Dropped cylinder test

[DEL1]

Assuming every thing is correct with set up on my engine
Link and sync and correct prop 10 3/8x 14p. Is there a test I can
perform to figure out if I have a cylinder dropping out.
02 merc. 40 hp 2 cyl 2 str on 16 ft lowe. Only getting 3500 Rpms will not plane

 

[MH Hawker]

Re: Dropped cylinder test

Run a compression test on all cylinders.

 

[DEL1]

Re: Dropped cylinder test

120 both cyl.

 

[gm280]

Re: Dropped cylinder test

Not knowing for certain, but I would expect that engine to trun nearer to 5000 RPMs when it is working properly. Is the prop a factory setup or did someone change it along the way? !4 pitch seems a little strong for that setup. If it was changed, I'd drop back to an 11P or 12P and see how that works.

 

[DEL1]

Re: Dropped cylinder test

Not factory. Had 89 rude 40 hp2str on it before. Would do 35 mph.
This engine feels like it is a 20 hp.
From reading other post. Same set up runs just fine. Was told would
it would only raise rpm by 600 Rpms max by changing pitch.

 

[gm280]

Re: Dropped cylinder test

Not factory. Had 89 rude 40 hp2str on it before. Would do 35 mph.
This engine feels like it is a 20 hp.
From reading other post. Same set up runs just fine. Was told would
it would only raise rpm by 600 Rpms max by changing pitch.

Are you sure your enigne is indeed a 40 HP? Post the make, year, model and serial numbers on here and we will see...

 

[MH Hawker]

Re: Dropped cylinder test

120 should be just fine. Is this a new problem or it one that's been there awhile. It may be fuel related if its just coming out of winter storage. And if so how do you maintain the fuel for storage.


What type of hull are you using, I am far from being one of the prop guys but it makes a huge difference what pitch is used per hull type and a prop is used to limit the max RPM`S. A 9,11 and 13 is often used on a pontoon for a load type of prop. So a 14 p may be fine, but its one thing to look at.

If this just happened and it was fine before that sort of rules out the prop

 

[DEL1]

Re: Dropped cylinder test

2002 40ELPT0 Ser OT571640 MERCURY

 

[DEL1]

Re: Dropped cylinder test

It's a 16ft mod v aluminum new tank new fuel. Had a voltage regulator replaced. Carb rebuilt new plugs. E
Engine has been serviced. But they don't do it under load. That's why I want to know if there is a test I
Can perform that will tell me if I am getting a spark while wot.
Can I pull a plug wire off whole its running without doing Amy damage and getting shocked. To see if there is
an rpm change ?

 

[carholme]

Re: Dropped cylinder test

That s/n comes up as:

MERCURY - ( 40 H.P. (2002 ))
Serial No: 0T571640 Model No: 1041412ZD

Parts List for Model 1041412ZD:

30/40 (2 CYLINDER) 2-STROKE - Mercury, Mercruiser, Force, etc. Parts Lookup

Service Manual P/N: 826148R03

If you don't have a manual, send me a PM with an email address and I will send you a copy.

Gerry

 

[DEL1]

Re: Dropped cylinder test

Thanks for info. I have a manual thanks.