1989 Suzuki RPM Problem

[wingnit]

Can someone help me diagnose a problem? I have a 1989 200 Suzuki. The problem is that it will not go above 4000 rpm. I have done the following:<br />1)checked the compression 110 lbs per cylinder<br />2)changed all 12 spark plugs<br />3)checked all electrical connections and grounds<br />4)rebuilt both fuel pumps<br />5)checked fuel filter and water seperator, both are clean. fuel is fresh<br /><br />When I first take off it has a great holeshot and while planing it will exceed 5000 rpm for a few seconds...then it just starts to lose power and falls off to about 4000 rpm. Bring the motor to an idle and it has no throttle response...but if you let it idle for a few minutes the power returns. <br /><br />Also noticed that the motor monitor system keeps telling me to check my safety equipment while idling out of the canal and continually states all systems are OK. Are these related problems? HELP...I'm at ropes end..up the proverbial creek without a motor and I want to go fishing!!!!

<br /><br />thanks in advance,<br />Mark<br /><br />------------------

 

[JB]

Re: 1989 Suzuki RPM Problem

Howdy, Mark. What happens if you pump your primer bulb while the engine is "backing down"? You describe classic fuel starvation symptoms. If pumping help brings her back up, check out your fuel tank, fuel pickup, and fuel lines for blockages or air leaks; see if you have a misbehaving anti-siphon valve in the tank.<br /><br />Good luck.<br />JB

 

[wingnit]

Re: 1989 Suzuki RPM Problem

Good Morning JB!<br /><br />Pumping the bulb doesn't make any difference, however I have noticed it seems to not pump up real firm like it used to.

 

[JB]

Re: 1989 Suzuki RPM Problem

Yo, Wingnit. That soft bulb may be indicating trouble with the bulb or fuel lines, or even with that elegant filter/seperator. I would try different hoses, tank to sep/filter, filter to fuel pump, bulb with whichever line it is in. Or you might borrow a "house tank" with filter, from your dealer and bypass your entire fuel supply system for test purposes.<br /><br />Good luck.<br />JB

 

[DanMcK]

Re: 1989 Suzuki RPM Problem

wingnit: I had a similar problem. Debris was being sucked into the screen. Drove me crazy until I pulled the fuel pipe and noticed the screen was dirty. The really neat part was that the motor would run fine slow and then bog down after getting up on plane. I removed the screen and let the junk come up into filter. Then the filters started to clog. After four filter changes things seem to be OK. You might not want to remove the screen, If this junk gets up in the injectors you are in a world of trouble. Get the tank cleaned if neccesary. Hope this helps.

 

[wingnit]

Re: 1989 Suzuki RPM Problem

Rained all day Friday and Saturday.....so couldn't do anything until today. I have now done the following:<br /><br />1) Taken the water seperator out of line<br />2) cleaned the fuel filter again (was clean) <br />3) connected the tank line with the bulb directly to the fuel filter. It pumps up and stays hard.<br /><br />The only thing I haven't done yet is remove the pickup tube from the fuel tank. The tank is plastic (65 gallons) and mounted under the floor. I tried for over an hour to get he fitting loose.....nothing doing! Did find a problem at the connection to the motor. Seems they used some sort of plastic connector and it had a small leak. I guess I will have to borrow a remote tank to eliminate the pickup tube being the problem. Anymore suggestions????? Fixing to pay someone to find the problem or s--t can the motor!!! (heavy sigh)

 

[JB]

Re: 1989 Suzuki RPM Problem

Hang in there, Wingnit. The tougher the problem the greater the satisfaction solving it. Just think how good you will feel when she hums a proper tune again for you.<br /><br />Good luck.<br />JB

 

[wingnit]

Re: 1989 Suzuki RPM Problem

Hey JB and everyone else that has reponded!<br /><br />Took a little break from working on it. Spent a couple of hours cleaning all the electrical connections. Some of them were pretty oily. Just thought it would be a good idea to clean all that and then continue with the problem at hand. Had to stop....storm brewing over the house. I will finish reconnecting the fuel lines and try a remote fuel tank tomorrow. I'll let you know if there is any change. <br />Thanks again for all the help,<br /><br />Mark

 

[DolceVita]

Re: 1989 Suzuki RPM Problem

I'm not a mechanic and know nothing of the particular workings of your engine. I had a similar symptom with an engine years ago and it drove me crazy until I had the engine cover off at dusk while running.<br /><br />Weak electrical insulation (in my case a minute crack at the coil) allowed the spark to jump when a certain RPM was reached. The engine ran fine until 3,000 or so then lost power as if starving for fuel. May not be likely with a more modern engine but it can happen. With fuel starving (if it will run extended time at 4,000) it seems that should just be an upper limit or wall. With spark jump a dynamic changes and rpms decrease or engine even shut down. Good luck. FWIW.<br /><br />------------------<br />Dolce Vita

 

[wingnit]

Re: 1989 Suzuki RPM Problem

Howdy all! Finally got around to working on it again and replaced all fuel lines; connected it to remote tank and it worked. So,found that the problem was in fact the fuel line from the main tank. Blew back through the pickup tube and all seems to be well now. Another problem we created while working on it was darn near running it out of fuel(gas gauge is incorrect to boot). Just gonna hafta keep the tank full! Of course running it low on fuel made us think we still had additional problems. I can go on and on... but I won't. Just wanted to say thanks to all for the suggestions along the way! --Mark

 

[DanMcK]

Re: 1989 Suzuki RPM Problem

Wingnit: Glad to hear you found the problem. Do not forget that just because you blew air thru the screen that the junk wont come back up and clog the screen again. If you work on your fuel gauge sender ya might want to siphon some of that junk from the bottom of the tank. Be carful when working with Gas especially below deck where electric could cause a spark. Good luck.