$100 Reward, Yamaha 250 1997 #5 & #6 only, plugs corrode

[soundsfishy]

3 Years ago found # 6 cylinder spark plug corroding (looked like a lean condition). Replaced Plug, Fuel Injector, wire/coil assy., Computer, no luck.<br />Dealer replaced head & spacer this spring. Now the # 6 and # 5 spark plugs are burning up. This corrosion/burn (the ground strap on plug eventually disappears) takes about 30 hours to occur....Repace plugs & OK for 30 hours again...<br />I'm at wits end.....I believe that salt water is somehow backing up into the cylinders?...again it started for 2 years with just # 6 that's the first plug up from the waterline...# 5 is the next Plug up on the crank.........<br />I'll send a $100 check to anyone with the fix & I'm serious !!...Thanks !!!

 

[vidar]

Re: $100 Reward, Yamaha 250 1997 #5 & #6 only, plugs corrode

hi!if you got saltwater in cylinder the cyinder voud also be dull/corroded and piston completly clean....if so check exhaust cower for leaks..just a thougth...i knows its a nightmare...

 

[The Marine Doctor]

Re: $100 Reward, Yamaha 250 1997 #5 & #6 only, plugs corrode

Low Fuel rail pressure.<br /><br />TMD

 

[soundsfishy]

Re: $100 Reward, Yamaha 250 1997 #5 & #6 only, plugs corrode

Regarding saltwater intrusion...the cross hatch pattern is gone at top of bore , but other wise compression is perfect & the leak is so small that top's of pistons are slightly oiled...not blown clean like a major water intrusion. What is the exhaust cover you refer to? can you explain a little more......<br />If that's it....I'll get an address where I can send the check...

 

[soundsfishy]

Re: $100 Reward, Yamaha 250 1997 #5 & #6 only, plugs corrode

With regard to low fuel rail pressure....will this cause the problem to move up the spark plug line?..From # 6 ....now to # 6 & #5 ?<br /><br />I replaced the fuel injector on # 6 & it had zero affect....what do I do to correct low fuel rail pressure?....

 

[vidar]

Re: $100 Reward, Yamaha 250 1997 #5 & #6 only, plugs corrode

if this is a v6 engine you shoud have a plate between sylinder rows..this is a plate w/cooling channels and some gaskets..i had a tiny leak in a motor i fixed..it had just a pinhole.. hard to see.had to cleen very good.. that made just a "fog" that enterd cylinder 3+4 on that one...

 

[soundsfishy]

Re: $100 Reward, Yamaha 250 1997 #5 & #6 only, plugs corrode

Thanks WoMax...if that plate is it.....I'll let you know & get a check out to you....<br />Thanks again..we'll give it a go....<br />It is a V6 250 hp Yamaha 1997

 

[soundsfishy]

Re: $100 Reward, Yamaha 250 1997 #5 & #6 only, plugs corrode

Oh well....sorry guys for thanks for the tips...it looks like the block is bad (**** )!!<br />With my kid in college....this is gonna be painful