There was a thread sometime ago with ways to test the motor but I can't find it now. Maybe it was on the old site?
Anyway I remember someone had posted as a way to check the spark or check for other cylinder issues you could pull a plug wire and the motor would run ruff replace and it runs better, or if you pulled the wire and nothing happens you got issues.
Well I tried this. I pulled the right side nothing changes put the wire back on nothing changes. Pulled the left plug wire and the motor dies?
Any ideas??????

Are you having any problems with the motor running? If not thats normal mine will due the same thing it's like 1 cylinder is actually doing all the work and the other is just there to help it out. Mine won't actually kill it will just run really bad when I pull that wire if yours is killing you might have a dead cylinder. Whats your rpm's out of water?

Do you have a leakdown tester? If not Harbor Freight has a decent cheap one.


Could be a number of things, but a leaky intake gasket or a valve seeping could be the problem. Also pull the valve cover on the dead cyl and see if everything is operating correctly.

How does it run in the water? If you are really only running on one cylinder, I have found that the most likely problem is the diodes. Its easy to fry them. You will be running like crap in the water if that is the case (like 8 mph).

I will bet you Sandmans last paycheck that your intake valve is not opening and closing properly.


Pull valve cover and check.

Taking it over to Sheldon at Gecker to look at it. I haven't had a chance to get to it. The LIGHTNING strikes have been keeping us busy all weekend.

Lot to be said for doin what you know
and takin it in to them that know...

For those who want "The rest of the story" as Paul Harvey would say.
Turns out valve lash adjustment was done but the real trouble was the emulsion tube in the carb had not been seated completely and was loose so it was running lean, and the plug wire boot has a tear in it so maybe it wasn't getting enought spark at idle. Replaced the boots with some fancy hot rod go cart boot and all is well.
Trip to the lake, deep water 4 guys (2 at 250+ 2 at 200) 23.9 on the GPS.
By myself 28 and 4500 rpm.

He's running a stock carb.

Gecker Motorsports are well known in the Lawn Mower racing and go carts circles. Many of the Lawn mowers have to remain "stock" or use only stock parts. Sheldon has made a business out of making these thing go faster. So it was only 1 step away from the mud motor from the lawn mower. He added a cam to my 36 and cleaned up the intake and carb. Head work, valves changed and case gasket. Stock exhaust modified until he gets his new pipe bender. All of this including labor $1300 and making close to 50HP. Moving a 3 man hide with 4 guys 24 to 25 mph priceless.

Just got the Steelflex in from Fasco Epoxies last night. So the boat goes up in the air for a paint job this weekend.

Thanks Stephen. We really appreciate your business and we are happy that the performance you wanted is what you got!

The stock carb can actually provide you with a lot of HP gains the way we prepare them. We machine the carbs in our Fadal VMC CNC machine and get the perfect shape. It is actually a really slick deal! The stock carb actually ends up with a total size larger than that of the Mikuni carb so performance is good! We have been doing these mods for a ton of years and can do any type of engine.

Some of the stock Briggs 2 barrel carbs have press fit issues on the emulsion tubes. If the engine runs lean on one bank, this could be a source of the problem. If the emulsion tube is allowed to bleed vacuum off, it will not pull fuel and cause that cylinder to be lean.

On the plug boot-the cut in the boot was contacting the shroud. The result there is a grounded spark.

Thanks
Sheldon

http://www.mudboatmotor.com