difficult to start f100

[AGENT 37]

Re: difficult to start f100

It's basically an auto-enrichener as understand. More fuel is provided until the engine reaches normal operating temperature. If the Electrothermal Valve units aren't functioning properly the engine will be difficult to get started/warmed up. I had twin F80's and one would start much easier than the other. I swapped the Electrothermal Valve units between the two motors and the hard starting switched motors.

By the way, through research and cross reference of parts that I've done for the F80, F90, and F100 I've concluded that they are pretty much the same motor with different carburetor parts.

I've also found that firing the motor once when it was cold and then waiting to try to re-start would make it start easier. Probably because it warmed up slightly from the first light off.

 

[strokersquid]

Re: difficult to start f100

Yes, my 03 F90 motor and manual have them . I ordered a manual for my 03 F90 but received one for an F100. I assume they are almost the same or same manual from compareing diagrams in the book w my engine. My F100 manual lists Primestart starting enrichment in the general specifications list. In the carberator section these assembles are called Electrothermal Valve units, #1 and 3 carbs have them on my motor. My motor cold starts ok w/o pushing the key when temps are in the 70-90 degree range but after 2 or 4 trys. It will start w just a bump of the key when the engine is warm out on the lake, w/o pushing the key. When it's colder pushing the key in, momments before trying to crank it, helps it start much smoother and faster. Before i started pushing on the key it could take quite along time to crank in 30-50 temps and would die or idle very rough for several mins before smoothing out. It took me a few years to figure this out. :facepalm: Strokersquid you can check you motor for these assemblies, they are about 6 inches long and mounted to the top and 3rd down carbs and have 2 wires going to each one.

dang, wish i would have seen this a couple of days ago when i had the cowl off checking the oil level, but i took a good look out of curiosity for a choke and do not remember seeing something like that. next time i am out i will look but the weekend is supposed to be miserable so i will not be able to answer for a week or two

 

[strokersquid]

Re: difficult to start f100

also this would explain why when it does start cold it seems to run on two cylinders for awhile, because only two cylinders have the magic choke. but it does seem to start easier when the key is pushed in. perhaps it is wishfull thinking.