2000 90hp tlry fuel pump diaphram kit

[200090tlry]

I ordered mallory 9-35328 think it fit older 90hp. Everything seems pretty much similar except. Stock unit had clear piece near hole going into motor. I removed black rubber mounted on fuel pump housings. New piece came with grey paper I installed along with center black rubber not clear. I got mallory pretty inexpensive. Pumped it up and bulb gets hard now. Could this be reason I am only getting 4000 rpm when I tested. When rain stops im heading back to lake. Something I should mention when i took the old fuel pump off cracked it open there was no gas in lines or pump. This is good news I think this was the 4000 rpm problem. Motor looks like it has lots hours for 2000 year came from Florida used.

[jb123]

for 40 dollars you should really buy the correct pump replacement

[200090tlry]

Im hoping rodster will chime in

Alot of those parts look same for fuel pumps. Could be my motor is to new have aftermarket diaphram kits. Yamaha gets first dibs to sell parts until motors reach certain age. Rodbolts changed few are there any difference between like older 90hp and 2000 in fuel pump. I checked iboats and dont even list kit, here boats.net I found each piece sold seperate. If im a betting man there are same 40hp -90hp maybe changes 115hp maybe more flexible rubber but same shape? If I am good does the new gaskets have peel tape? Seems old black rubber really on there until i sprayed brake cleaner. Condition of this motor is about as used year 2000 your going to see. I averaged 4 hours a year on my motors everything stayed new. Found some cross references with Mallory set say's replaces 18-7787 yamaha 40-90hp but no year. $5 bucks lol

[robert graham]

Like jb123 said, for $40 for the entire new pump, why not just replace the whole thing?

[rodbolt17]

the pump parts are the same from about the 25 hp up, just the pump body changes.
Yamaha does not offer a kit.
you buy each part.
at 85/hr I simply replace them.
or my customer has a brand new rebuilt pump.

[jb123]

so what youre saying is that you think youve rebuilt the pump correctly and the motor is not running correctly ?

[200090tlry]

Started up motor in driveway

Ran fine with aftermarket parts go figure. Lake test will show really whats up. Im all for ordering a new pump however I need to cut costs somewhere ive got $300 in just gaskets,washers and impeller housings. Saved $35 just wanted to be sure there was not something special about different pumps. Now cant even find Mallory kit. Fingers crossed she will hit 5000 rpm now. Yamaha fuel pumps sure easy compared to Mercury pumps. So twice I needed diaphram kits out of 4 boats guess they do fail and get old. On my Mercury it would pump oil only not fuel the little rubber valve fliped over new kit fixed that problem. When I made my big order for parts I included this kit because id rather have the parts in hand with new to me boat saves weeks shipping time.

[rodbolt17]

ya simply have to remember, on that 2 stroke the pump diaphram moves 10,000 times a minute at 5000 RPM.
they wear out.

[200090tlry]

Did lake test

little more than 4500 rpm maybe 4600 at 36 mph so I picked up over 500 rpm with fuel pump humm. Still should be little higher at 5200 altitude. Ran like crap @ idle stalled out before getting into gear. I had carbs pilot set 1 1/2 turns out like manual, once got to my fishing spot pulled cover and set them 1 1/4 turns and ran all day idled fine. Are all 2strokes fi****y frikers. Im tempted to get factory fuel pump and try that one out before switching to 15pitch k prop. Do you think this makes sense to go 15.

[200090tlry]

Outboards some hardest items to diagnose

We are lucky to have Rodbolt helping us out, thank you! Im going to fill up tank with 91 octane see if there is any improvement in rpms there should not be but who knows if few gallons are 6 year old crappy gas in there. Im putting that 15 pitch on as last resort after looking everything over. Our local gas is 85 octane as regular really makes no sense to me as I do not know any motor that specs anything lower 87octane. And 85 octane is freshest of fuels so I run it in my cars and did put some in boat. Are there any check valves on fuel system I should replace as well?

[jb123]

6 yr old gas you should rid of and clean carbs,replace filters as well