Evinrude 1998 4 stroke 70hp advice please.

[Jwjsr]

Hey, newbie here, I'm gonna try to fix my 1998 70hp 4 stroke Evinrude/ Suzuki with about 300 hrs myself. Dealer says I need about $1k of fuel system components and that one cylinder is low on compression. It will start with starting fluid but only until it burns out. He and others claim it is my fault for not cranking it monthly which may be true but it sure pisses me off that I can start my 1971 ford tractor after sitting neglected for a year or more. Is this the proper forum for this kind of help. Thanks for reading, JWJ

 

[daselbee]

Your dealer is likely correct. The specific problem is in the high pressure fuel pump, which will lock up if not operated periodically. The low compression is most likely due to leaking exhaust valves. Seen it many times. The two fixes are no small jobs. There are tricks and shortcuts that you can use to reduce the costs of this repair. For example, there is an automotive fuel pump that is an exact replacement for the 350.00 "marine" pumpthat the dealer will sell u. It costs less than 40.00. PM me to discuss in detail.

 

[Jwjsr]

Your dealer is likely correct. The specific problem is in the high pressure fuel pump, which will lock up if not operated periodically. The low compression is most likely due to leaking exhaust valves. Seen it many times. The two fixes are no small jobs. There are tricks and shortcuts that you can use to reduce the costs of this repair. For example, there is an automotive fuel pump that is an exact replacement for the 350.00 "marine" pumpthat the dealer will sell u. It costs less than 40.00. PM me to discuss in detail.

daselbee,
Did you get the PM I tried to send you? New to this forum and not sure how to check if I hit the right button

 

[Jwjsr]

erase

 

[daselbee]

daselbee,
Did you get the PM I tried to send you? New to this forum and not sure how to check if I hit the right button

Nope. Didn't get it.
This forum is broke. (Seems better tho for about two days.)

I will post the info....for the HP fuel pump, you can use a Walbro GCA355 available on EBay here:
http://www.ebay.com/itm/121119240918?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

You will have to cut and paste the link because this site is broke...did I already mention that?
All you have to do is remove the wires and connector from your old pump, and put it on the new one.
Results in about a 300 dollar savings.

Also, you have to remove the powerhead to do a valve job. You cannot get the cylinder head off otherwise.
When the cyl head is off, rotate the cam as necessary to fully close the valves on any selected cylinder.
With the combustion chamber facing up, fill the chamber with mineral spirits. The fluid will leak out the faulty valve seat.

Carboned up, half sticking open exhaust valves are very common. You might avoid this by installing a 160* optional thermostat instead of the 142* standard one.

 

[Jwjsr]

I lost the estimate but remember it also listed "vaporizer". Have the tools but i'm not much of a mechanic. another shop replaced the HP fuel pump about 5 years ago and last shop replaced a sensor on or near the flywheel saying it was most likely cause of engine stalling when pulling back into neutral. Where do i start? replace HP fuel pump first?

 

[Jwjsr]

I lost the estimate but remember it also listed "vaporizer". Have the tools but i'm not much of a mechanic. another shop replaced the HP fuel pump about 5 years ago and last shop replaced a sensor on or near the flywheel saying it was most likely cause of engine stalling when pulling back into neutral. Where do i start? replace HP fuel pump first?

 

[Jwjsr]

Nope. Didn't get it.
This forum is broke. (Seems better tho for about two days.)

I will post the info....for the HP fuel pump, you can use a Walbro GCA355 available on EBay here:
http://www.ebay.com/itm/121119240918?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

You will have to cut and paste the link because this site is broke...did I already mention that?
All you have to do is remove the wires and connector from your old pump, and put it on the new one.
Results in about a 300 dollar savings.

Also, you have to remove the powerhead to do a valve job. You cannot get the cylinder head off otherwise.
When the cyl head is off, rotate the cam as necessary to fully close the valves on any selected cylinder.
With the combustion chamber facing up, fill the chamber with mineral spirits. The fluid will leak out the faulty valve seat.

Carboned up, half sticking open exhaust valves are very common. You might avoid this by installing a 160* optional thermostat instead of the 142* standard one.

Your ebay link shows a cyndrilical shaped pump, I recall the one I had replaced 5 years as being a square rectangular boxed like piece. Does the Ebay one go inside that box, the box is labeled Mikuno or similar, I took pic but it says too large to upload. Sorry, I have like 500 app /programs to solve my upload pics issues but i still haven't figured it out.

 

[daselbee]

OK....not vaporizer...vapor separator.
That is the large silver-gray rectangular odd shape thing right behind the intake runners on the port side.
The HP fuel pump is inside there.

Don't go replacing anything just yet. Do some testing. See if you can install a fuel pressure gauge on the fuel rail. There is a threaded cap at the top that can be removed to attach a gauge, or tee one into the output of the HP fuel filter. You must have 40 psi at the fuel rail.

Replacing the HP fuel pump is much easier than doing the valve work. If you have mechanical sealing issues in the valves, you will not ever get it to run right without doing that job, regardless of the fuel pump....but check the fuel pump pressure. Take it to the dealer, and have them do it for you....you gotta see if that HP fuel pump is working or not. Key on, you should hear that pump go for about 10 seconds, and then shut off. Do you hear it?

The sensor may have been the MAP sensor, ehhh...maybe causing stalling ...maybe not. There is a switch that detects closed throttle, and kinda idles the engine up a bit when coming back to neutral....so it could be either.

 

[Jwjsr]

I would be willing to pay you $100 for unlimited online support to try and fix this whether the result is good or bad. I bkought it in 98 and know the hrs are correct at around 300 or less, it has seen very little salt water, mostly brackish at worst. I live in Fairhope, Ala. Mostly in the bay, the Delta and local rivers. As it took me 3 days to change the Orings on the throttle shaft of the injector pump on my 71 Ford 4000 diesel tractor (prob a1hr job for the trained) I figure you would be in for about 3 or 4 weeks of questions. I can post videos and pics as need be. I look forward to your reply. Thanks WJ

 

[daselbee]

I will try to PM you.

 

[Jwjsr]

Update: With Daselbee's help, I replaced the High pressure fuel pump for $27.00 instead of the $1000.00 the dealer quoted me. This normal 3 hour job took me about a week because I am challenged.
The low compression on #4 magically disappeared. I say magically because it is unlikely the sea foam(actually Gumout) we soaked the suspect valve in fixed it. I think the low compression was more likely due to not running the engine for over 1 1/2 years.
I have done one sea trial and it performed well, no stalls when pulling back into neutral or when engaging reverse of forward.