What did the dealer mean..tap to start?

[jkust]

Hi all, I just bought 2003 Chaparral with 50 hours on the meter. It has the Mercruiser 190 hp carb engine. The guy I bought it from explained that the dealer told him that at times these Mercs may not start and to tap somewhere on the top of the engine. Apparently this tapping is supposed to do something with the fuel to break somesort of bubble loose. This non-starting issue happened one time, the old owner did the tapping and it started. Any ideas where you are supposed to tap and what this accomplishes? I do not have the boat yet as it gets delivered on Friday and this will be my first I/O.

Does anyone know if the 2003 has Turn Key Starting (TKS)?

Thanks

 

[45Auto]

Re: What did the dealer mean..tap to start?

Pretty common to tap on the top or side of the carbureter if you've got a sticking float. Shouldn't be any need to tap anything if the boat is in good condition. Did you sea-trial the boat before you bought it? Get the owner to show you where he's tapping.

 

[Fishermark]

Re: What did the dealer mean..tap to start?

If you are having to tap anything like that - it needs to be fixed. While tapping a carb might free up a stuck float or needle valve, it would only serve as a helpful diagnostic aid to identify a problem. Certainly not something you should have to do on a regular basis.

 

[jkust]

Re: What did the dealer mean..tap to start?

If you are having to tap anything like that - it needs to be fixed. While tapping a carb might free up a stuck float or needle valve, it would only serve as a helpful diagnostic aid to identify a problem. Certainly not something you should have to do on a regular basis.

This little bit of advice the dealer gave was part of the walk through upon taking delivery when new. The owner apparantly only had to actually do it one time. I am not sure what to believe since I hear these carb engines can be finicky from the start when new. That's I why I looked so hard for an MPI
v6 but was nearly impossible to find a used one not at a dealer in a small boat. I am really suprised that carbs have been used at all in the last 15 years. A dealer told me that the Brunsick company drives the industry to still offer carbs with their substantial industry presence and customer base for less expensive entry level boats.

To answer the sea trial question, I did not take a sea trial. I realize it is the ultimate silly thing to do but my emotions got the best of me and I had to have the boat. Only time will tell if my gut was right.

 

[mcleaves]

Re: What did the dealer mean..tap to start?

That's I why I looked so hard for an MPI
v6 but was nearly impossible to find a used one not at a dealer in a small boat.

Ummmmmm. You HAD a V6 MPI in your hands AND it was a Volvo.

And Fishermark is right.. If you have to tap it, it needs fixin'. Sticky float or needle valve. I wonder what causes that? It couldn't be sitting and lack of use could it?

M

 

[Barnacle_Bill]

Re: What did the dealer mean..tap to start?

The time will come when all the tapping in the world won't help. That is not normal.

 

[tarheelebbtide]

Re: What did the dealer mean..tap to start?

Methinks the person you are buying from wouldn't give you this particular advice unless he's had to do it a few more times than once. Carbeurated engines are just fine as long as you take the time to learn how to start them properly. Just put the thing in neutral, pump it full open twice and leave it set at 1/4 to 1/3 of WOT. She'll start and purr every time. With regard to your boat and the "tapping" issue though, if you find that you have to do it, you need to have the carb rebuilt. The carb is the only place on the top of the motor that tapping is going to accomplish anything, so it means a sticking needle valve or float.

 

[tysonnathan]

Re: What did the dealer mean..tap to start?

have you thought about rigging up a little machine that taps it for you??? an "autotapper", if you will. maybe you could use an old widshield wiper motor with adjustable intermittent settings. that way you could adjust the frequency of the taps... (i should make this contraption and get myself a patent!)

seriouslythough, a carb rebuild is probably in order and not that expensive.

(i could have used the autotapper on my starter a while ago, but i rebuilt it instead...)