cwarrior 14 Report post Posted February 21, 2011 Hi, I have a brand new unit-- pressure pro, 3500psi, 5.5 gpm, 18hp vanguard. Runs good at full pressure; however, when using a larger size orifice to reduce pressure for rinsing or using the variable wand, the pressure fluctuates/engine revs. None of or other units does this. What cold be the problem? Thanks, Mark Share this post Link to post Share on other sites
810F250 14 Report post Posted February 21, 2011 something like this Fox's problem was he had a flow type unloader, and the nozzle size was to small it caused the unloader to cycle, once he used the correct size nozzle it stopped. But you are saying the opposite, your nozzle size is bigger and it cycles, humm....... Share this post Link to post Share on other sites
Russ Johnson 141 Report post Posted February 21, 2011 Does choking it a tiny bit stop it from hunting? Share this post Link to post Share on other sites
cwarrior 14 Report post Posted February 21, 2011 Russ, can you explain? Never had this happen with any other untis. If choking a little helps, is there a way to fix the problem? Thanks, Mark Share this post Link to post Share on other sites
Rick2 42 Report post Posted February 21, 2011 I don't know if this might be related but I'll make a comment anyways... My 2 year old snowblower hunts loke a big dog (running lean) to the point that I have to run it at half choke. Here's the weird part; under a load, when you're actually moving the snow, it runs perfect. This started the second season I used it. After researching this I found there are two rubber o-rings in the carb that are dry rotted and throwing off the mixture. Maybe you have a similar problem. Share this post Link to post Share on other sites
cwarrior 14 Report post Posted February 21, 2011 Maybe so. I bought the unit brand new on 2/9. I do not know. Thanks, Mark Share this post Link to post Share on other sites
Russ Johnson 141 Report post Posted February 21, 2011 If choking it a bit smooths it out, the main jet in the carburetor may have debris in it. Was this machine bought from a dealer's stock? Sometimes machines are run when they're received, and if stabilized fuel wasn't used, and the machine sat for a couple of months, you may have a bit of varnish in the carb. If it were me, and the choke smooths it, I'd run a dose of fuel injector cleaner through it and see if it runs better. Share this post Link to post Share on other sites
cwarrior 14 Report post Posted February 22, 2011 Russ, as far as I know the unit was assembled upon my order. I'll check the choke and see what happens. Thanks for everyone's help. I'll update. Mark Share this post Link to post Share on other sites
Doug Black 18 Report post Posted February 22, 2011 Call Rex at Pressure washer products. Share this post Link to post Share on other sites
cwarrior 14 Report post Posted February 27, 2011 Choking it slightly does help. What can be done to fix this? Run a cleaner through the engine? Also, when I turn the unit off, 1-2 sec later the engine pops. What causes this? Thanks, Mark Share this post Link to post Share on other sites
Rick2 42 Report post Posted February 27, 2011 B and S always pop when you shut them down. Even my lawn tractor does it. Share this post Link to post Share on other sites
Shawn F. 14 Report post Posted February 27, 2011 All the new crappy fuel these days RUIN carburetors. I have to deal with these kinds of problems on all of my cars (all I drive are old hot rods) and motorcycles. When the fuel sits in the bowl of the carb it destroys o rings and gums up even within 2 weeks of sitting. Start by checking your spark plug to read how it's running. Then try pulling the bowl off the carb and clean it out and use an air nozzle to blow through the jets. See if that clears up your problem. Share this post Link to post Share on other sites
cwarrior 14 Report post Posted February 27, 2011 (edited) Thanks Shawn, I just bougt the unit last week- brand new. Maybe it sat idle at the manufacturer for awhile. Is there a cleaner that I can run through the engine. I am no mechanic. Also, spoke with a rep at the manufacturer who said some crap about the reason this surging occurs is because the engines are being made to comply with EPA/emissions regulations. As a result, this surging may occur due to the modifications. I don't buy it. Edited February 27, 2011 by cwarrior Added more info Share this post Link to post Share on other sites
810F250 14 Report post Posted February 27, 2011 Choking it slightly does help. What can be done to fix this? Run a cleaner through the engine? Also, when I turn the unit off, 1-2 sec later the engine pops. What causes this?Thanks, Mark Initially I thought it was on the pump end, wrong, but it makes more sense, its the engine. About the engine popping, in the kohler motors manual it recommends the operator bring the throttle to about half speed and then turning off the ignition, not sure if this procedure is useful for the briggs, but when I do it on the 13Hp honda it does stop the engine shut down popping. Share this post Link to post Share on other sites
Russ Johnson 141 Report post Posted February 27, 2011 Also, spoke with a rep at the manufacturer who said some crap about the reason this surging occurs is because the engines are being made to comply with EPA/emissions regulations. Actually, complying with EPA regulations has made a difference over the years. The main jets are smaller so cold running can be a problem. However, after it warms up for a minute or two, it should run properly. Share this post Link to post Share on other sites
Shawn F. 14 Report post Posted February 28, 2011 I wouldn't buy what they said. Try some B12 or Sea Foam. Run a LITTLE bit through the gas tank. It may take 2 tanks of fuel to be ran through to tell a difference. If that doesn't work I would go through the carb or at least pull the bowl off the bottom of it and make sure it's not gummed up. Sometimes all you need to do is drain the bowl, flush it out and run fresh gas through it again. Also for future reference, throw a cheap inline shut off switch at the fuel line before the carb. When you are ready to shut down and will not be using the power washer for a few days, turn the switch to off and let the carb run out of fuel and the engine will die. Now the carb will be dry and no worries of it gumming up. Share this post Link to post Share on other sites
810F250 14 Report post Posted February 28, 2011 Saw this a few months ago and thought it maybe a great educational addition in this thread. Share this post Link to post Share on other sites
Paul Kassander 26 Report post Posted March 2, 2011 I agree try the Sea Foam first and see if ti cleans out the carb. It may be some lacquer like Russ said. Also the governor may need to be reset I have had some Kohler's that needed to be adjusted when we received them. Share this post Link to post Share on other sites
Shawn F. 14 Report post Posted March 3, 2011 Any news on this engine revving problem? Try the Sea Foam yet? I'm curious as to what the problem is... Share this post Link to post Share on other sites
mick m 19 Report post Posted March 9, 2011 I've got a 15 year old B & S that runs as sweet as a nut, but only started back firing on shut down after i cleaned out the carb about 4 months ago. So i've obviously upset something along the way. Share this post Link to post Share on other sites
dmitriy 14 Report post Posted April 11, 2011 If the engine surging and you bought it brand new from the dealer can't you take it back to the dealer and let it be their headache? After all you paid the invoice :-) Share this post Link to post Share on other sites
