the connectors (#13) and connect it to the wrong coil (#7), then I would agree with yyou

Oh my, I see where I miscommunicated here.. what I originally meant was the connectors at the coil, not the coils itself.. my bad!

Thank you for pointing that out, I'll edit my original response.