2007 Johnson 15HP carburetor(?) problems

[beaufort bob]

Re: 2007 Johnson 15HP carburetor(!) problems

Re: 2007 Johnson 15HP carburetor(!) problems

Yesterday (1/5/2007) I had an appointment with the dealer. We talked more about the mid-range rpm disfunctionality of the motors (one more than the other). Then I watched for 2 1/2 hours while he patiently and carefully disassembled the carburator on the more badly behaving engine. He took his time, cleaning and tracing the fuel and air pathways through the carb, not having seen this particular model before. A small obstruction of some sort appeared to have been cleaned out by use of the Honda liquid cleaner (a frightening carcenogenic combination of toluene, methanol and methylene chloride) and air hose. The carb was then re-assembled and put back on the engine.

Starting was easier but the mid-range problem was not completely solved until he changed the idle richness valve setting, increasing the richness by several turns. While this had no effect on the idle speed or behaviour, all of the mid-range engine coughing and choking completely disappeared. He then did the same adjustment on the other engine with the same effect.

I field tested the two engines when we were done and they now work well throughout the full range of rpms.

So what do we learn from this? Perhaps each person has their own way of doing a job, and sometimes it's necessary to be more patient than usual to find out how to approach the person whose services you need. Although a little difficult to pin down because of scheduling problems, once the dealer began to work on the problem, he did excellent work.

I'm looking forward to attending his motor maintenance and repair classes this year.

HK,

Thanks for taking the time to direct me to this thread.

Sounds to me like you have "lucked out" with a dealer who cares. Can't say the same for myself WRT dealers, and Suzuki won't answer my written inquiries (after their original "form letter" response. )

Glad you had success, and thanks again!

BB

 

[seahorse5]

Re: 2007 Johnson 15HP carburetor(?) problems

Congatulations on your relationship with your dealer "stidown" and for having good running motors now.

Is your dealer going to order you the service manual now?

 

[Hilo_Kawika]

Re: 2007 Johnson 15HP carburetor(?) problems

Well, it's about a year later and time for an update. Sadly, my original dealer has gone out of business but the good news is that there is another dealer who has set up shop in the meantime. I was able to order the ~$80 manual through him.

After inital success, the engines went back to their old poor mid-range performance. Sigh...

In Hawaii, we are mandated to use a 10% ethanol / 90% gasoline mixture in our cars. On the East side of Hawaii Island there is now only one service station that sells "pure" gasoline and that only from a single pump at $4/gal.

As it turns out, the midrange poor performance issues were caused by using the 10%/90% mixture. When the factory tunes up the engines, they use 100% gasoline not 10%/90%. Although the engines are warranteed for fuels with a certain octane level (achieved by the 10%/90% mixture), the factory rep admitted that the mid-range problems were probably a result of the mixture. When we removed all the 10%/90% mixture from the carburetor and lines, substituted 100% gasoline and re-adjusted the fuel richness screw, the engines ran well at all rpms.

So my solution is once a month to make a 30 mile round-trip and buy 15-20 gallons of 100% gasoline for use with my boat engines.

Of course at this point, the starter has crapped out on one of the engines and both RPM indicators are haywire so it's back to the repair shop with a three week wait for parts. I should have bought Honda's...

 

[UndertheRadar]

Re: 2007 Johnson 15HP carburetor(?) problems

I am having the same problem with my '03 15 hp Johnson 4 stroke. I will do as this thread says and hope for the best. IF you are still around Iboats, how about posting an update? Was this a permanent fix???