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Fuel in Exhaust?

02 May 2020 15:34
Cruiser84
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Fuel in Exhaust? #1
Finally got my DT1B back together and running fairly well, but kept bogging down on little hills... to the point of having to drop into second just to putt to the top.

I decided to give it a break for the day and came back to it today. After several attempts to kick it over, I had no luck. I tried adjusting the a/f screws, but that made no difference. SOOO, once again I pulled the carb and checked the bowl, blew out all holes and put it back together. Spark, compression, battery and fuel are all good.

I then noticed that gas or condensation was leaking out the exhaust manifold. I removed the exhaust pipe and tried kicking it a few times to see if that would relieve any pressure, but I until I almost caught the damn bike on fire. So here I am, close, but no kiss kiss no bang bang.

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02 May 2020 17:30
Swoop56
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Fuel in Exhaust? #2
If you have raw fuel in your exhaust , it can only be coming from the carb .
Perhaps float level is too high , Needle and seat valve not sealing completely .
The fuel tap may not shut off completely in off position either , but it would require
the float valve to be faulty too .
I turn off the fuel a couple of hundred metres before stopping , so I don't have a full
bowl of fuel onboard whilst sitting . It used to make starting again much more consistant .
That's on the same bike as yours .
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02 May 2020 20:31
FrankC
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Fuel in Exhaust? #3
When I removed the silencer on my 400 I had no power at all. Seem like some back pressure is needed. Check fuel as above stated, check compression if it won't climb hills, perhaps pipe also clogged or losing too much back pressure. Just a thought anyway. Too much or too little back pressure bad.
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03 May 2020 14:41 03 May 2020 14:46 by Cruiser84.
Cruiser84
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Fuel in Exhaust? #4
Back at it today. Pulled air filter and carb. Floats move freely and I am not getting any overflow from tube. Blew out all ports for about the 30th time. Changed to a new needle to see if that would help, but still no luck on getting it to kick over. Still have gas leaking from exhaust.

I’m at a loss on what to do. On the up side, I am lightning fast at removing, taking apart and reinstalling the carburetor. Who needs a pit crew member?!

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03 May 2020 15:49
Mothersbaugh
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Fuel in Exhaust? #5
Unfortunately for your pit crew future, I think we are all pretty good at removing and re-installing a carb. :Buds
Fast, too.
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03 May 2020 16:23
Schu
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Fuel in Exhaust? #6

Mothersbaugh wrote: Unfortunately for your pit crew future, I think we are all pretty good at removing and re-installing a carb. :Buds
Fast, too.


Carb-Swapping Competion (a new sporting event)

Ok, everybody.....

On your mark! (grab your shop stool)
Get set! (Pickup your tools)
BANG!

Schu

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03 May 2020 16:48
Swoop56
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Fuel in Exhaust? #7
There is possibly still a belly load of fuel still in the crankcase . Pull the spark plug out
and kick it through 20 times , ( with ignition turned off obviously ) .
A fresh plug might help too .
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04 May 2020 00:24
Gr8uncleal
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Fuel in Exhaust? #8

Swoop56 wrote: There is possibly still a belly load of fuel still in the crankcase . Pull the spark plug out
and kick it through 20 times , ( with ignition turned off obviously ) .
A fresh plug might help too .


Or as Swoop says, but snick bike into second or third and push around for a few minutes.
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04 May 2020 11:54
apex
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Fuel in Exhaust? #9
Or your spark arrestor is plugged/restricted. Take the tip and arrestor out and see how it runs. If it's better, then you'll need to start cooking the pipe!

Allrighty Then
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04 May 2020 16:44
darinm
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Fuel in Exhaust? #10
It's amazing how much fuel can get in there. I'm with the guys on pulling the plug and pipe, putting it in 3rd and finding a nice long hill to go down, petcock and ignition off of course. Then install a fresh plug and the pipe and see what happens.

1972 Yamaha CT2 175
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