MECOA's Model Engine Forum & Swap Shop

cdxanti · Joined: 22 Jul 2010 Posts: 4

I was given a 3.5 awhile back and I have never been able to get it to run.
The engine puts out no backpressure. So no fuel is being delivered. I believe it has the wrong exhaust adapter on it. Their is a gap between the head and the adapter that looks like is supposed to be their. I'm open to any suggestions.

SteveM · Posted: Fri Jul 23, 2010 4:22 am Post subject:

Is this an inboard or outboard motor?

cdxanti · Joined: 22 Jul 2010 Posts: 4

outboard

SteveM · Posted: Fri Jul 23, 2010 2:31 pm Post subject:

Is the header perhaps an after market type designed for an exhaust throttle? Can ypu post a picture?

cdxanti · Joined: 22 Jul 2010 Posts: 4

SteveM · Posted: Sat Jul 24, 2010 12:32 pm Post subject:

Looks to me like you have the header designed for the exhaust throttle for sure. You'll need to replace that with a new stock one. The red carb is from the older 7.5cc inboard motor and is a PITA to tune on a stock 2.5 outboard. I'd recommend the black or gold carbs instead.

cdxanti · Joined: 22 Jul 2010 Posts: 4

so getting the right adapter would help with my back pressure problem?
Also I have another lower end that doesn't have a pressure fitting at all and is shorter than the one shown in my photo. is this for the exhaust throttle control?

SteveM · Posted: Sun Jul 25, 2010 4:15 am Post subject:

mrmodify · Joined: 25 Jul 2010 Posts: 1 Location: B.R. Louisianna

Have a 3.5 outboard had trouble with it for years. It never would run a 6oz tank dry. Some of the time it wiould make 2 -3 laps on pond then die. Most of the time it would go about 40' and die. Changed all kind of parts with no luck. Talked to Conley engines and was gonna put a Perry fuel pump on it. Conley talked me into putting a Perry carb on it. The boat now will run the 6oz tank dry at any speed you want as many times as you want..