Suzuki Samurai Propane tuning

Propane, Butane, LPG, GPL, C3H8, C4H10
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6cummins1
Posts: 5
Joined: Thu May 04, 2017 9:08 am

Suzuki Samurai Propane tuning

Post by 6cummins1 » Thu May 04, 2017 12:19 pm

Whats up guys. Been digging the past couple days on the web for info on tuning a propane setup without much luck. I finally ran across this forum and seems like there is some solid knowledge here. I did some searching on here before I decided to ask but really couldn't find much so I figured Id go ahead and ask. I've got a Suzuki Samurai 1.3 with a long tube header that is strictly an off-road toy. I ordered a propane kit from http://www.gotpropane.com since he sells a complete kit ready to go. It is a Impco 100 mixer and a Model J regulator. Got everything installed and it runs well without adjusting anything. To my understanding he said he sets the mixers "power screw" if I recall that is what its called before sending them out but not the idle mixture. Well I added a snorkel the other day because the type of riding I do I needed it for water and it seems a little down/flat on power now. I haven't tried running it yet without the filter on the snorkel to see if the filter may be restrictive, but I need a filter regardless so Ill purchase one that flows better if thats the issue. Anyhow I was curious if anyone could point me in the right direction on adjusting the idle mixture screw? I was told by the guy where I purchased it to get the motor up to temperature and back the screw out (leaner) until it didn't crank up as fast or as easy as it normally does and then screw it back in a hair and call it good. Is that a proper way to do it? Seems as if my motor makes a little more valve train noise when I do it that way at idle. Timing is set at factory 10* BTDC. Is there a certain RPM range that idle screw effects or is it strictly just idle rpm? Any help would be greatly appreciated.

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storm
Posts: 566
Joined: Wed Jan 10, 2007 10:10 pm
Location: NSW, Australia

Re: Suzuki Samurai Propane tuning

Post by storm » Thu May 04, 2017 3:50 pm

Idle mixture mostly affects idle and just off idle sometimes cruise as well. It has minimal effect on WOT.

Idle mixture setting is quite simple but you do need a few tools to do it like a tacho and a vacuum gauge. Here's a link for you that may help you in the future as well http://www.rasoenterprises.com/propane/ ... l-mixtures Going down to the heading Idle fuel mixture it says and this is how I do it "Once the engine is fully warm, set the idle mixture to provide the highest and steadiest idle speed at the vehicle's recommended idle speed."
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6cummins1
Posts: 5
Joined: Thu May 04, 2017 9:08 am

Re: Suzuki Samurai Propane tuning

Post by 6cummins1 » Thu May 04, 2017 4:23 pm

storm wrote:Idle mixture mostly affects idle and just off idle sometimes cruise as well. It has minimal effect on WOT.

Idle mixture setting is quite simple but you do need a few tools to do it like a tacho and a vacuum gauge. Here's a link for you that may help you in the future as well http://www.rasoenterprises.com/propane/ ... l-mixtures Going down to the heading Idle fuel mixture it says and this is how I do it "Once the engine is fully warm, set the idle mixture to provide the highest and steadiest idle speed at the vehicle's recommended idle speed."
Thanks for the reply. I am able to adjust idle speed (RPM) as well with a RPM set screw on the throttle linkage that came with the mixer. So should I remove that screw completely and just use the idle mixture to control the idle rpm to factory spec of 800rpms?? I did notice going from lean to rich on the screw that the idle increases and decreases. Hoping I am understanding that info correctly. Thanks

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6cummins1
Posts: 5
Joined: Thu May 04, 2017 9:08 am

Re: Suzuki Samurai Propane tuning

Post by 6cummins1 » Thu May 04, 2017 4:57 pm

After adding my snorkel system and it seems down on power or sluggish when accelerating how can I get the power back? Is that adjusting the power screw?

storm
Posts: 566
Joined: Wed Jan 10, 2007 10:10 pm
Location: NSW, Australia

Re: Suzuki Samurai Propane tuning

Post by storm » Thu May 04, 2017 10:57 pm

6cummins1 wrote:Thanks for the reply. I am able to adjust idle speed (RPM) as well with a RPM set screw on the throttle linkage that came with the mixer. So should I remove that screw completely and just use the idle mixture to control the idle rpm to factory spec of 800rpms?? I did notice going from lean to rich on the screw that the idle increases and decreases. Hoping I am understanding that info correctly. Thanks
Idle speed screws are there to help the mixer (even carbies and EFI throttle bodies) maintain a certain amount of air flow. If you take the screw out completely the throttle blades will close completely and no air will be able to enter the engine. If you have adjusted the idle rpm screw (the one that moves the throttle plate angle) you will need to adjust both until you get the desired RPM and not further adjustments are required for a smooth idle. I would start by adjusting the RPM screw and trying to put that back to where it was originally, then adjust the mixture screw to obtain the best idle. Once you have done that your idle RPM screw may need adjusting to gain RPM or reduce RPM to the engines intended idle RPM. It will take a little time but adjusting each screw one at a time to achieve recommended idle speed is the way to go. You may have to go back and forth 3-5 times.
6cummins1 wrote:After adding my snorkel system and it seems down on power or sluggish when accelerating how can I get the power back? Is that adjusting the power screw?
There are many variables that could cause this. Do you have a picture of how the snorkel is fitted? Is the snorkel a restriction?
Every job is a self-portrait of the person who did it. Autograph your work with excellence.

Fuel flow requirements calculations viewtopic.php?f=5&t=1638

6cummins1
Posts: 5
Joined: Thu May 04, 2017 9:08 am

Re: Suzuki Samurai Propane tuning

Post by 6cummins1 » Fri May 05, 2017 9:24 am

storm wrote:
6cummins1 wrote:Thanks for the reply. I am able to adjust idle speed (RPM) as well with a RPM set screw on the throttle linkage that came with the mixer. So should I remove that screw completely and just use the idle mixture to control the idle rpm to factory spec of 800rpms?? I did notice going from lean to rich on the screw that the idle increases and decreases. Hoping I am understanding that info correctly. Thanks
Idle speed screws are there to help the mixer (even carbies and EFI throttle bodies) maintain a certain amount of air flow. If you take the screw out completely the throttle blades will close completely and no air will be able to enter the engine. If you have adjusted the idle rpm screw (the one that moves the throttle plate angle) you will need to adjust both until you get the desired RPM and not further adjustments are required for a smooth idle. I would start by adjusting the RPM screw and trying to put that back to where it was originally, then adjust the mixture screw to obtain the best idle. Once you have done that your idle RPM screw may need adjusting to gain RPM or reduce RPM to the engines intended idle RPM. It will take a little time but adjusting each screw one at a time to achieve recommended idle speed is the way to go. You may have to go back and forth 3-5 times.
6cummins1 wrote:After adding my snorkel system and it seems down on power or sluggish when accelerating how can I get the power back? Is that adjusting the power screw?
There are many variables that could cause this. Do you have a picture of how the snorkel is fitted? Is the snorkel a restriction?
Thanks for the reply. That really helped alot! I also noticed while idling that every now and then it will make a popping noise out the exhaust. Nothing loud but its there. I was assuming that has something to do with the idle mixture as well. As for the snorkel I will get a picture. I think the filter may of been restrictive as it was just a cheap cone filter. I ordered a better one to replace it but waiting on it to come in. I made the snorkel out of PVC piping. The ID is the same as the mixer if not a hair bigger. Ill get a picture for you.

6cummins1
Posts: 5
Joined: Thu May 04, 2017 9:08 am

Re: Suzuki Samurai Propane tuning

Post by 6cummins1 » Mon May 08, 2017 11:10 am

Played with it some this weekend. I was able to get the popping out the exhaust to go away at idle by richening the mixture up. I smell the smell of propane now at idle as I didn't before. Not sure if that is normal or not okay? Seems to idle and run alot better. My only concern now is the IDLE RPM screw on the throttle linkage is just about all the way out to get it to idle at correct RPMs. Is that okay? I noticed by richening it up the rpms kept increasing so I had to keep backing that IDLE RPM screw out to compensate.

storm
Posts: 566
Joined: Wed Jan 10, 2007 10:10 pm
Location: NSW, Australia

Re: Suzuki Samurai Propane tuning

Post by storm » Mon May 08, 2017 6:23 pm

Did you follow this advice that I posted previously? "Once the engine is fully warm, set the idle mixture to provide the highest and steadiest idle speed at the vehicle's recommended idle speed."

If you can smell raw propane you are to rich. Being to rich for extended periods of time can cause excessive heat which can, when combined with other factors, cause engine damage. Vapourised LPG is a dry fuel and as such has no cooling effect on engine parts compared to wet fuels like petrol.

Don't worry about popping exhaust to much, it happens with all fuels because no 2 engine cycles are the same.
Every job is a self-portrait of the person who did it. Autograph your work with excellence.

Fuel flow requirements calculations viewtopic.php?f=5&t=1638

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