SuzukiSavage.com - Spark plug continues to foul, help

99savage

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Spark plug continues to foul, help
11/03/10 at 17:50:11

My 99 Savage has developed a weird problem over the last few months. Ran great, progressively became hard to start, then wouldn't start at all. I changed the plug and all was great. Then the cycle repeated itself. I'm currently on the 3rd plug and now its "fouled". They are no major visual signs of fouling. I've been using NGK DP7EA-9 gapped at .033; would a different (colder) plug be better?

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verslagen1 YaBB Moderator ModSquad Offline Where there's a will, I want to be in it. Posts: 28890 L.A. California Gender:	Re: Spark plug continues to foul, help Reply #1 - 11/03/10 at 17:54:48 Check your petcock, put the vac line and check for gas.
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Serowbot YaBB Moderator ModSquad Offline OK.... so what's the speed of dark? Posts: 28682 Tucson Az Gender:	Re: Spark plug continues to foul, help Reply #2 - 11/03/10 at 18:04:15 Test yer' petcock... here's how... http://suzukisavage.com/cgi-bin/YaBB.pl?num=1251932429 ... add another Suzuki petcock to the heap... I'm thinking of starting a "Creative uses for your old broken Suzuki petcock" thread...
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99savage

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Re: Spark plug continues to foul, help
Reply #3 - 11/03/10 at 18:07:13

verslagen1 wrote on 11/03/10 at 17:54:48:

Check your petcock, put the vac line and check for gas.

Thanks, I did that and everything checked okay with the vacuum line (no gas even if I sucked on it). Pulled the supply line and had steady flow when on prime, no flow otherwise. Also checked for fuel in bowl and it drained and refilled after reconnecting the supply line.

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Serowbot YaBB Moderator ModSquad Offline OK.... so what's the speed of dark? Posts: 28682 Tucson Az Gender:	Re: Spark plug continues to foul, help Reply #4 - 11/03/10 at 18:12:21 In that case,... could you be jetted too rich?... is it stock jetting?... air filter clean?... ... or you may have a sticky slide in the carb....
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99savage

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Re: Spark plug continues to foul, help
Reply #5 - 11/03/10 at 18:14:02

Serowbot wrote on 11/03/10 at 18:04:15:

Test yer' petcock...
here's how...
http://suzukisavage.com/cgi-bin/YaBB.pl?num=1251932429

... add another Suzuki petcock to the heap...
I'm thinking of starting a "Creative uses for your old broken Suzuki petcock" thread... Huh

I'll be swapping out the petcock this weekend just to be safe, but I'm still confused how a bad petcock would ruin a spark plug in such a few weeks over the period of a few hundred miles.

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99savage Junior Member Offline SuzukiSavage.com Rocks! Posts: 51 Strawberry Plains, TN Gender:	Re: Spark plug continues to foul, help Reply #6 - 11/03/10 at 18:17:09 Serowbot wrote on 11/03/10 at 18:12:21: In that case,... could you be jetted too rich?... is it stock jetting?... air filter clean?... ... or you may have a sticky slide in the carb.... Stock jetting, no mods, new air filter (even checked for gas in air box for flooding, none there), fresh fuel etc.
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verslagen1 YaBB Moderator ModSquad Offline Where there's a will, I want to be in it. Posts: 28890 L.A. California Gender:	Re: Spark plug continues to foul, help Reply #7 - 11/03/10 at 18:26:05 well that covers the usual issues... I'd drop the bowl and take a look at the jets. sometimes the jet will back out if loose. or it can act rich if the washer under the main jet was left off. next, how many turns out is your idle jet? more than 3 turns and it can vibe out.
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Serowbot

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OK.... so what's the
speed of dark?

Posts: 28682
Tucson Az
Gender: male

Re: Spark plug continues to foul, help
Reply #8 - 11/03/10 at 18:32:40

99savage wrote on 11/03/10 at 18:14:02:

Serowbot wrote on 11/03/10 at 18:04:15:

Test yer' petcock...
here's how...
http://suzukisavage.com/cgi-bin/YaBB.pl?num=1251932429

... add another Suzuki petcock to the heap...
I'm thinking of starting a "Creative uses for your old broken Suzuki petcock" thread... Huh

I'll be swapping out the petcock this weekend just to be safe, but I'm still confused how a bad petcock would ruin a spark plug in such a few weeks over the period of a few hundred miles.

If the diaphragm is leaking in the petcock, it will leak extra fuel down the vacuum line and inject it directly into the intake... this makes a variable rich condition that will definitely foul plugs like crazy...
May not be your problem, as you say you got no fuel from the vac line when you sucked on it.
It often is the problem though...

The other thing,.. as I said,... might be the carb slide getting sticky...

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...

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99savage

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Re: Spark plug continues to foul, help
Reply #9 - 11/03/10 at 18:47:33

Serowbot wrote on 11/03/10 at 18:32:40:

99savage wrote on 11/03/10 at 18:14:02:

Serowbot wrote on 11/03/10 at 18:04:15:

Test yer' petcock...
here's how...
http://suzukisavage.com/cgi-bin/YaBB.pl?num=1251932429

... add another Suzuki petcock to the heap...
I'm thinking of starting a "Creative uses for your old broken Suzuki petcock" thread... Huh

I'll be swapping out the petcock this weekend just to be safe, but I'm still confused how a bad petcock would ruin a spark plug in such a few weeks over the period of a few hundred miles.

If the diaphragm is leaking in the petcock, it will leak extra fuel down the vacuum line and inject it directly into the intake... this makes a variable rich condition that will definitely foul plugs like crazy...
May not be your problem, as you say you got no fuel from the vac line when you sucked on it.
It often is the problem though...

The other thing,.. as I said,... might be the carb slide getting sticky...

I had the carb off and cleaned it after the second plug and everything seemed fine.

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verslagen1 YaBB Moderator ModSquad Offline Where there's a will, I want to be in it. Posts: 28890 L.A. California Gender:	Re: Spark plug continues to foul, help Reply #10 - 11/03/10 at 19:07:09 99savage wrote on 11/03/10 at 18:47:33: I had the carb off and cleaned it after the second plug and everything seemed fine. Did you do any work on it prior to it fouling out?
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99savage

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Re: Spark plug continues to foul, help
Reply #11 - 11/03/10 at 19:10:44

verslagen1 wrote on 11/03/10 at 18:26:05:

well that covers the usual issues...
I'd drop the bowl and take a look at the jets.
sometimes the jet will back out if loose.
or it can act rich if the washer under the main jet was left off.

next, how many turns out is your idle jet?
more than 3 turns and it can vibe out.

Idle jet is only 1 turn out (I adjusted according to the directions on this forum, Lancer's I believe). Is it possible that it is a coil problem (long shot I know) or poorly adjusted valves (runs great on fresh plug however)? Do you suggest switching to a colder plug when I swap the petcock?

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99savage

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Re: Spark plug continues to foul, help
Reply #12 - 11/03/10 at 19:12:46

verslagen1 wrote on 11/03/10 at 19:07:09:

99savage wrote on 11/03/10 at 18:47:33:

I had the carb off and cleaned it after the second plug and everything seemed fine.

Did you do any work on it prior to it fouling out?

Nothing at all. After fouling the first 2 plugs, that's when I pulled the carb. That and the fact that I had a stuck float. Made no adjustments just cleaning, checking, and reinstalling. Seemed fine again for a while, and then it ran the same course.

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verslagen1 YaBB Moderator ModSquad Offline Where there's a will, I want to be in it. Posts: 28890 L.A. California Gender:	Re: Spark plug continues to foul, help Reply #13 - 11/03/10 at 19:15:29 if it's fouling out, then's there's a reason. If you had access to a spare coil or CDI, I'd swap them. But due the easy stuff 1st. How's your battery? low voltage can make a sour plug. check all the grounds.
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99savage

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Re: Spark plug continues to foul, help
Reply #14 - 11/03/10 at 19:23:28

verslagen1 wrote on 11/03/10 at 19:15:29:

if it's fouling out, then's there's a reason.
If you had access to a spare coil or CDI, I'd swap them.

But due the easy stuff 1st.
How's your battery? low voltage can make a sour plug.
check all the grounds.

New AGM Big Crank fully charged. Cranks very strong just won't fire.

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