Stalling

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mkozan
Still in the Driveway
Posts: 2
Joined: Mon Jul 02, 2018 12:00 pm
Country: Canada
Suzuki 2-Strokes: GT750

Stalling

Post by mkozan »

I recently repaired the water pump and rebuilt the carbs(amongst a few other repairs) on my 72 GT750 it seems to be running well when i start it up and it drives great unit it gets up to temp then it seems to bog out then stall out. Once i let it sit for a few it fires back up and runs fine. Any advice would be great i'm kind of at a loss.
thanks!
Mike
Boise
On the street
Posts: 14
Joined: Wed Jun 27, 2018 4:27 pm
Country: United States
Suzuki 2-Strokes: GT380 1974

Re: Stalling

Post by Boise »

mkozan wrote:I recently repaired the water pump and rebuilt the carbs(amongst a few other repairs) on my 72 GT750 it seems to be running well when i start it up and it drives great unit it gets up to temp then it seems to bog out then stall out. Once i let it sit for a few it fires back up and runs fine. Any advice would be great i'm kind of at a loss.
thanks!
Mike
Very difficult to diagnose from here, but by what you describe it sounds like fuel supply before ignition issue, but both need to be checked to be honest in diag.

Have you checked fuel flow? Sounds like it is starving out once under load, then being replenished as it sits by the side of the road. Unless you have a non-vacuum petcock, a starved bowl will (normally) never fill while not running unless petcock is switched to Prime. But what you describe might happen even in PRIME setting if the filter screen in the petcock is plugged with gook.

Hope that helps you focus on a few things. Go about it systematically from tank inlet to float bowls and you'll find the issue. (Unless it is ignition, then...)
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tz375
Moto GP
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Joined: Mon Nov 03, 2008 10:47 am
Location: Illinois

Re: Stalling

Post by tz375 »

I'd start with the filler cap. See if it breathes as it is designed to. Air has to enter to replace the fuel that's coming out or else it will stop flowing. If the filler cap is OK daring the tank and clean out the fuel tap. If it's clogged, flow will be restricted.
sportston
Expert racer
Posts: 1119
Joined: Wed Jul 10, 2013 12:04 pm
Country: England, UK
Suzuki 2-Strokes: FZ50, GP100, RG125 Gamma, GT380, Bandit 1200S

Re: Stalling

Post by sportston »

+1
They're both right. lol
I agree that it sounds like a fuel starvation problem.
TZ's idea of fuel filler cap breather being blocked is a great place to start looking.
Then check fuel filters and fuel tap like Boise suggested.
sportston
Expert racer
Posts: 1119
Joined: Wed Jul 10, 2013 12:04 pm
Country: England, UK
Suzuki 2-Strokes: FZ50, GP100, RG125 Gamma, GT380, Bandit 1200S

Re: Stalling

Post by sportston »

There is just a couple of other things.
Do you have enough coolant? Is there any chance you have air locks causing the engine to get too hot and getting tight?
Another possible cause of fuel starvation that gives similar symptoms is carb icing. What air temperature are you riding in?
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