Easy question

[lisfisher]

How can I tell if a thermostat is open or closed upon visual inspection? I THINK my engine has been overcooling , as I have slight carbon deposits on my plug and she is smokeing a bit more than normal. I was told the thermostat may be stuck "open". Now , I just picked up the new part and am wondering how can I tell the current position? I can see part of the spring if that means anything.

 

[DHPMARINE]

Re: Easy question

Assuming is not any way to operate,but the new part is probably 'closed' and if the old part is different,it may be stuck open.

Aiming an infra-red temp gun at the top of the cylinder head helps.Staying at one temp,probably stuck open.It should fluctuate.On some engines you can feel this with your hand.On some engines you can 'watch' this in the tell tale.

Someone may add more so far we only know you have an engine and a thermostat.Hopefully it's a Merc.If you can list a year,model and HP,someone may know more.

DHP

 

[Bob_VT]

Re: Easy question

Do a decarb! You are getting build-up.

 

[lisfisher]

Re: Easy question

Well I put the new t-stat and poppett in last night but I don't think that was the problem causing the excess smoke. Since the day it started smokeing more all of a sudden , I also noticed a clicking sound, more like an arcing sound. I was never able to find the source untill last night when i fired it up after dark. I immediately noticed an arc/spark leak coming from the backside of my bottom coil. No idea why it would do this but anyway i pulled the coil off and the only thing i could see that could possible have caused this is the metal tab that is connected to the negative post ,and the other end is taped onto the backside of the coil. The taped end was not on there very good. When I pulled the rubber housing off the coil the tab fell right off. If this was not making good contact would this arc ? Other than that , what would make the coil arc like this? I don't see any burn marks or anything like that. This is probably why i'm getting excess smoke i would think , because the bottom cylinder is fireing intermittently,causing more oil build up? Motor idles strong and telltale is strong as well , although last night smoke came from the telltale before the water started peeing. HELP! Motor is a 1995 75HP Mercury , serial number 0G199060

PS - Bob VT - are you the same bob VT from CTF?

 

[Bob_VT]

Re: Easy question

Get some dielectric grease and make sure you use it on the plug ins (coils and plug caps). I would even go as far as replacing the wires and caps depending on the age.

Smoke from the tell-tale? That's the first I have ever heard of that. I would do a compression test and start looking through everything.

I would still do the decarb since you have build up.

CTF? No.... active here and on many ATV forums.

 

[lisfisher]

Re: Easy question

plug wires are all new. I'll do the decarb but I'm still confused as to why the coil is arcing.