SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: challenger on February 15, 2010, 05:27:54 PM
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OK so the shtt goes on. i had a popping this weekend at WOT but would go away as soon as i let up so i pulled the plugs my gaps are all over the place one electrode was touching and the rest are from 5k to 25k and they were 60k going in what the hell happened
i have 10 trips on them 460
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Plugs too long for pistons? I'm not 100% sure but I think there may be 2 different lengths available for spark plugs. I know you could use copper gaskets to decrease the amount the plug goes in.
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I'd be guessing an extreme lean condition, given the popping (had that recently). Extreme lean will cause serious detonation and can easily mess up the plugs that way under decent compression. Read your plugs, what color were they? If there was a contact or interference issue, woulda been much worse than that I would think.
Just a guess, but from the sequence of events..... ;)
Ray
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I'd be guessing an extreme lean condition, given the popping (had that recently). Extreme lean will cause serious detonation and can easily mess up the plugs that way under decent compression. Read your plugs, what color were they? If there was a contact or interference issue, woulda been much worse than that I would think.
Just a guess, but from the sequence of events..... ;)
Ray
chas ray i thought that to fixed the gap and ran it 15 min did comp test 150 high 145 low all around and the gap is still ok...... so whats next guys? thanks for the help!
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A lean pop or detonation will destroy gaps too..you should verify the plug reach with the heads you are using...How sure are you that the timing is not "wandering"? seen it a time or two before.
GT
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A lean pop or detonation will destroy gaps too..you should verify the plug reach with the heads you are using...How sure are you that the timing is not "wandering"? seen it a time or two before.
GT
GT how do i check that... ita all MSD 6AL box blaster 2 coil
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GT how do i check that... ita all MSD 6AL box blaster 2 coil
The easiest way to check it by yourself is to retard the timing a few degrees or see if someone near you has an old Sun distributor machine to bench test it...Retarding the timing will either make it worse or better, If worse, I would say you have an advance problem, if better, look at the carburetion a little closer... :thumbup:
If not by yourself, bring a timing light with you and have your buddy drive the boat at WOT while it's popping and farting and see what the timing is doing...Be careful though, good water is a necessity (no roll bar boats in the immediate hood.. :screwy: ).
You should be able to do this while tied to something very stationary (like a truck or something) just run it ball out and see if you can duplicate it. :thumbup: just don't do like me and drag the dock across the lake :banghead:
GT
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Mine was all carbeuration. (sp) Just food for thought. Timing was spot on. At high RPM, with compression, makes sense. Funny thing with mine was, one of the carbs ran the boat better than two. Same carbs! ran one for awhile, then the other. Together on a new T/R, lean, go figure. Didn't have the extreme of the spark plugs, but did hear popping (Actually, Flytime heard it too while in the boat).
Good luck with yours!
Ray
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What heads are you running. How much compressing originally. two things it could be.
1 is your voltage is was low, under 14.5 the msd will do this, and act funny especially at low rpm. the msd has to have 14.5 or it will act funny. mine did the same thing my last trip. my alt crapped out on me. I have efi. When I first ran the boat with charged bats it ran perfect on the low end n idle, then when the bats ran down it did the same thing started popping and sputtering at idle and low rpm. didn't touch the tune in between. charged the bat and then back to normal. run a volt meter while its running and check the voltage. if its under 14.5 that's your prob.
2 first check the end of the plugs for a tiny scratch or marking. If there is you need to run a non extended reach plug or shorter plug. the piston is slapping the gap shut. This also has happened to me last season. Mine did it on 5 or 6 plugs out of 8. took me forever to figure out. I RUN A PLUG FROM ZEX. There great plugs. I have some alum race heads, wish someone would have filled me in b 4 this happened. It ate up my cap and rotor a bit because of this. think it got hot.
If its doing it on the mid to top end then you may need to jet up but I would still check the above. I could be wrong. The plugs Im running are triple fire premium plugs but not to pricey. like 40$. part number 82003-8. for bbc. they work great and you don't have to run spray to use em.
http://www.zex.com/
Let us know what you find out I'm very interested
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what does engine doc say ???
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Sounds to me like tuning issues.
1.If the plugs hit pistons you'd really have problems.
2. Look at timing/carburetion.
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My boat was doing the same thing for the longest time, pops and gaps all over. I couldn't figure it out. I am running a ZZ502 that had an 850 dbl pumper on it. Tried a few different things. Timing was tits. Put on a dominator and wahla. Popping went away. All I needed was about bigger stream. Story of my life. I say add more fuel.
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it keeps getting shtter and shtter.... i well have to get back to this next week i f***** up my starter doing the compression test
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it keeps getting shtter and shtter.... i well have to get back to this next week i f***** up my starter doing the compression test
ok it was just a bad installer ME :banghead: dam i ran them with 045 and it =ran hard and no popping pulled the plugs after today and they look good :thumbup:
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i was going to say i get the same thing from here and there, and what i have found is some nice pretty stuff in the needle and seat...causing my lean condition! so while your at it check out your needle and seat
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ummm...im not a moderator ::) but this is in a classifieds section....just sayin
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ummm...im not a moderator ::) but this is in a classifieds section....just sayin
O i was tring to sell it if it was focked up >:D
j/k
i was looking for parts to fix it
i did find a jegs hook up out of all this... for anybody looking for jegs shit i know some one