18 hp. Vangaurd starving for fuel when hot

Route 6x6 Discussion Board: Shop Talk: Tech Tips and Q&A section: 18 hp. Vangaurd starving for fuel when hot
Top of pagePrevious messageNext messageBottom of pageLink to this message   By matt435 on Unrecorded Date: Edit

Hi, I have a 1968 argo that I have installed a 18 hp. vangaurd in. I have removed the old two stroke exhaust and housing to let more air come into the engine area, I have also bought a new factory exhaust screen and tip. I have cut the old vent hole to fit the new style vent and exhaust tip. I have routed the exhaust tip outside, but the main exhaust housing is inside. I used a 1999 max IV exhaust. The problem I am having is when I run with the hood in place on a hot day for about 15 min. The engine will starve for fuel. Acts like a vaper lock. I have to let the engine cool down before it will run again. I have a clear fuel filter and I can see very little fuel in it. After the engine cools There is more fuel in the filter. The vangaurd I bought new was for a generator so it did not come with a fuel pump due to the gravity feed on a generator. What I did is copy the factory style buy taking off the valve cover above the starter, drilled the proper size hole and installed a 1/4 " hose fitting, Just like the factory style, Here is where I went different , Instead of paying $60.00 for a factory pump I bought a Makuni single inlet,single outlet, vacum fuel pump, like the ones in a dennis kirk snowmoble cat. I mounted it where the factory pump goes but when I had the problem I felt the pump was hot and moved it and mounted it to my frame. I still have the same problem. But If I run with the hood off it does not vaper lock? I Thought of ducting the engines air intake so it would get cool air? I am not sure if this is the fix? I also have access to a factory style pump I am going to try latter this week, Maybe a factory pump is better? Sory for rattling on, I just wanted you all to have a clear idea of my sitiation, I want to get this dialed in for the new humpry ride. I will be bringing my 1968 argo,1971 starcraft,and my 1993 max 2, Thank you all for any help or suggestions Matt

Top of pagePrevious messageNext messageBottom of pageLink to this message   By swamprat8x8 on Unrecorded Date: Edit

Matt 435
Definately sounds like a vapor lock problem since it is getting hot and running out of fuel. Try putting clothes pins (spring type) along the fuel line, as many as you can get on there. This helps to draw the heat off the fuel line. It is an old hillbilly trick. If that does work then try re-routing the fuel line to get is somewhere where there is less heat. Try to add more vents and maybe a 12 volt fan in your engine compartment might do the trick. Wish you luck!
Swamprat8x8 in MI

Top of pagePrevious messageNext messageBottom of pageLink to this message   By MaxRules (Brandon_price) on Unrecorded Date: Edit

Matt, I think your fuel pump is not supplying the right pressure for the Briggs engine. The pump you got is probably made for a 2-stroke snowmobile engine. I would get the pump that is made for that engine like the new Argos have.
The temp, hot or cold, should make no difference with a properly operating fuel system. Make sure your fuel tank has a vent. Gas going out must be replaced with air coming in.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By matt435 on Unrecorded Date: Edit

Thank you Swamprat8x8, you have a good idea about the fan and rerouting the fuel line. I talked to my brigs dealer today who I have known for a long time. He said my problem is my engine is getting to hot. He said when a vangaurd gets hot it looses almost all of its vaccum pulse off of the valve cover. He said I should defenetly duct the engine so it will get cool air from the outside and duct the heated air to the outside. New argos have this done very well, But it would cost me several hundered bucks to due this. I will make my own duct work and try it. Also the dealer said brigs used to use the metal type fuel pump I have but they switched to the plastic type partly because of vaper locking. I will put a factory pump on also. if you or anyone else has a thought please feel free. I will keep everyone posted. Swamprat8x8 where in MI are you? I live on the IN,MI border near Shipshewana IN and Sturgis MI. Thank you. Matt

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Joe Droit on Unrecorded Date: Edit

Newer argos have heat problems too. Last year at Humphrey there were a lot of argos that had to have their engine cover removed every time they stopped. I asked one owner why he did this and was told that between engine and brake heat it was necessary to prevent vapor lock. He said it did not happen all the time but it was a major hassle when it would happen. Removing the engine cover when stopped was cheap insurance. Good luck Matt.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Henry Pitts (Henry) on Unrecorded Date: Edit

Interesting Thread> I have a '95 max II with the 14hp vanguard. When it gets hot (after steady running of 20 minutes to a half hour) it will quit like you turned the key off. I was told it might be the electronic pack mounted on the right front of the engine by the starter was getting too hot and was cutting out. It sounds is if it might be the fuel pump problem like yours Matt. Let us know if your fix works. Any thoughts on the electrical idea? Henry

Top of pagePrevious messageNext messageBottom of pageLink to this message   By matt435 on Unrecorded Date: Edit

Brandon, Yes the fuel pump I am using is used on two strokes. Maybe this is the problem, I am going to install a factory pump this week, I also have ordered some ducting from Orr,s to help also.My fuel tank is vented. Thank you Joe for your info also. Henry The electrical box you are talking about above your starter is the voltage regulator, I do not belive this would get hot and cause your engine to stall. I will ask my dealer friend about that just to make sure.
Also on another note: due to the age of my argo it it made of abs plastic and someone painted it a long time ago and it is coming off. How should I stripe the paint and what is the best paint to use to repaint it? I was told to use MEK to strip the paint and use Benders vinal flexible paint to repaint it. How can I make the new paint job stick better? Thank you for everyones help. Matt

Top of pagePrevious messageNext messageBottom of pageLink to this message   By SWAMPRAT8X8 on Unrecorded Date: Edit

MATT435 I Live In Monroe MI,SWAMPRAT8X8

Top of pagePrevious messageNext messageBottom of pageLink to this message   By matt435 on Unrecorded Date: Edit

I have the fuel problem solved, It was the $15.00 snowmobile pump I bought from dennis kirk, It must not be designed for a 4-stroke. I put a new factory pump on and have not had problem one. Thank you all for the info. After driving my new blue big foot this weekend it makes me wonder why I have been messing with all of my old machines for so long. Must be the $$$ ? Matt

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Tim O'Keefe on Unrecorded Date: Edit

Matt:
I have been having the same problem with vaporlock etc. It never happened untill my bf was a couple of years old, but now it happens all the time. If I drive with the cover off of the air filter it is fine. I tried shielding the fuel pump with tinfoil, but that didn't work. I think that odg made just enough air intakes for the motor to stay cool, and once you start accumulating leaves in the outside air intake and down by the flywheel, it gets just a little tiny bit hotter and the fuel pump malfunctions. I want to try the closepin idea, but how does it take heat away if they are wooden pins?

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Tim O'Keefe on Unrecorded Date: Edit

The same problem happened to me again today when I went out on my Argo. It started to run bad and then it shut down. I had to let it cool off. I get worrird because I am paralyzed!!! I do carry a cell phone with me though!!! Believe it or not, I used to go out without a winch or a phone!!! I can't believe I was that stupid!!! No I'm afraid even with my cell phone and winch!!! I quess I am just growing old! LOL! I think I am more careful now because I have a new baby boy and I want to see him grow up! I never cared about dying before he was born! I love him so much!!!


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