Grey Plug

[Willfulone]

Just did a plug check after installing a HFM slip on and a 175 jet that came with the pipe...

The plug is grey...which as far as I know means to lean...

Everyone on here recommended a 155-165 main jet.

Does this mean I have to go up in jet size???

The is no hesatation or stumbling at top end.

Tks

http://forums.atvconnection.com/i/GalleryImages/26127/MVC-025F.JPG

Peace
Willfulone

[Greg Z]

ok this is what u do Warm up the quad..... then change the plugs and then check it you will get more accurate reading Grey could mean lots of things... it could mean one time it was lean and now its now getting richer.. I dunno never heard of grey.. Just white brown and black... so do that what i said above

[cals400ex]

did you do a plug chop or just check the plug after doing some riding?
this can be a topic that some people disagree on. you have to decide for yourself who is right.

this is what i would do for where i live with the airbox lid on:
elevation is 625 feet
i would put in a 152 in the warmer months and a 155 in the cold months if the only mod is your slip on.

you will loose top speed when going with a jet similar to a 175. i only run a 160 on my built motor in the winter months.

a gray plug doens't mean much too me. i don't go by a nice tan color. i find that to be too rich. i find a jet that will give me a color change on the bend of the plug. i like it to change colors right at the bend. many times it will go from a tanish tinted color to a gray. i like this color change right on the bend of the plug. we need to remember that different fuels will burn differently. good luck

[nikejoe]

I've got the exact same thing! I jetted my quad about a month or so ago, with alot of help from this site. I went with a 155 main and a 40 pilot, with the needle in the stock position. I run an alum airbox with no lid and a K&N. My quad runs absolutely awesome. This weekend is the first time I've really been able to ride it hard. So I put in a new plug and did a plug check. It was grey. Not white, not tan, not brown, not black, GREY! At fist I thought well it must be too lean, it is grey not tan. But I don't think it is???? I don't know, so far I left it! It runs too well not to! If anyone else has any ideas please post them!!! Thanks!
Good luck Willfulone!:p

[MIKE400EX]

The different additives that are put into pump gas don't all burn and yield the same color deposits. Also different oils, especially synthetic & non-synthetic types, leave different colors too. I've noticed a lot of synthetic oils that leave greyish deposits. It's not easy to get a good plug chop reading with pump gas now a days.

[nikejoe]

It's not easy to get a good plug chop reading with pump gas now a days.


I have heard this! But if that is the case, how do you know that you are jetted properly. The plug check is the only way I've ever heard. My quad runs great, but I would like ot know it is right. Not too lean, not too rich!!!! :confused:

[mustang]

Originally posted by MIKE400EX
The different additives that are put into pump gas don't all burn and yield the same color deposits. Also different oils, especially synthetic & non-synthetic types, leave different colors too. I've noticed a lot of synthetic oils that leave greyish deposits. It's not easy to get a good plug chop reading with pump gas now a days.

^^^I AGREE ABOUT THE ADDITIVES^^^

& to awnser the other guys question, The only real way to know 100% you are jetted corectly is with an exhaust gas annylizer

[AndrewRRR]

Where are you reading the plug from? Do a plug chop with a fresh plug after a couple minutes of warming it up and check the smoke ring up high on the ceramic insulation.