volvo penta 290 dp spark plugs came loose

ericv26

Seaman Apprentice
Joined
Jun 21, 2013
Messages
43
hey guys. my boat is a 26 foot stamas hardtop with a 1999 5.7 volvo penta. I bought the boat abot 4 months ago. the engine is considered a votec. while doind routine tune up I found the previous owner install incorrect plugs. He has autolite 26 plugs in it which ar for earlier sbc engines and have only half of the threads they should have. after doing research found that autolite 605 plugs are for the vortec engine. I installed the plugs and reset timing. boat ran well with new plugs and actually piced up mph.started having power issues and found defective fuel pump(only 2 psi pressure) replaced pump and went out on sunday boat began to run rough and on way back in died.(luckilly my buddy was out with me and pulled me in). upon diag I found that 5 plugs came loose and burned up electrodes.I am a auto tech by trade and have intalled alot of plugs and never had one come loose. any thoughts???? thinking that maybe some carbon is in threads from wrong plugs not letting new ones seat all the way. goind to chase holes tonight.. any help would be great. thanks eric
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,130
Re: volvo penta 290 dp spark plugs came loose

hey guys. my boat is a 26 foot stamas hardtop with a 1999 5.7 volvo penta. I bought the boat abot 4 months ago. the engine is considered a votec. while doind routine tune up I found the previous owner install incorrect plugs. He has autolite 26 plugs in it which ar for earlier sbc engines and have only half of the threads they should have. after doing research found that autolite 605 plugs are for the vortec engine. I installed the plugs and reset timing. boat ran well with new plugs and actually piced up mph.started having power issues and found defective fuel pump(only 2 psi pressure) replaced pump and went out on sunday boat began to run rough and on way back in died.(luckilly my buddy was out with me and pulled me in). upon diag I found that 5 plugs came loose and burned up electrodes.I am a auto tech by trade and have intalled alot of plugs and never had one come loose. any thoughts???? thinking that maybe some carbon is in threads from wrong plugs not letting new ones seat all the way. goind to chase holes tonight.. any help would be great. thanks eric

Ayuh,.... As for their loosenin' up, yer probably Right, in that they were never seated,...

As for the burnt up electrodes,...
It's runnin' Lean, that's a sign of Detonation,...

Btw,.... I run only AC Delcos in Chevy's, MR43TLS are the plugs for yer motor,...
 

ericv26

Seaman Apprentice
Joined
Jun 21, 2013
Messages
43
Re: volvo penta 290 dp spark plugs came loose

thanks for the reply. where did you find info on plugs. I crossed the number it came up to the plugs that were in it which r short thread peanut plug used on early small blocks. mine has the vortec heads and all info i find says to use the long thread peanut plug which is the 605 auto light. I even checked what plugs this engine used in cars and trucks and came up with the 605. I also use ac delco stuff but I do like auto lite plugs. have used them for years in my chevelle and have never had an issue.
 
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