Theres nothing fishy about it. The pictures speak for themselves. The piston isnt going to melt on the opposite side as the exhaust. The only foreign object in there is the dowel pin for aligning rings and it smashed the hell out of it. Its still stuck in the piston.
- Location
- Jersey
if it was a modded motor on set of stock carbs from a stock boat with stock jets then it seems that the boat had a serious case of detonation
not a rocket scientist but i have leaned out a motor or two before
Mouthfulloflake
ISJWTA member #2
- Location
- NW Arkansas
mixing gas at 32:1 leans out the fuel/air mix too right?
and its hard to check plugs when you run for 2K for a few minutes, then 4K for a few minutes, as you said in an earlier post.
and its hard to check plugs when you run for 2K for a few minutes, then 4K for a few minutes, as you said in an earlier post.
- Location
- Jersey
no it makes the mixture more rich.
32:1
40:1
50:1
100:1
in order from richest to leaneast
ToddW
Web GuY
- Location
- Folsom Lake - CA
IMHO it's up to seller if he decides to be nice to the buyer and pay for some of the repairs. He not us is the only one who really new the state of the engine before selling it to you.
If he's a good guy which it sounds like and is telling the truth then if I were him I wouldn't pay because he sold a working engine and thinks you messed it up.
Now, on the other hand you think he sold you a bad engine and want him to repair it... you see no one wins. If he gives you 50% then he's agreeing to have sold you a bad engine.
It's a tricky situation but as a buyer I don't think you can demand something from a seller of a used part or even act like they owe you.
Last summer my father sold a Sea Doo the buyer tested it on the water for a while was happy and bought it the next day. All the while my father said it seemed to be running slower than normal but the buyer insisted it was fast enough for him and still wanted it. Well, a week later the buyer calls it wont run well anymore and my father chips down $250 or so (i forget but was well over 200) to help pay for a carb rebuild or whatever he was told it needed. Now, if it were me I would have said to bad you bought it that way I warned you I was going to fix but you wanted anyway. Some people may call me a bad seller for that ??? It really depends on the situation, and really only the buyer and seller know the full details. Oh, and guess what, a week later the guy had re-posted the sea-doo for sale anyway, it was now "to fast" for him and he sold it for more than my father sold it for.
(I'm not bashing reselling and making money here, but the fact that it was bad that he came back to my father to get $ to fix it then turned around and made a profit on it.)
If he's a good guy which it sounds like and is telling the truth then if I were him I wouldn't pay because he sold a working engine and thinks you messed it up.
Now, on the other hand you think he sold you a bad engine and want him to repair it... you see no one wins. If he gives you 50% then he's agreeing to have sold you a bad engine.
It's a tricky situation but as a buyer I don't think you can demand something from a seller of a used part or even act like they owe you.
Last summer my father sold a Sea Doo the buyer tested it on the water for a while was happy and bought it the next day. All the while my father said it seemed to be running slower than normal but the buyer insisted it was fast enough for him and still wanted it. Well, a week later the buyer calls it wont run well anymore and my father chips down $250 or so (i forget but was well over 200) to help pay for a carb rebuild or whatever he was told it needed. Now, if it were me I would have said to bad you bought it that way I warned you I was going to fix but you wanted anyway. Some people may call me a bad seller for that ??? It really depends on the situation, and really only the buyer and seller know the full details. Oh, and guess what, a week later the guy had re-posted the sea-doo for sale anyway, it was now "to fast" for him and he sold it for more than my father sold it for.
(I'm not bashing reselling and making money here, but the fact that it was bad that he came back to my father to get $ to fix it then turned around and made a profit on it.)
the carbs were tuned right. the plugs were a light brown. the motor wasnt moded. He said the ports were "cleaned up". it snagged a ring from poor chamfering however you want to spin it. It wasnt detonation lol.
Mouthfulloflake
ISJWTA member #2
- Location
- NW Arkansas
I agree. There is very little to absolutely no chamfer on any of those ports.
It looks as if it was bored and someone didn't chamfer it - what little there is, is residual chamfer from the previous bore.
This is what I am seeing on those ports - I don't know if that's what cause damage
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Absolutely incorrect. You got it backwards.
Per given volume, 100:1 has the most volume of gas, versus 32:1 which has the least amount of gas.
The Penguin
triple secret probation
- Location
- down by the river
:haha: :haha: :haha:
32:1 means 32 parts gas to 1 part oil.
100:1 means 100 parts gas to 1 part oil.
100:1 means boom, 32:1 is typical.
100:1 means 100 parts gas to 1 part oil.
100:1 means boom, 32:1 is typical.
Mouthfulloflake
ISJWTA member #2
- Location
- NW Arkansas
50:1 is typical in a water craft.
IN fact your 750ss there, with its factory oil injection goes anywhere from 32:1-200:1 depending on engine RPM.
also, I wasnt talking about the fuel to oil ratio.
I was talking the fuel to AIR ratio.
32:1 premix thru a given jet into an engine, is LEANER ( fuel to air) than
50:1 premix thru the same jet/engine.
the oil takes the place of the fuel in the fuel to air ratio.
there are a bunch of dumbasses on this site!
:biggrin:
IN fact your 750ss there, with its factory oil injection goes anywhere from 32:1-200:1 depending on engine RPM.
also, I wasnt talking about the fuel to oil ratio.
I was talking the fuel to AIR ratio.
32:1 premix thru a given jet into an engine, is LEANER ( fuel to air) than
50:1 premix thru the same jet/engine.
the oil takes the place of the fuel in the fuel to air ratio.
there are a bunch of dumbasses on this site!
:biggrin:
- Location
- Rincon Beach
OK folks, that is what a piston and cylinder look like from the effects of Detonation. the ring colapsing and and catching the port was a side effect (in this case) as a hole was burned thru the piston,
also the exhaust port on that cylinder has NOT been widened, as such very little port chamfer is required (although I prefer more)
this motor failed in my opinion from detonation, could have been lean on the carbs, air leak , too low an octane fuel, old fuel ect.
Db
also the exhaust port on that cylinder has NOT been widened, as such very little port chamfer is required (although I prefer more)
this motor failed in my opinion from detonation, could have been lean on the carbs, air leak , too low an octane fuel, old fuel ect.
Db
W
wydopen
Guest
how do you know if the carbs were tuned right when you rode it at 2k for a few min?
AlbanyMotorsports
Cru is Rad
- Location
- Chicago
Endo
Non-tree hugger
- Location
- Northeastern Indiana
Thank you Mouth!! I really didn't want to say it!
It was not detonation. If you had this sitting in your hand youd see that too. I didnt say i only rode at 2k rpms. I started with that. the engine had the proper mixture of fuel to air, oil to gas, proper octane. I was running 93 in it with 167ish psi. I think its clear that it snagged a ring ran on teh cylinder wall for a lil while, Melted itself, snagged teh dowel pin, ripped a chunk out, wore alil more and then was done. No detonation. The top of the piston is nto melted. It is restricted to that area.
- Location
- Melbourne, FL
does riding at 2k rpms for 2 minutes tell you anything by looking at the plugs. I wouldn't think you could get a good read without going all the way through the rpm range to get low and high speed jet performance. Just a question here for my personal knowledge bank.
going slow will give you an idea about the low speed jets, You need to take more into account like hesitation and loading up and such. Going at 4-6k will give you an idea of the high speed jets. I wouldnt go past 6k after putting a motor together for atleast an hour.