newly swapped 62T running funny

B

beenen

Location
Fort Wayne
swapped in a 62T to replace my 650 in my SN. wouldn't fire at first unless I poured gas down the carbs. It runs fine until about half throttle--I copied and pasted below my post from another website--

It did fire when I poured gas down the carbs. it idles fine out of water. I dipped it in the river while on the trailer and it idles fine, 1/4 throttle fine, but half throttle is starts sputtering and full throttle it dies.

I ended up replacing the diaphragms with new ones since the old ones had crusty crap around the outsides. I cleaned the fuel filter and also blew out the jets.

I just dipped it back in the water today and it still has problems but they seemed to improve.

dipped in the water and it idles perfectly, 1/4 is great but half throttle is dips low in RPMs like its about to stall and full throttle does the same thing but after about 5 seconds of "low RPMs" it finally revs up. I only got to do it twice because it started slipping off the trailer lol.

any ideas what to do next? the 650 engine I had running in there ran perfectly so if it's a fuel related problem I think it has to do with the new 62T. it also has brand new spark plugs
 
Quinc

Quinc

Buy a Superjet
Location
California
Try opening the high screws a turn and see if it gets better. If it gets better open them some more. If it gets worse turn them "in" a half turn at a time see if it gets better.
 
B

beenen

Location
Fort Wayne
no I have not rejet it. I was just thinking this last night since possibly the wave raider exhaust is bigger than my stock super jet exhaust (61X manifold port matched)

not pressured tested it either. guy I bought it from said it was 150 and ran good before it sat all last year
 
B

beenen

Location
Fort Wayne
jetx said:
Lots of missing Info here...what's your entire setup? Carbs, pipe, prop, current jetting, etc?

Need a bigger picture to help narrow it down
Click to expand...


bone stock 62T/62T

61X head, 61X exhaust manifold (port matched), stock super jet exhaust set up.

the 650 I had just pulled out ran great. everything on the hull is stock as well
 
jetx

jetx

Location
Midland, Ontario, Canada
Believe raider jetting and superjet jetting are different...so if you haven't rejet id start there.

Stock superjet should be
70/130 with 1.5 n/s and 115 g spring

Also if your running a stock impeller I'd consider upgrading as soon as you can as there is a lot to be gained with a good stainless vs the stock alum.
 
mthomps

mthomps

Location
Cleveland
Remember you can have a perfect compression but an air leak in the crank case. good compression does not mean there is no air leak. An air leak is going to happen at the base gasket or below. All you need is 2 pieces of rubber to block off the carb and the exhaust and a bike tire pump with a gauge to pump it up to no more than 10 psi.

This sounds carb related especially since air leaks will cause lean conditions and your plugs look very rich. I'd look through those carbs and inspect everything. Your jets could be worn, n/s could be stuck or grooved, inspect internal fuel filter, etc. The carb could be set up wrong or absolutely anything honestly.

Check the valve connected to your gas tank and make sure it blows in and not out only. Inspect fuel line for leaks or lose fittings, etc. Rule out stuff based on how much it costs to check lol. You'll nail it eventually.
 
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B

beenen

Location
Fort Wayne
thank you for all of the info!!!

I think I will start by ordering stock super jet pilots/main and possibly the 115 g spring. then retune the carbs (wish me luck..it'll be my first time tuning lol)

I will also check that valve, thomps
 
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