85 Formula Plus - Snowmobile Forum: Your #1 Snowmobile Forum

Rustybux · 01-20-2008, 06:13 PM

Still problems with my 85 Formula Plus,,my MX runs terriffic.
Is it possible to put a little electric fuel pump like found on garden tractors and wire it into the electrical system so it works when the engine is started? That would be cheaper than the pump that is on it now I think. Went riding and got up to 6000 rpms then it slowed to 5000 rpm then just shut down...would not start, plugs dry, primed about 10 times and still dry plugs.
thanks for any help you people give me.

Ditch hopper · 01-20-2008, 06:33 PM

hey rusty glad to see yah back around

no a tractor fuel pump will not work as it wont supply enough fuel to the motor check your local cycle yard, and ebay or u can buy a rebuid kit for about $120 if my memory servers me right

Jim Jessup · 01-20-2008, 06:58 PM

FYI; you can buy a brand new complete OEM Mikuni pump for $35.00. It should have fired when you primed it though. Ten is way too much, three pumps I find is the most I can go on my 521.

**smallengineguy** · 01-20-2008, 08:52 PM

Remove the lines from the carbs and pull it over (it DOES have fuel in it, correct?). See if fuel shoots out of the lines. If not, there is an obstruction in the tank or lines. The pick up line may have broken off in the tank so it can't reach the fuel.

Rustybux · 01-21-2008, 12:09 AM

When it died on me, there is fuel in the lines but maybe the pump just was not pumping. How much pressure does it need to supply fuel? Ditch Hopper? Thank you and I am back but been busy trying to figure out this problem.
IT has spark and can't figure out why it just slowed down and just died other than fuel pump. I'm old and I get very tired pulling the rope more than 3 times, LOL. Why did the plugs stay dry after priming 10 times is beyond me.
I wonder if I can blow back through the lines from the pump to the tank and see if it's obstructed. My 87 MX starts on the first pull and the Plus should too.

After overhauling the carbs, my sons took them out and the same thing happened to them and had to tow it back. Does everyone think it's Fuel problem?
again, thanks for all the advice..I feel i'm bothering everyone with this problem.

Oh, Rustybux was the name of my pet house rabbit if anyone was wondering. haha

jimmyv13 · 01-21-2008, 09:29 AM

I'd think something is blocking the pickup in the tank or the lines.