tohatsu 30 runs on one cylinder

[mcskis]

Hi my 30 hp barely runs after not using for three months. Usually clogged injector form corn gas, so i unplugged each injector while engine was running(one at a time) engine didn't die till i pulled the middle injector wire loose. took out all three injectors, cleaned, pushed sea-foam through till pretty stream from each of the little holes(using 5/8 hose and 15 psi etc.) tested switching using a low voltage and was able to turn on and off spray. re-installed no difference. Do i need to look at electronic brain box? The plugs all looked good. Anything else i can try before i pull out of water and take to a dealer? Mark

 

[pvanv]

Re: tohatsu 30 runs on one cylinder

I'm assuming you have an MFS30B (you didn't mention model). What do the plugs look like? What is the fuel pressure? What is the compression? When was the last time you drained the vapor separator? (you should run the fuel out and drain the separator any time the motor is to be stored 30 days or more). Did you run the electrical checks on the ignition system?

In short, the 30B is not a "shade tree mechanic" serviceable motor; if you want to become versed in servicing it, start by getting a Factory service manual (from any delaer, including me), and troubleshoot the motor, using the manual as a guide. Or, if you prefer, take it in to a dealer.

 

[mcskis]

Re: tohatsu 30 runs on one cylinder

mfs30b (fuel injected with controls) plugs to me looked good, light grey, clean, dry all similar. pressure 44 psi. see previous post for last injector performance and method(appeared excellent once cleaned). I could't find my compression gauge, probably under that tree. Drained v separator, looked clean, fuel filter clean.

Mostly curious about the middle cylinder running so good and that test i did (read my post)thought that might narrow it down.

So, I was trying to eliminate the fuel system without buying a manual and stopping work. I'll need a manual to do the electrical side,, unless i had a little help. Anyway as of this writing, It's now at the $dealer$hip.



What do the plugs look like? What is the fuel pressure? What is the compression? When was the last time you drained the vapor separator? (you should run the fuel out and drain the separator any time the motor is to be stored 30 days or more). Did you run the electrical checks on the ignition system?

In short, the 30B is not a "shade tree mechanic" serviceable motor; if you want to become versed in servicing it, start by getting a Factory service manual (from any delaer, including me), and troubleshoot the motor, using the manual as a guide. Or, if you prefer, take it in to a dealer.[/QUOTE]

 

[TOHATSU GURU]

Re: tohatsu 30 runs on one cylinder

This model engine requires computer software to diagnose the system. No software = WAG. Check and make sure your dealer has the software or you are just throwing your money down a rat hole.

 

[mcskis]

Re: tohatsu 30 runs on one cylinder

My wild *** guess (since it only stalled when i pulled the center injector connector) was coils or ecm. RESULTS: upper and lower coil. Seems like a simple voltmeter or spark checker could have confirmed this. Yes they have map software etc. They are ordering parts(coils) at this time.

 

[pvanv]

Re: tohatsu 30 runs on one cylinder

The ignition checks are done with a good analog volt/ohm meter, using the Factory service manual as a guide. What were the resistance values?