72cc Stock Setup Concerns

[Dbroogs]

I know how to punch out the tab in the airbox. I am saying i also took out that extra tab on the airbox cover by the inlet.

[Dbroogs]

yes lid, the picture i posted shows it

[1man8scoots]

I had an air box done like that also, it was ok. Spray some carb cleaner everywhere and see if she dies.

[Dbroogs]

Sprayed carb cleaner on it at every possible place for a leak and nothing. I did have to turn the air screw out another quarter turn but that would just make my idle leaner. Could it be possible i just need a 94 jet? Temps only climb above 380 when I let off the throttle after doing WOT for over a mile.

[1man8scoots]

Check your plug, it tells everything. If it's wet and you're still running high temps you have an air leak you're not seeing. If it's lean and you're 100% sure no air leak up jet. Don't move forward until you have checked.
Wot for a miles and only when you let off do they spike tells you the pilot is too small. I haven't seen my temps rise about 380 on the malossi iron stock set up but I blip the throttle as I decel. You can try setting the mix screw richer and lower the clip/raise the needle.

[Dbroogs]

So I couldn't find a leak with the carb cleaner but when I took the carb off to upjet, the fuel line didn't stop flowing. Could this be a vacuum problem at the petcock or in the vacuum line causing me to lean out? Didnt get a chance to look at the plug after WOT yet, but after I got back from my ride it looked a good chocolate,maybe a bit light for break in.

[1man8scoots]

Do you have fuel coming out of the vacuum hose leading to the petcock as well? If so it is for sure done for. The diaphragm has ripped. It will lead to a lean condition some of the time and a rich others. It's frustrating to tune when it's bad for sure. I replaces mine on my bikes with an eBay on off style and just cut a hole where it sits to access the on off.

[Dbroogs]

Just the gas line is leaking. This didn't happen the 5 times I took the carb off before but now it happens when I have an air leak too, just more problems. If it is just leaking through the gas line then it should be fine right? Just not shutting off which shouldn't hurt my mixture as the float will keep a max amount of gas in the bowl.

[scottinscotty]

I installed the Malossi BBk (Cast kit) have my Main at roughly 92 "Drilled" (Stock Carb with Uni Filter) seems to run great up until 40mph (RPM's Get a Bit High for My Liking) I'm putting in the 8.4's tonight.. Curious to see how she runs.. will post my outcome within the next day or two.. Also my break in period is 0 .. Twist N' Go'.. Baby! ~ My Polini kit was Great, Never a Problem & racked up serious Mileage - I expect the same out of the Malossi!

[Dbroogs]

Well I stripped the motor down and thoroughly cleaned every surface that should be sealed. Put it back together and the only time I have temp problems is half throttle. Max at WOT for like 3 miles is 380 and that is firm. As soon as I go half throttle the temps will jump higher, at one point it went to 400. But if I go to idle and blip the throttle when coming to a stop the temps don't go up at all, weird but manageable.

I now have a 92 in for the main and rich needle position, 1.5 turns out a/f screw.

Max speed is over 55! But I was tucking pretty good. Sitting upright knocks off at least 3mph depending on the wind.

She still doesn't have as fast an acceleration as I expected but that is probably the 5k old clutch. Good enough for me though.

[Dbroogs]

Top Speed Run

[1man8scoots]

Majority of times if it's flowing out with out the fuel line with out vacuum the plunger inside the petcock is stuck. You can try tapping on the petcock itself to try to free it but more than likely it will rip soon. I've never seen one not eventually rip and flow out of the vacuum tube but it could happen and you're semi ok. I would replace it to avoid worse problems later.

[scottinscotty]

8.4's Installed and the Scooter moves as good as ever! I was dumb founded as there was very little loss of low end power as it seems this Malossi Kit as Tons of low end Power!, I'm running rougly 50'ish mph' and have no problem getting there! I look forward to adding more components to make this puppy Scream! The Polini Kit was nice but Def. a higher Rpm Cylinder & a Bit more Difficult to Tune. By the way I'm running a completely Stock Drive Train Minus the Gear & De-Restriction!

[Rancher1]

That's good to know Scott as I'm running the same setup (plus Polini vari). I haven't run it yet - waiting on new trans gasket. I was a little concerned about the 8.4:1 hurting low end, but I guess the Malossi cast with small carb and stock pipe likes to make torque at relatively lower RPMs. What's your next upgrade? I was thinking about a quiet(ish) pipe like a V8 but still thinking and want to run the bike as is for a little bit.

Dbroogs, not sure if you're following my other build thread but I'm running a similar setup. For my bike/location, #96 main felt slightly on the richer side. I haven't checked temps or plug yet however. Point being, you could try upjet a size or two and see how she likes it. From your temp readings though, it looks like it's close.

[scottinscotty]

Already tired a cheap variator that I had on the shell... believe it or not the stock was sooo much better! Im think my next install will be a V8 pipe.. im guessing im going to have to richen up the fuel a little. Half tempted to go 7.4 for some 60mph low rpm cruising.