Low rpm wot 70hp

[robert graham]

Preventive maintenance can save most of this...use fuel stabilizer in gas, install a fuel/water seperater, and drain each carb float chamber about twice a year....save all this pain/misery/expense...

[99yam40]

Yep, I know, and thanks. Finding the correct one is the key. And even if I find one, replace it, I don't know if the engines still going to run or not (as their may very well be other issues) and it's been sitting for at least a decade in the weather.


If it was mine (my time is free to me), I would have dug deeper but he wouldn't spend the money with no guarantee..

Yea, when they give you the unit because they do not want to spend money on it,
it is easier to spend some extra time playing with it to see if it is worth putting your time and money into it

[jaredluke]

Ok thanks for the info guys. Fixed the tacho and getting 4800 at wot. Prop size 13.5x15. Still below rpm

[panasonic]

Ok thanks for the info guys. Fixed the tacho and getting 4800 at wot. Prop size 13.5x15. Still below rpm

So the are carbs are clean? The fuel filters are clean? The plugs are good? Please tell us what you have done so far so its not a complete guessing ****.

Do you have a manual for the engine? If not, here is a link to get one: https://www.vansoutboardparts.com/se...a-shop-manuals

The timing advance/retard on this engine is done through the CDI is it not? That maybe off.

Please provide all the information on the data plate found on the engine transom bracket. The gentlemen on here will try to help you but you have to tell us as much information about the engine as possible.

Thanks

[panasonic]

Yea, when they give you the unit because they do not want to spend money on it,
it is easier to spend some extra time playing with it to see if it is worth putting your time and money into it

Scott,

For future reference. I was working on a fellows "old" John Deere Snow blower last year and the carb float had broken apart. So I go to order a float and carb kit...was about $40.00

I plug the carb part number into Mr. Goggle and I see I can get a brand new carb for $19.99 plus shipping...$30.00 total on Amazon or EBay I cant remember now. Got the whole carb in less than a week.

Compared the two and they were identical, put it on and adjusted the mixture by ear and she is running sweet. You can get a lot of these small engine carbs now for dirt cheap.

John Deere wanted almost $200 for a new carb. Worst snow blower I ever laid my hands on though...they should have stuck to tractors.

[zenoahphobic]

Ok thanks for the info guys. Fixed the tacho and getting 4800 at wot. Prop size 13.5x15. Still below rpm

Sorry people here seemed to have gone off on a tangent. 15p is getting low, how heavy is your boat and what speed are you getting?

[TownsendsFJR1300]

Scott,

For future reference. I was working on a fellows "old" John Deere Snow blower last year and the carb float had broken apart. So I go to order a float and carb kit...was about $40.00

I plug the carb part number into Mr. Goggle and I see I can get a brand new carb for $19.99 plus shipping...$30.00 total on Amazon or EBay I cant remember now. Got the whole carb in less than a week.

Compared the two and they were identical, put it on and adjusted the mixture by ear and she is running sweet. You can get a lot of these small engine carbs now for dirt cheap.

John Deere wanted almost $200 for a new carb. Worst snow blower I ever laid my hands on though...they should have stuck to tractors.

Yep, a slight re-rail but, yes, I'm familiar with the E-bay, CHINESE knock off' carbs / parts.

Their NOT OEM and much cheaper ($).

Depending on the part (Yamaha OB's included), some knock off's are ok, some not.

Knock off's for the MC, OFTEN have problems with fit and function.. 99% of the time, I buy OEM, just not worth potential headaches/later issues..


IMO, for the extra $10, for your blower, I would have replaced the parts and kept the OEM carb..

.

[panasonic]

Sorry people here seemed to have gone off on a tangent. 15p is getting low, how heavy is your boat and what speed are you getting?

You correct Z gone off the rails, but at least still on machines.Was waiting for the OP to provide some more information....back to topic at hand. Merry Christmas to ya.

[jaredluke]

Hey guys took off the airbox and looked the carbs. When throttle is in wot position the throttle plates arent exactly horizontal. Could this be the reason why wot cannot ve achieved? I have the service manual but cant find any info on how to adjust

[TownsendsFJR1300]

Hey guys took off the airbox and looked the carbs. When throttle is in wot position the throttle plates arent exactly horizontal.

The throttle plates SHOULD be horizontal @ WOT.

First, make sure the throttle cable from the control box is fully extending. If it isn't, adjust it so it does...

With the throttle cable disconnected, when you move the throttle linkage (at the engine-where the cable attaches), will the butterflys open fully?

If not, disconnect linkages, check each carb butterfly / shaft for correct function.

Then check your linkages for any binding.

In your manual should be a section for "link and sync" , follow that to the letter..