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Loss of power

Posted: Sat Jul 27, 2013 6:48 pm
by Cherreh SR
72 cast molossi, 28OKO 50 and 145 jetting, ct manifold, scorpion pipe, molossi delta clutch and bell, 9to1 gears, molossi Kevlar belt.

After a consistent 20 min of 40- whatever speeds my bike starts loosing power, does NOT die or quit just starts being very gutless and gurgles a bit. What's my problem here? Am I expecting to much to go this long running wise? I'm running 4oz of Motul 800 in a full tank.

Re: Loss of power

Posted: Sat Jul 27, 2013 7:36 pm
by paulpauly7
have you got a temp guage ? whats you temps at

Re: Loss of power

Posted: Sat Jul 27, 2013 7:41 pm
by Cherreh SR
I have no clue. No temp gauge I couldn't find one anywhere local

Re: Loss of power

Posted: Sun Jul 28, 2013 1:16 am
by paulpauly7
ebay

Re: Loss of power

Posted: Sun Jul 28, 2013 2:48 am
by bfowler
Get a trail tech CHT. Need the one for 14mm spark plug
Might wanna pull the head and see what the piston looks like

Re: Loss of power

Posted: Sun Jul 28, 2013 9:52 am
by Cherreh SR
Ok so aircraft spruce sells the westach 100-600 cht and the 14mm type J thermocoupler wire. $66 for the gauge $28 for the wire which is cheaper than I've seen from any scooter part guy.

Does anyone know what was going on when this was happening? Was I soft seizing? What could have been causing this? Maybe my main is to small?

I've never needed a temp gauge on my old arnada in Hawaii and never had these problems.

Re: Loss of power

Posted: Sun Jul 28, 2013 9:55 am
by swimmingfree
have you done a plug crop on it????
swimmingfree

Re: Loss of power

Posted: Sun Jul 28, 2013 11:37 am
by Cherreh SR
Not an official chop where you get it up to temp then put a new plug in, run at WOT then kill it and look.

A real plug chop technically isn't possible on the mopeds and there is no way to install a new plug run it WOT and kill the motor unless you can somehow reach down and pull the cap off the plug at WOT.

I'd say I'm running around 15 to 1. Optimal is 14.7 to 1 but its not possible to get a perfect 14.7 to 1. Can go as lean as 17 to 1 and rich as 13 to 1 but I believe I'm in that 15 to 1 safe zone air to fuel so I'm not understanding why it's doing this.

Re: Loss of power

Posted: Sun Jul 28, 2013 12:25 pm
by Cherreh SR
This is my plug after riding. The white looking ring is just a glare from the metal surrounding the porcelain inside.

Checked my air screw and I'm only 1/4 turn out.
Image

Re: Loss of power

Posted: Sun Jul 28, 2013 9:19 pm
by patthesoundguy
Cherreh SR wrote:Not an official chop where you get it up to temp then put a new plug in, run at WOT then kill it and look.

A real plug chop technically isn't possible on the mopeds and there is no way to install a new plug run it WOT and kill the motor unless you can somehow reach down and pull the cap off the plug at WOT.

I'd say I'm running around 15 to 1. Optimal is 14.7 to 1 but its not possible to get a perfect 14.7 to 1. Can go as lean as 17 to 1 and rich as 13 to 1 but I believe I'm in that 15 to 1 safe zone air to fuel so I'm not understanding why it's doing this.
Use the kill switch it kills the spark same as pulling the boot off. I do plug chops on my scooters. I leave the side plastic cover off, pop a new plug in and do a 1/4 mile or more WOT leave the throttle WOT while killing it so the pilot doesn't scew the results. Pull it and look. Now my question is how much is a full tank of gas, you may need a richer main to compensate for the amount of oil you are using. A CHT gauge is about 40$ from trail tech I have two. You are flying blind with out a temp gauge. Temps can rise with out warning to danger zone from less fuel flow than normal if the the gas tank is almost empty. Anything can happen but if you don't have the information to deal with it a squeaked motor will be the result which in turn means walk home.

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Re: Loss of power

Posted: Sun Jul 28, 2013 9:38 pm
by patthesoundguy
Cherreh SR wrote:This is my plug after riding. The white looking ring is just a glare from the metal surrounding the porcelain inside.

Checked my air screw and I'm only 1/4 turn out.
Image
Unless you do a proper plug chop reading the plug doesn't really tell you much. The idle air screw means nothing at WOT. But it being 1/4 turn out tells you is if it runs properly there is that you might need a bigger pilot jet. You want the screw to be out far enough when it is set right to give you some room to move to adjust for different conditions. A little change in ambient temps could mean you have no more adjustment left in the screw.

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Re: Loss of power

Posted: Sun Jul 28, 2013 10:16 pm
by Cherreh SR
I thought of the trail tech but I'd really like to stick with a mechanical gauge.

Maybe your right about the main, ill have to pull the jets and go up on both.

I'm really just trying to get it right to sell it. It's the first S I've ever built and I'm not liking it as much as my old Arnada. I'm thinking of either selling to buy a ratty S and put a bad * water cooled stroker in it. Or maybe trying a ruckus. Unsure at this point.

Re: Loss of power

Posted: Sun Jul 28, 2013 10:20 pm
by Cherreh SR
Btw a full tank is just about a full gallon so roughly 32 to 1 mixture.

Re: Loss of power

Posted: Sun Jul 28, 2013 10:55 pm
by patthesoundguy
More oil means less fuel, maybe that's all the issue is. I had issues like that with my express, I was messing around with the oil ratio and ran into trouble ;-) you are doing the right thing by sticking with one ratio and tuning to it :-) if you have a larger main I'd try it and see how it goes the worst that can happen is it runs too rich ;-) I'm sticking with 32:1 on my express for now it seems happy there.

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Re: Loss of power

Posted: Mon Jul 29, 2013 6:56 am
by Cherreh SR
Yeah I'll pull the main then and go up. Any recommendations on how big a jump? Up by 2 or 5 or ?