7.5 Tecumseh Game Fisher only starts/runs full throttle

[X80057X]

Re: 7.5 Tecumseh Game Fisher only starts/runs full throttle

I'm feeling really distraught damn near admitting defeat :-(
The restrictor idea was a total fail. I've now got the carb apart and soaking in vinegar over night. It's almost a last resort. Maybe there's some tarnish buildup that's just enough to lean it out? When I pull the plug now it's dry and white, no good. The main jet bolt that holds the bowl in place is the one with just a single hole in the stem. I'm thinking to open it just a bit if the vinegar doesn't work.

 

[Tim Frank]

Re: 7.5 Tecumseh Game Fisher only starts/runs full throttle

After watching some YouTube videos I learn that the seat needle is suppose to be affixed to the float. Not having a blueprint to follow when reassembling due to the original being MIA, and no prior 2 stroke carb experience, I did not know this. Hopefully this solves the issue.....stay tuned.*

That carb is no different from 1000 other carbs used on TEC 4-strokes that power snowblowers, lawn mowers etc..
This thread would probably have better luck in the non-boating technical section.

Manuals are available and would help you a lot.
gamefisher outboard motor parts

As far as 4stroke vs. 2-stroke, you still need the basics for it to run...spark, fuel, compression.
Have you checked compression on this motor?

The missing float needle completely explains the flooding .... but you haven't said yet whether you removed the welch plugs when you cleaned the carb. Until you do that, the carb isn't clean.

You have described a home-brew redesign of the fuel feed. The gravity feed tank avoids the need for a fuel pump...how do you get around that absence with a remote tank?

 

[X80057X]

Re: 7.5 Tecumseh Game Fisher only starts/runs full throttle

I guess I failed to mention that amongst so many things tried yesterday I did remove the welsh plug. Blasted it with carb cleaner and poked it with a strand of copper wire. I removed my "homebrew" restrictor as it didn't work at all. For now I have the motor mounted in a 55 gal. drum of water and elevate the remote tank on the bed rail of my truck, which does sit higher than the motor. I have checked compression which is good. It has spark.

My bowl of vinegar has all sorts of crap floating around in it. I guess I'll cross my fingers and hope that just one of these countless particles was clogging a fuel passage. Thank you for the link to the manual. I hadn't seen a tech section or I'd have probably posted there. Maybe a mod could move this thread????

 

[Tim Frank]

Re: 7.5 Tecumseh Game Fisher only starts/runs full throttle

The non-boating technical question section would have lots of eyes on it from folks who are running TECs in various applications.
Most of the TECs use Tillotson carbs, and they are all nearly the same layout.

That remote tank probably has a feed tube that draws from the bottom....not what is required.
The integral tank on that motor was/is a gravity feed that flows out from the bottom.
You are relying entirely on a siphoning action.
I don't think it will work.

http://www.justanswer.com/boat/3uskl-just-given-7-5-hp-sears-gamefisher-boat-motor.html

 

[X80057X]

Re: 7.5 Tecumseh Game Fisher only starts/runs full throttle

But this particular layout of the motor has a nipple and petcock specifically designed for a remote tank. Even factory stickers on the motor casing that says, and I'm looking at the sticker right now while I quote, "close fuel shut-off valve when using a remote tank." This particular model was designed for optional use of a remote tank. And even still, at current, the remote tank sits higher than the carb which would create a gravity feed.

 

[X80057X]

Re: 7.5 Tecumseh Game Fisher only starts/runs full throttle

Funny, I've read that link last week. That's one of the links I mention here in an earlier post that has no resolution to the problem. Most of my googling leads to a dead end. Many similar issues but nobody posts a fix. That's why I finally joined this forum in hopes for some further guidance.

 

[X80057X]

Re: 7.5 Tecumseh Game Fisher only starts/runs full throttle

Ok.....It's running awesome thru the powerband but WILL NOT idle or start in neutral. I'm going to remove some **** and see if I can't make a throttle arm adjustment. Once I put it in gear and am able to open the throttle just past the neutral stopping point she starts and runs great!

 

[JB]

Re: 7.5 Tecumseh Game Fisher only starts/runs full throttle

Sounds to me like you have exhausted almost all possibilities that your carb is the problem. Let's consider some other (though remote) possibilities.

You could be having pumping troubles. When the carb butterfly is closed, as at idle, the crankcase vacuum on the upstroke is stronger than when the carb is open and admitting more air/fuel mix. If you have air leaks into the crankcase the mix from the carb gets diluted and may be too lean to fire. Crankshaft seals, gaskets on reed plates, carbs, cylinder to crankcase, bypass covers and seals between halves of crankcases all can leak air.

Another remote possibility is ignition timing. If timing at start is too retarded it may require advance of the throttle (and ignition timing) to get adequate advance to fire.

I suggest that you investigate possible air leaks and confirm synchronization between throttle and stator.

If all else fails, try borrowing a carb from a good performing engine or even replacing the carb with a chainsaw diaphram carb that has the built in fuel pump. Be sure that any replacement carb has the same or larger diameter venturi.

Good luck.

 

[Tim Frank]

Re: 7.5 Tecumseh Game Fisher only starts/runs full throttle

But this particular layout of the motor has a nipple and petcock specifically designed for a remote tank. Even factory stickers on the motor casing that says, and I'm looking at the sticker right now while I quote, "close fuel shut-off valve when using a remote tank." This particular model was designed for optional use of a remote tank. And even still, at current, the remote tank sits higher than the carb which would create a gravity feed.

But were they pressure tanks?

Are you getting no effect from adjusting the needle valve ?

 

[X80057X]

Re: 7.5 Tecumseh Game Fisher only starts/runs full throttle

From what I understand this motor doesn't have adjustable timing, being a single sator setup. Whatever that means. Although I think you're correct.....I decided with it now running mint through the powerband it just needed more fuel at idle and neutral. I set out to tweak, bend, and or redneck something to accomplish this. I pulled the flywheel to see what I could find, here's my results:

7.5 Tecumseh gamefisher idle adjustment - YouTube

I feel she could still use some adjusting and tweaking but I layed down my trusty drill starter and gave her a tug:

7.5 gamefisher Tecumseh "Eska" - YouTube

 

[X80057X]

Re: 7.5 Tecumseh Game Fisher only starts/runs full throttle

Thank you to everyone who helped and commented. Although I'm far from a forum noob, I obviously am new to this forum. Your hospitality is greatly appreciated!!!! I'm happy to have found a solution having it now documented in the Internet air for others to utilize. I become so frustrated with dead end posts. Again, thank y'all!!!

Be smarter than the machine! Persistence pays off! time to go fishing!

 

[X80057X]

Re: 7.5 Tecumseh Game Fisher only starts/runs full throttle

Tim frank; the stock tank has a vented cap just as my remote tank. Iirc, the idle needle screw is suppose to be at like 3/4 turn. I have it at about 3.5 turn for it to idle and be able to pop into gear. That's why I say I think it could use more tweaking and adjustment. But I'm happy. If you'd like to offer further suggestions I'd be happy to listen

 

[Tim Frank]

Re: 7.5 Tecumseh Game Fisher only starts/runs full throttle

This might be of some assistance.


http://www.allotment.org.uk/assets/rotovator/Tecumseh-2-cycle-engines-manual.pdf

 

[X80057X]

Re: 7.5 Tecumseh Game Fisher only starts/runs full throttle

Whoa, sweet! Thanks bud!!! I Hadn't even tried to search a manual ��

 

[MahtyMaht]

Re: 7.5 Tecumseh Game Fisher only starts/runs full throttle

Not getting fuel? You do have the orange fuel pump element slot ends at 8 and 2 oclock, don'tcha?

 

[MahtyMaht]

Re: 7.5 Tecumseh Game Fisher only starts/runs full throttle

The timing advances when you open the throttle. Tweaking the position of the cam under the flywheel just changes the throttle position relative to timing.

 

[X80057X]

Re: 7.5 Tecumseh Game Fisher only starts/runs full throttle

The pump element is at around 8 and 2, yes. And are you commenting on my idle adjust video link I posted? Cause yeah, I popped the flywheel to see an adjustment lever. I adjusted it.

 

[X80057X]

Re: 7.5 Tecumseh Game Fisher only starts/runs full throttle

The guy I bought everything from last year had said he at one point had a buddy go through the entire motor. So I really don't know what's still spec from factory and what isn't. Obviously the buddy wasnt the brightest bulb having installed the wrong spark plug. It ran great through the powerband after the vinegar but still wouldn't idle or start in neutral, to which I decided it needed more fuel at low throttle. However, instead of about 3/4 turn on the idle adjust needle screw...I have it at about 3.5 turns. So something still needs tweaking for sure but she idles and starts in neutral, with the pull cord!

 

[MahtyMaht]

Re: 7.5 Tecumseh Game Fisher only starts/runs full throttle

The two fuel line nipples are a dead giveaway that you have a fuel pimp element in there. Mine has no problem lifting fuel 30" thru a 1/4" fuel line. You need the remote tank fitting capped if you're using the engine tank. I forgot to mention checkin' those chrystler quick disconnect fuel fittings - they have check valves and o-rings, and they can mamke you chase your tail, too, when there's trash knockin' around in'em.

 

[X80057X]

Re: 7.5 Tecumseh Game Fisher only starts/runs full throttle

I'm using the remote tank as the stock top mount tank is destroyed, rusted on the inside with even a rot hole in one corner. Maybe come winter I'll take it off, cut it in half, and attempt to clean it up....maybe, lol!!! As far as the quick connect I don't have one on the fuel line. I slip on the hose and use a pinch style clamp to secure it. It fits very snug.

Today I launched her maiden voyage with my buddy. Unfortunately I tagged some waterlogged driftwood which left us putting back to shore on the trolling motor. I haven't tore into her but I'm crossing my fingers it's simply the shear pin. Scope it, I was hootin like an idiot, Hahahaha!!!! :-D

7.5 gamefisher in action - YouTube