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Old Sep 01, 2014, 04:01 PM
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dan n's Avatar
chicagoland
Joined Oct 2006
36 Posts
Question
Zenoah G-26 on Shockwave 55

I just bought a used Shockwave 55 with a Zenoah G-26. I can't get it to start. It has spark. wasn't sure if it was getting fuel so I took the carb apart and throughly cleaned it (not a rebuild with new parts) everything looked good. when I put it back together and tried to prime with the bulb, no gas comes into the bulb and air bubbles go back in the tank every time I push the bulb. I changed the gas lines and put a new tank in it too. When I cleaned the carb, I pulled out the little red rubber valve that you see through the bulb and put it back in. could I have ruined that piece by doing that? there are 2 lines going to the tank, does it matter which side they go on? help!
thanks,
Dan (1st time boat owner and gas engine)
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Last edited by dan n; Sep 01, 2014 at 05:58 PM.
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Old Sep 01, 2014, 04:38 PM
Registered User
cocoa, Fla
Joined Jul 2009
260 Posts
yes it does matter, change your lines from one barb on the carb to the other and see if that works.sounds like they are just on backwards.
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Old Sep 01, 2014, 05:56 PM
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dan n's Avatar
chicagoland
Joined Oct 2006
36 Posts
tried that, doesn't make any difference. still just blows air bubbles back into the tank. maybe the little primer valve is bad? doesn't look bad. I'm stumped.
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Old Sep 01, 2014, 09:57 PM
RC boat Rock Star
Kalamazoo, MI
Joined Apr 2004
2,940 Posts
Try this. If it isn't getting any fuel at all after pulling off the carb, check the gasket between it and the isolator block as it may be on upside down. There is a small hole for the pulse port and if it's blocked you won't get any fuel to the carb. Some gaskets have two holes so that you can't mess it up while others only have the one hole in them.
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Old Sep 04, 2014, 11:43 AM
Registered User
Joined Apr 2008
504 Posts
You cold have a cracked fuel lines inside the tank? Or try soaking the primer valve then put the primer bulb back on with fuel inside. Try replacing all the lines and fuel filter. I doubt the gasket behind the isolator is upside down if you can't get fuel in the primer bulb then no fuel is in the carb. If the fuel bulb fills and the engine starts but won't stay running then isolator gasket may be upside down. Also Too much oil can cause a engines to not start. Use quality synthetic oil and 93 or higher octane. Yes octane dose make a difference in performance.
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Old Sep 22, 2014, 09:27 AM
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Jersey
Joined Mar 2010
118 Posts
Hi Ron its buddman36, I was running a my new 4 bolt CY 27 modified engine yesterday and it wont hold an idle for more than 30-45 seconds ? It is a brand new motor but I would think it should at least hold an idle for longer than that, also the primer bulb while running is very bubbly/foamy but I was told that is normal due to vibration of the modified motor? Any idea what may be wrong ? I checked all gaskets and don't seem to have any leaks around them, do you think it just needs more breakin time, also its a 771 walbro carb to which I think I will replace with a none bulb 257 or 1048 big bore carb ? Whats your thoughts ? By the way the engine runs great while under throttle but idling is a prob, I do have a clutch installed.
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Old Sep 22, 2014, 09:47 AM
RC boat Rock Star
Kalamazoo, MI
Joined Apr 2004
2,940 Posts
Usually there's nothing wrong with the 771 carb although it's not as popular as the 257. Some people prefer it over the 257 but I haven't seen any big difference in the performance of them.
Idle speed too low? Take it up some and see if that helps.
I've had engines broken in with maybe 1,000ml of fuel through them. I use Baxter IV bags so that's how I know the metric system. I run the snot out of them during break-in.
The Sikk/CY's have a very weak spark so take the plug gap down to around .016".
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Old Sep 25, 2014, 08:23 AM
RC boat Rock Star
Kalamazoo, MI
Joined Apr 2004
2,940 Posts
If you're getting air into the tank when you try to prime it then the lines are backwards. I have to agree with Tom on this. Usually the line from the primer to the tank isn't needed as all it does is return any extra fuel from it back to the tank which most of the time is very little to none.
You don't have to use the primer either. Just stick your thumb over the barrel and pull the engine over slowly to draw fuel into the carb. When your thumb is wet then it's primed.
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