suzuki 200hp fuel pressure

[johndezman]

after reading many posts about poor performance of various brands of outboards, i'm wondering if i might have a fuel pressure problem as engines seem to start and run well (good compression) just don't have the punch over 4000rpm.<br /><br />if i rig a pressure gauge in my fuel line what pressure should i see if healthy fuel pumps exist?<br /><br />what about a booster pump? i've seen some boats with an electric pump boosting the onboard pump? any opinions?

 

[petryshyn]

Re: suzuki 200hp fuel pressure

never seen your engine.....but...<br />-if pressure is questioned, tee in fuel line down line from fuel pump. check pressure while engine maxed out.<br />-don't know your spec, but most carbed units run 1.5-5.5psi. check manual for spec. and procedure<br />-if pressure below spec, tee in vacuum gauge fuel in line before pump. high reading ( >2HG)means restriction in system from pump to tank. this may hinder fuel pressure as well.<br />-don't forget about the filter!!<br /><br />Your low rpm could be other issues as well....<br />-over-proped<br />-weight of boat<br />-motor alignment<br />-timing<br />-jetting<br />-compression<br />-mix ratio<br />-ski-rope wrapped around prop ....LOL<br />-too many fish close to surface...LOL<br />-the list goes on and on..<br />Gooood luck...<br />

 

[johndezman]

Re: suzuki 200hp fuel pressure

boat is propped to reach 5000-5500 as is. problem is this is a 15" pitch vs 22" that should be pulling. (based on comperable rigs from mfg)<br /><br />boat tops out 35 vs "potential" 50+ (again per mfg)<br /><br />with the 22"s it'll get on plane but top out at 3800. this led me dropping pitch to get the rpm up

 

[johndezman]

Re: suzuki 200hp fuel pressure

what should the fuel feed hose ID be?

 

[johndezman]

Re: suzuki 200hp fuel pressure

ttt

 

[clanton]

Re: suzuki 200hp fuel pressure

Probley 3/8s fuel line, one of your post spoke of 3 filters, are all 3 for one engine? What are the compression numbers? Engine running smooth, all cylinders have spark?

 

[johndezman]

Re: suzuki 200hp fuel pressure

got my notes out on the boat for the actual compression numbers, but 100+ is what i recall. engine runs smooth, using a timing light, each cylinder has spark. static, each coil (all ignition coils - one per cyl as well as the various charging coils up under the flywheel) is within suzuki's specs<br /><br />if i gave the impression of three filters, i appologize, there's one water separator with screw on cannister in the boat for each engine AND the factory filter around the fuel pumps under the cowl. so ther are two on each fuel path, four total for the vessel.<br /><br />had one suggestion this week. suggestion was that since hull is '87 that all fuel line from tank to engine may have swollen internally restricting flow since the addition of alcohol in the fuel. hopefully i'll be able to check this befor ehauling for the season.

 

[johndezman]

Re: suzuki 200hp fuel pressure

ttt

 

[johndezman]

Re: suzuki 200hp fuel pressure

has anyone had any experience with fuel hose swelling internally restricting flow?

 

[johndezman]

Re: suzuki 200hp fuel pressure

couldn't find my notes on board, so since the boat is now home from the marina for the winter i did another compression test.<br /><br />i know this isn't "ideal" in that it was done "cold" rather than on a warm motor, the compressions were as follows:<br /><br />cyl # 1 110<br /> 2 115<br /> 3 115<br /> 4 115<br /> 5 115<br /> 6 112<br /><br />if i recall the suzuki manual correctly they say under 120-100. below that rebuild.<br /><br />my feeling is mechanically this isn't bad for a '87 ! but there's still the apparent loss of top end.