Help with 717 bogging

[cyaman37]

I need more help please,just reinstaled the engine that was recently rebuilt by SES the first time i installed it it ran great during break in untill the brass gear failed so was sent back and he took care of it not it is back in and aligned it runs
great at idle and topend but when i anvance the thotle slowly it losses rpms and the engine will die if i jam the throtle up to about half it takes off fine. Carbs are set at 1 3/4 on low and 1 1/4 high. Was told the carbs had been rebuilt not long befor i bought the boat and i know the filter in the carb is clean. So im not sure what to look for im thinking it is lean on low end but im not sure. Thank you in advance for any help for can give.


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[bellski]

Hope someone can help I'm having almost the same problem

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[bellski]

I've been told its the fuel pump going bad im new so that probly won't help you much

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[cyaman37]

That is a possibility but I would think if it was the fuel pump it would run lean at wot but I guess that would be an easy thing to check I could swap the fuel pump to the other engine and see what happens.


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[bellski]

Yea... Mine boggs down at top end so might be something different

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[cyaman37]

Yes if yours is bogging at top end that could be fuel pump or dirty filter/carb.


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[bellski]

Yea mines at the shop now. .. rebuilt carb last week and it didn't help at all... Hopefully fuel pump... compression is 150

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[bellski]

But this post is for yours didn't mean to intrude.... Just thought u may want to try the fuel pump

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[cyaman37]

Thank you for the input. I didn't even think of the fuel pump being my problem but it could be,anything is possible. I'll swap my fuel pumps and see what happens it can't hurt and it's a easy swap.


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[killer454]

I have a 1995 speedster-I have the 657x engines and I looked at my high and low speed jet settings on mine and it says
low-all the way in till resistance felt then back off 1-1.5 turns out
high-0-from what I read this could be .25 out

could your high speed jet be causing a real rich bog hitting in the low and high speed circuit upon throttle up

your engines not to different from mine right-im no expert but when I dial my jets in on mine im going to put the high at 0 and go out at .25 incriments I read somewhere that they run great at 0 on the high and if you are at 1.25 could that be making a real rich carb setting.i also read that the low and high both function at the same time for a period of time then the low stops and the high takes over high 1.25 sounds rich to me and a bog

 

[cyaman37]

Well I don't think the high speed needle would have any effect on the low end mine runs good at mid to full throttle It's just off idle that it bogs and I'm thinking it's a lean bog Both of my engines are set the same and the other one runs great so I don't think it is my carb settings. I know the high should be set at 0 but they have been set this way since I got the boat but I will probably set the high needle to 0 which is the factory spec I would rather run rich than lean


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[killer454]

yes running rich is better than lean-I don't want to see you toast your engine im no expert at all so please becarefull
are you plugs real wet? whats the plugs look like from one cylinder to the other same?
I have seen people miss align the carb base gaskets-are you sure one didn't slip away from the intake -they are kinda hard to see when installing and one side can slip down and you think you got them right the bolts go fine but then upon removal you will see you missed a bolt hole and you had a air leak causeing a lean condition on one cylinder you may check this.

if you want to talk and have free long distance 660 388 5158 Philip
im no expert but have rebuilt 4 2-strokes 3-skis 1-banshee 350 no problems what so ever andnow my speedster and next 2001 xlt 1200 yamaha

 

[jhjesse]

No external fuel pumps on your ski. Your problem is carb related. I personally would not trust that the carbs were rebuilt. I would thoroughly go through the carbs and make sure everything is clean and in proper working order. I would also replace the needles and seats in the carbs as they are probably 17 yrs. old. (Use only genuine Mikuni parts)
Additionally I would clean or just replace the fuel selector valves and replace the O ring on the fuel filter/water separator to insure you are getting fuel to the carbs.

After you try it out pull the plugs and see if they are chocolate brown and slightly wet.

If you are still having trouble and are sure it is not fuel related, put a volt meter on the battery and run it while looking at the meter. Should be reading about approx. 13.5vdc.
If the voltage is over 14vdc, or under 13vdc, then your rectifier is bad and they will make these engines do funny things.

 

[cyaman37]

Yes I do have external fuel pumps on my boat


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[jhjesse]

Oh...I have never seen a 717 with external fuel pumps. Doesn't mean anything, just means I have never seen one. I still think your problem is carb related, otherwise it would bog at WOT.

Post your year and model boat so that others can help.

 

[cyaman37]

I believe you are correct I think it is carb related also and think I already said that it would run lean at wot if it were my fuel pump but that is a easy check to rule out the pump by just swapping fuel pumps between the motors.


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