Losses some power when hot, possible leak?

[Cmoped9]

I've got a 2000 elite, I installed a Malossi cast kit on it, Naraku intake, and Polini carb. Scooter runs excellent, but once it gets warmed up it looses some power, doesn't have the grunt like it does when it's cold. Jetting is fairly on, but kind of lean, and I have a 110 main in. All the gaskets are sealed up well, could it possibly be the cranks seal behind the variator?

[Wheelman-111]

Greetings:

I'd be interested in knowing your initial Compression value and current Peak Temps. Also what size of Polini carb?

[Cmoped9]

I haven't checked compression, nor do I know a temperature due to getting a bad temp gauge, and the copper sensor was an oval and allowed the bike to leak between the head and spark plug, so I quit using it. It's a 24mm Polini.

[patthesoundguy]

Id get a new sensor for your temp gauge asap. With out a temp gauge your are flying blind. Could be way over temp and you might never know it, untill its too late that is. If its lean it might be a good plan to go up a jet size to be safe and if the problem goes away after that then the lean condition was likley the issue. If you are worried about crank seals just replace them, its not that difficult or expensive.

[Cmoped9]

No splitting of the case necessary for the crank seal on the variator side? And I've been checking the plug, it's not too lean with the 110, it was worst when I had a 106 in. But something's off, it's not the jetting.

[patthesoundguy]

Crank seal is the easy one because the access is easy.

[Cmoped9]

Here's a current picture of the plug, pretty black. I've been using a quart of bel ray sl2 oil, I don't like it. I prefer the yamalube, but couldn't get it.

[Wheelman-111]

Greetings:

How much oil are you adding? Pump active or deleted? That plug looks like it's either too rich (not lean) or just too much soot from oil, which can disguise and cover a lean mixture.

[Cmoped9]

Pump deleted, mixing 32:1, it still does look rich, parts of the plug look a touch white where it isn't black, there is no chocolatey brown color or wetness to it from being too rich. I believe I have an air leak somewhere, but can't find where. That's why I was thinking the oil deal is potentially bad?

[tazland001]

Are you loosing power everywhere? How are you lows? mid range? and top end? The reason I am asking for specifics is for example, if your loosing power in the first 1/4 of throttle but the mid range and top end is there then it sounds like the pilot might be to rich. Its easy to test. In general if you turn out the air screw more than 2 to 2/1/2 turns and the bike starts to idles like crap and starts to run like crap then your prob rich on the pilot. If you have top end sponge then your rich on the main.

Taz

[Wheelman-111]

Greetings:

Good point, Taz. We tend to forget that a very rich pilot keeps adding at least SOME mixture to the intake flow at all speeds. If the pilot is WAY big, you have to switch to a smaller jet to keep the mid-range working, but then then engine runs too rich down low and leans out up top. You want the air screw turned out about 1 turn, Plus or Minus 1/2. Oh, and don't forget needle position and shape.

[Cmoped9]

Nope, the power lost is throughout the whole range. My pilot is only a 36, so pretty small, I could try a little bit bigger one, but it's not that? It just seems lean across the board, I don't believe it's rich. I think it's black from this new crappy bel ray oil I'm using.

[Cmoped9]

I should note, the scooter runs like a top when it's cold, great power low, mid, and too end for about the first 2-3 minutes, and then slowly looses a little power after it warms up. It still has power when it's warm, but it's a noticeable power loss.

[Wheelman-111]

Greetings:

If it has power when cold, and loses some warmed up, that sounds rich to me.

[Cmoped9]

That's what it seems like, and that's the signs it's showing, but except for the black oily carbon build up on the plug, it's running lean. It's not showing signs of being rich at all, that's why I'm stumped, and believe it's an air leak around the oil seals or something.