Johnson 25 To 30 Upgrade

[LukeFishWalker]

New to the forum, so don't flame me too hard for resurrecting an older post.
I just got a 1996 Evinrude E25 REDA which has low hours.
After doing a small amount of research and cross-referencing I want to make sure
I have the correct parts before I start the conversion.
If someone knows more than me, I welcome the advice.

First I needed to be sure the carb was the correct style, manual primer style is what I need.
This is the one I found comparing other 30/35's of the same year with manual primer:

35 Carburetor Part # 0435376 $270.54
http://www.**********/parts/detail/brp/B-0435376.html

The next item is the intake manifold

35hp Intake Manifold Part # 0396790 $118.31
http://www.**********/parts/detail/brp/B-0396790.html

Intake Manifold gasket

35 Intake Manifold Gasket Part # 0326260 $2.82
http://www.**********/parts/detail/brp/B-0326260.html

If there's something I missed, please do not hesitate to tell me,
Thanks

 

[gm280]

:welcome: LukeFishWalker. Great to have you aboard...

If you already did the needed research and comparisons between your 25HP and the 30/35HP engines and know for certain those are the only differences, then have at it. Usually there are difference with port timing and openings and some times even reed valves as well. So make certain you are only needing those parts to turn it into a 30/35 HP engine... Would be sad to spend the money and not get much if any extra ability from it. So I would list both engines and their associated part numbers and check side by side if I were doing this conversion. JMHO!

 

[GA_Boater]

You have a new thread all your own. Waking an 11 year old thread won't get you much. Look at the Hep Tip on top of the page.

 

[LukeFishWalker]

:welcome: LukeFishWalker. Great to have you aboard...

If you already did the needed research and comparisons between your 25HP and the 30/35HP engines and know for certain those are the only differences, then have at it. Usually there are difference with port timing and openings and some times even reed valves as well. So make certain you are only needing those parts to turn it into a 30/35 HP engine... Would be sad to spend the money and not get much if any extra ability from it. So I would list both engines and their associated part numbers and check side by side if I were doing this conversion. JMHO!

Please forgive me as I appear to be the village idiot.
I am a former diesel mechanic, these things are somewhat greek to me.
The smallest thing I work on after becoming disabled is the Snapper Rider.

I compared my 1996 E25 REDA to 1996 SE35REDE.
The leaf plates and leaf valve (Reeds) are in fact identical between these 2 models within the same year.

But, since you brought up timing....I did not consider that aspect of the upgrade.
After a quick search, I do see a part that is HP specific that is different.

Cam, Throttle Control (30 & 35 Only) Part # 326876 $8.26
Again, I feel like the village idiot.
Will this part alone solve the timing difference?

Thanks

 

[gm280]

Luke, the actually timing I was referring to was the actual 2-cycle timing of the engine itself. In other words the time that the piston allows an intake of fuel/air and the opening of the exhaust ports. While the bore ad stroke can be identical, the port time can be different offering more port timing to achieve the extra HP. You can figure that out by comparing the actual engine casings of each. If they are the same part numbers then is would seem the port times would have to be identical as well. So just compare anything that can make a difference between the two HP engines...If all the part numbers are the same, the conversion will work... JMHO!

 

[LukeFishWalker]

Please forgive my ignorance, but is the port timing achieved by way of the block/crankcase itself?
The block/crankcase is identical between the 2 models.
Or is it achieved by way of the By-Pass cover?

 

[LukeFishWalker]

My intentions for the upgrade is not to increase WOT, it's to decrease the time spent getting up on plane.
Here in South West Louisiana we have many shallow water environments with grass & weeds.
The concept is to get up as quickly as possible, then dump the foot on the run to eliminate over heating.

This engine has not been run in over 4 years and currently is just sitting on the boat without a fuel tank.
When I got the engine the fuel pump inlet was broken, the local dealer wants over $140 for an OEM pump.
I'm a patient man so I ordered an OEM online for almost half the price.
Once I get it running (After a good carb cleaning) I plan to start the engine and let it get to operating temperature
and then check the compression before putting it in the water to determine if the conversion is necessary.

This engine is going on a 2006 1642 Alweld (10ga) flat bottom square front tunnel hull.
The hull is fairly heavy compared to other 16' aluminum boats. So, I honestly have no idea how well
this motor will get out the hole with this boat.

I know proping will decrease the amount of time getting up too.
But low end torque is what this engine is known for with the big bore and medium stroke.

 

[jasper60103]

Johny25 has a well documented thread on the upgrade you're planning. It may be helpful...
http://www.tinboats.net/forum/viewtopic.php?f=4&t=23898

 

[pro-crastinator]

I solved my up on plane quicker problem with a hydrofoil bolted on lower unit. worked for me.

 

[LukeFishWalker]

Johny25 has a well documented thread on the upgrade you're planning. It may be helpful...
http://www.tinboats.net/forum/viewtopic.php?f=4&t=23898

Jasper, yes I did in fact read the thread started by Johnny over there.
And I did in fact register at tinboats.
But, unfortunately I have yet to receive an email accepting me as a member.

I got the fuel pump on and replaced all the fuel lines and primer lines.
Pulled the carb and saw that it really only needed to be flushed with carb cleaner and air pressure.
Primed the system and 3 cranks later I was bubbling in the drum.
The tattle tail wasn't draining so I shut it down and removed the fitting on the by-pass plate.
Stuck the hose to it and gently allowed the water to reverse flow into the block.
Some crud came out the baffle/exhaust/drain, that prompted me to remove the plate and baffle.
Cleaned it all out and re-installed the cover and pulled the rope 1 time.
It took about 20 seconds and the tattle tail began draining.
************************************************** ************************************************** *********************
Question:
The fitting on the exhaust cover is 1/8" female pipe threads but the hose is much smaller.
Can I put a 1/8" Male pipe thread X 5/16" hose barb fitting in order to allow more flow and possibly
redirect the tattle tail end which would be closer to eye sight by the tiller handle?
Or, does the tattle tail need to be restricted in order to maintain a certain temp?
************************************************** ************************************************** *********************

A little tinkering with the fuel/air needle and it idled for 15 minutes.
While the engine was warm, I removed the 2 spark plugs and ran a compression test.
135 on top and 130 on the bottom.
I call it a success.

Tomorrow is the test run.
More to come.

 

[LukeFishWalker]

Today I finally found the time to head to the river and try the motor.
The first results were quite encouraging, then it all went downhill after the 3rd time I turned around.
I stayed close to the launch just to be sure I wouldn't have to paddle far.
The motor would accelerate to a point where the power should kick in and start a consistant
spitt & sputter. Idles fine and that's how we were able to make it to the launch.
I'm guessing (Guessing usually makes a fool out of me) it's the high speed jet.
Tomorrow I will take another shot at cleaning the carb out before I order a kit.
It will rev up nicely in neutral just not with a load on it.
More to come.

 

[jakedaawg]

Just a side note here...If that motor has not been run in four years you really should put a new impellar in the water pump. The impellars are rubber and take a "set" over time. While they may still pump it's not the same flow rate as a new impeller. They are easy to replace, inexpensive, and can save a lot of grief later.

 

[LukeFishWalker]

Jake, I do in fact have an impeller and the entire pump ordered and it is scheduled to arrive today.
I was on the water yesterday only about 10 minutes and kept an ever watchful eye on the tattle tail.

I have come to the conclusion that the sponge inside the cowling has begun to deteriorate and
is entering the intake. When I started to clean the carb again I could see many many small black
particles not only in the throat but also some in the bowl. Is it acceptable to fabricate a filter housing
of some sort to prevent this debris from entering the intake?
Or, should I just rip all the deteriorating sponge out?

 

[Tim Frank]

Not sure how the hood lining would get into the carb fuel bowl.
My guess would be that the fuel lines are deteriorating to the point of shedding debris.

 

[LukeFishWalker]

Thanks Tim, I appreciate the comment.
I did not replace the primer pump nor did I rebuild it.
I now believe that's where the contaminants come from.
I had in fact replaced all the fuel lines, the very small line(s) (Primer Pump to carb)
was the hardest to find. I had to actually go to the local marine dealer for that.
To my disbelief, that 3ft' piece of hose was $11.00.
I got 3ft and changed the crankcase bypass/equalizer line as well and had a little left over.
So maybe tomorrow I will find time to do a little more.

Thanks Everyone,
Lukus

 

[LukeFishWalker]

Motor runs fine but could jump out the hole a little better.

After a few hours of crossing part numbers and looking at endless pictures, I think I made a mistake
at first. My engine is the 1996 Evinrude E25 REDA and the matching carb is not the 1996 SE35REDE.
I found the correct carb looking into the 1989 Johnson J35 RCED parts.
As soon as I can scrounge the cash, I am going to get the parts and post an update.
Thank,
Lukus