help! just bought a 1994 tige and it has problems.

[madmax2015]

so I buy this tige from a guy who replaced the original 454 engine with a chevy 350. well there was a terrible vibration when the motor was running, I mean it seemed like the engine would tear loose from the hull. I had a friend of mine look at it who is good with motors and he discovered that the guy put the original flywheel from the 454 engine on the the 350 motor causing it to be horribly out of balance. after replacing the flywheel with the correct one the motor runs real smooth and everything seemed great, it would rev up past 4000 rpm no problem when out of the water. well I brought it down to the lake and it wont rev past 3000rpm when in the water and it even backfired a little bit when reving it up when it was out of gear.

Is the prop the same on the boats that had the 454 vs the boat that had the 350, or would they have a different prop on the 350 motor since it would be less horse power and less tourque. Also I'm wondering if there would be a different carburetor (maybe the 454 carb if different was put on the 350 motor) I'm just speculating at possible causes of this.

any help would be greatly appreciated.

[Chads972150]

I'm not positive but in almost certain that the carbs would be different the 350 doesn't need as much air and fuel as the 454 so it maybe to big of a carb on it and it's causing it to almost flood it self out ease the throttle up not just hammer it down and see if the rpms come up better if they do you're getting for sure to much fuel you'll need a smaller carb it should be a 600 I believe on the 350

[TeamAllen]

Welcome to the site! Crazy move to switch out motors. I wonder if it was just to save gas or did the other engine have problems?
I would agree the carbs will be different. The prop is a good question and maybe someone will have an answer. If not, I would call acme propellers. They will know.
http://www.acmemarine.com

[chpthril]

Not sure about the backfiring, that sounds like an issue with the ignition secondary. But, i would feel certain that a 454 and 350 would not run the same prop.

[madmax2015]

I will try and find some identifying information on the carb when I get home tomorrow and report back to you guys. I think that is most likely the issue, when I get up to 3000 RPM there is still about 1/3 throttle left and when I push down any farther on the throttle then the motor starts to sputter and the RPMs decrease. Thanks for the link Mike, I'll give them a call tomorrow and see what they say about the prop. Is there usually some ID number on the prop that you can look up to tell what motor it goes with?

[lee]

Is the 350 a marine engine or auto? There is a difference.

[TeamAllen]

Yes, it should have markings of some type. If it's an ACME it will look like this.

[ChrisSnow]

I would say it will certainly be a different prop for different engine power. A prop is generally specced so that at wide open throttle the engine reaches its max rpm under load(normally planning conditions). I know people change them to different ones for personal preference but that's the basic version...

Depending on the carb in question you may need to adjust it's jets if it isn't set up for the engine. Or you could have blocked jets or passages. A lot of carbs have fixed jets so you may need to buy different ones. Altitude also plays a part in the settings.

For example a blocked high jet would mean you simply never get beyond a given rpm.

I had many issues with an old carbed outboard and it was infuriating. This had 3 carbs though and you will only have one to death with!

Messing with carbs is probably beyond most diy people though....

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[madmax2015]

so I looked at the prop and it has 13x13 LH stamped on it. I tried to call ACME but they were closed already (must be east coast time zone) anyway do you guys think that is the right pitch for this boat running a 350 motor?

as for the carb it looks to be a weber and has this number stamped on it 9770 sa 1454 I googled this number but nothing really came up so not sure if this is a carb made for the 350 or the 454. Although from what Chris is saying I will most likely have to get the carb looked at by a professional anyway.

oh and to answer the question about the motor it was from an automobile.

Thanks again for the input, so frustrating not being on the water on these nice summer days.

[lee]

Prop is the right one for a 350. If they did not change the cam out that could be a problem with the engine also.

[ChrisSnow]

Carbs are complicated! So many things can be wrong.

Pull the plugs and get us some photos. The colour and condition can tell you a lot about the fuel mixture.

Have you tried draining the bowl? Possible it's got water in it.

Any mechanic from pre fuel injection days should be able to help..

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