97 with strange blow back problem

richardd · 10-06-2009, 05:57 PM

I have a 97 OHV engine Serial # of the cart is AF9741-614250 and the engine number is FA290D-S10. I acquired this cart with others in a lot of 6 carts. The strange problem I have is that I am registering 180 psi compression but when the cart is running, I get an awful lot of blowback through the air intake system. When I place my hand over the intake it blows my hand away about as much as it sucks it in when running. Any ideas as to why this would be happening.

crash12888 · 10-06-2009, 09:56 PM

Pull the valve cover and adjust the valve cearance to .004 both intake and exhaust. Do it cold.

richardd · 10-07-2009, 03:44 AM

Thanks for the reply Crash. I will check the valves today. There is a new development. I pulled the carb and found there was no butterfly valve in the carb. I noticed the cart wanted to run full throttle when it ran. So I know that there needs to be a butterfly there. Could the blow by be related to not having a butterfly?

Would the valve clearance allow me to have good compression when cranking, but excessive blow by when running?

I have more experience with Yamaha G1's than Club Cars so any help is appreciated.

I acquired this cart along with 5 others in a group I purchased. So the history is unknown on them.

crash12888 · 10-08-2009, 07:45 PM

The throttle plate would restrict alot of the blow back. Is the screw still in the shaft?

richardd · 10-15-2009, 06:07 AM

The screws were still in the shaft. I found another butterfly from another carb and the shaft hole pattern matched, but I had to reduce the outside diameter a fraction to get it to work. I spoke to a cart mech and mentioned the butterfly being gone. Someone must have taken it out, but he said that sometimes they just disintegrate. Not sure I am understanding that. I now have throttle control and the blow back seems to have gone away a lot. I also adjusted the valves. They were set with a lot of clearance before I readjusted to .04. The cart seems to be running pretty good now. Thanks to all for the suggestions.

crash12888 · 10-15-2009, 07:40 AM

I've never seen one just disinagrate but that's not sayin Spock couldn't walk by and hit it with his Phaser!
Glad you got it worked out.

scottyb · 10-15-2009, 09:05 AM

I have seen a few that swallowed the throttle plate .... well the screws atleast

DOOmsman · 10-15-2009, 10:38 AM

The previous owner may have used the cart as a donor.

richardd · 10-25-2009, 05:16 AM

The cart was used by the company I work for as personal transportation around the facility. As it turns out, just before the cart quit running well, a couple of guys were seen "messing around" with it. At the time nobody thought anything of it. I suspect that one of them "needed" a good carb and stuck the one they screwed up on it. So the company got another cart and shoved this one off to the side when it wouldn't run well. After sitting several months, I acquired it.

10-06-2009, 05:57 PM	#1
richardd Not Yet Wild Join Date: Sep 2009 Posts: 23	97 with strange blow back problem I have a 97 OHV engine Serial # of the cart is AF9741-614250 and the engine number is FA290D-S10. I acquired this cart with others in a lot of 6 carts. The strange problem I have is that I am registering 180 psi compression but when the cart is running, I get an awful lot of blowback through the air intake system. When I place my hand over the intake it blows my hand away about as much as it sucks it in when running. Any ideas as to why this would be happening.
richardd Not Yet Wild Join Date: Sep 2009 Posts: 23

10-06-2009, 09:56 PM	#2
crash12888 Gone Crazy Join Date: Jan 2007 Location: Chesterfield, Va Posts: 6,021	Re: 97 with strange blow back problem Pull the valve cover and adjust the valve cearance to .004 both intake and exhaust. Do it cold.

10-07-2009, 03:44 AM	#3
richardd Not Yet Wild Join Date: Sep 2009 Posts: 23	Re: 97 with strange blow back problem Thanks for the reply Crash. I will check the valves today. There is a new development. I pulled the carb and found there was no butterfly valve in the carb. I noticed the cart wanted to run full throttle when it ran. So I know that there needs to be a butterfly there. Could the blow by be related to not having a butterfly? Would the valve clearance allow me to have good compression when cranking, but excessive blow by when running? I have more experience with Yamaha G1's than Club Cars so any help is appreciated. I acquired this cart along with 5 others in a group I purchased. So the history is unknown on them.
richardd Not Yet Wild Join Date: Sep 2009 Posts: 23

10-08-2009, 07:45 PM	#4
crash12888 Gone Crazy Join Date: Jan 2007 Location: Chesterfield, Va Posts: 6,021	Re: 97 with strange blow back problem The throttle plate would restrict alot of the blow back. Is the screw still in the shaft?

10-15-2009, 06:07 AM	#5
richardd Not Yet Wild Join Date: Sep 2009 Posts: 23	Re: 97 with strange blow back problem The screws were still in the shaft. I found another butterfly from another carb and the shaft hole pattern matched, but I had to reduce the outside diameter a fraction to get it to work. I spoke to a cart mech and mentioned the butterfly being gone. Someone must have taken it out, but he said that sometimes they just disintegrate. Not sure I am understanding that. I now have throttle control and the blow back seems to have gone away a lot. I also adjusted the valves. They were set with a lot of clearance before I readjusted to .04. The cart seems to be running pretty good now. Thanks to all for the suggestions.
richardd Not Yet Wild Join Date: Sep 2009 Posts: 23

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10-15-2009, 07:40 AM	#6
crash12888 Gone Crazy Join Date: Jan 2007 Location: Chesterfield, Va Posts: 6,021	Re: 97 with strange blow back problem I've never seen one just disinagrate but that's not sayin Spock couldn't walk by and hit it with his Phaser! Glad you got it worked out.

10-15-2009, 09:05 AM	#7
scottyb Happy Carting Join Date: Dec 2007 Location: Southern California Posts: 73,406	Re: 97 with strange blow back problem I have seen a few that swallowed the throttle plate .... well the screws atleast

10-15-2009, 10:38 AM	#8
DOOmsman Gone Wild Join Date: Jul 2008 Location: Reddick IL Posts: 11,220	Re: 97 with strange blow back problem The previous owner may have used the cart as a donor.

10-25-2009, 05:16 AM	#9
richardd Not Yet Wild Join Date: Sep 2009 Posts: 23	Re: 97 with strange blow back problem The cart was used by the company I work for as personal transportation around the facility. As it turns out, just before the cart quit running well, a couple of guys were seen "messing around" with it. At the time nobody thought anything of it. I suspect that one of them "needed" a good carb and stuck the one they screwed up on it. So the company got another cart and shoved this one off to the side when it wouldn't run well. After sitting several months, I acquired it.
richardd Not Yet Wild Join Date: Sep 2009 Posts: 23

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