Uprating Evinrude/Johnson 10 to 15 HP

[Locozodiac]

What are your thoughts, ideas, experiences on 10 to 15 HP, 2 strokes engine conversions on this brand models? What to change, modify, etc, to uprate correctly ?

Happy Sibbing

[Locozodiac]

No post up to date...Turbo what are your thoughts/experience on this tricky one ?

Happy Sibbing

[Downhilldai]

I seem to recall reading on one of the yank sites (iboats, I think ), that it's quite a big job on the Jonnyrood 9.9 - loads of different parts, despite the basic motor being the same. May be worth doing a search on iboats to see if you can find the thread.

Edit:
Here's a couple of threads
http://forums.iboats.com/showthread....de+9.9+upgrade
http://forums.iboats.com/showthread....de+9.9+upgrade

[Locozodiac]

Originally Posted by Downhilldai

I seem to recall reading on one of the yank sites (iboats, I think ), that it's quite a big job on the Jonnyrood 9.9 - loads of different parts, despite the basic motor being the same. May be worth doing a search on iboats to see if you can find the thread.

Edit:
Here's a couple of threads
http://forums.iboats.com/showthread....de+9.9+upgrade
http://forums.iboats.com/showthread....de+9.9+upgrade

Thanks for imput/links

Already have the answer for this one, was just wondering any thoughts, ideas from Ribnetters users.

Happy Sibbing

[Poly]

Loco - if you already have the answer - you might want to look up the phrase Internet Troll in google/wikipedia

[Locozodiac]

Originally Posted by Polwart

Loco - if you already have the answer - you might want to look up the phrase Internet Troll in google/wikipedia

Sorry Pol, will not waist my precious time with you again, this thread was not intended for you, just for experienced users, mechanics, gurus, etc. If you know the answer post it , or maybe ask your beloved "tech guru" if he knows the answer as well.

If my threads upsets you, as they seem, maybe you have something personal with third world's countries; for your peace of mind as well as mine, don't answer them, seems you take all other's posted answers as granted, you should read, ask, experiment, research better for yourself before posting.

Thanks to John, this is a vey nice online better than a magazine web site to post ideas, share rich experiences unavailable elsewhere with old & new users alike, not a place to waist precious space kniffing each other.

Chau!

Happy Sibbing

PD: Puzzled about “Internet Troll” looked on the Net, sorry cannot be applied to me, happens that it’s my own personal thread, not someone else’s one, but can totally be applied to you as you like to give speculative, out of context, personal brain ideas on many of the huge amount of issues/ answeres posted. Be more technical & practical than idealistic. Are you trying to win “The Rib Net World Post of Records” ?

[Poly]

Loco,

You posted a thread asking a question, to which you already know the answer without disclosing that information, (probably in order to start an argument) - that makes you a troll.

I have nothing against "third world countries". You could be in hampshire, swansea or chicago - you'd still be a troll.

[Downhilldai]

Originally Posted by Polwart

..I have nothing against "third world countries". You could be in hampshire, swansea or chicago ...

Hampshire and Chicago aren't third world, you nobber.

[Poly]

Originally Posted by Downhilldai

Hampshire and Chicago aren't third world, you nobber.

[Locozodiac]

Originally Posted by Downhilldai

Hampshire and Chicago aren't third world, you nobber.

Downhilldai, thanks for the correction, as usual Pol is more lost than a guinea pig at a fair.

The post was placed as a survey only to see the tech level of users, noy planning to start any argument. Next time just for Lord Pol, will place an appropiate Title spacifying if it's a thread, inquiry, information, survey, etc, seems he is the only pissed with my post.

[Locozodiac]

Reading profiles, posts, most Ribnetters are using Yamaha, Suzuki and Tohatsu engines, but least of all EvinJon's, in the portable range, so if any sibber out there wishes to make this tricky uprate to his own engine, this is the correct factory procedure.

Short story:
Bought a brand new second hand Evi 9.9 HP 2 strokes engine including it's service & parts manuals and a OMC 305 strongan sib made by Zodiac in the year 1996. Years latter, sold the OMC 305 changed to larger/wider Quicksilver 330, but retained the 9.9 engine. 3 years ago changed to a Sea Rider 360 much wider/longer than the 330 but in complete doubt as if it would move my 360 properly. Why even try as the sib manufacturer recommended a 20/25 HP engine.

Having the parts manual, ordered the 15 HP cover gasket which sits horizontal between the 2 piece carb assy and a wider 46 High Speed Orifice, the plug through which gasoline passes through inside carb. The idea: to force more air and gasoline intake to the engine, stripped the whole carb down, made the conversion, at ide was ok, but at full throttle trying to plane fast was dissapointing. Lost almost all of it's power.

Under trial & error, tried placing back the original 9.9 horizontal gasket and a 40 intermediate size high speed orifice, this time ok at idle, still dissapointing at wot, ended up placing the original 9.9 high speed orifice which was 36. Performed as usual.

Asked the frustrating conversion issue directly to a USA Evinrude engineer who came down here to train local Evi distributer mechanics. The conversion is: You must change the complete Leaf Plate Assy and the complete carb assy for the 15 HP model. The 15 HP plate has slight wider gas passages intakes and better chrome platted layers on leafs (reed valves) compared to the 9.9 model. The 15 carb has wider air and gas internal passages than of the 9.9. The combination of both and some minor gaskets changed around the plate assy ,will give you a final well converted engine.

Have been reading lately some tech confussions about "you have to change the complete engine manifold" in 2 strokes, 2 cylinder carburated engines, you have to change just the complete internal Leaf Plate Assy which sits in between the engine block and the manifold, being the manifold just a cover lid onto which the carb is bolted to. The same prob too about CD (Power Pack) most share the next larger HP model, 10-15/25-30. Though, will have to check that info out in the spare parts catalog of each engine brand to see if they match.

In my case, having the engine from new, perfectly well maintained and impossible to look for a new 15 decided to go for the conversion, the total cost in USA just in spare parts was $ 220 for the complete carb assy and $ 80 for the complete leaf/reed valve assy, a total astonishing $ 300 including my own hand labor which was free.

Conclussions: Don't go for this triky conversion as will cost a lot, unless you cannot find/purchase a factory new/used 15 HP, you love so much your well kept engine, or plan to fit your next lenght sib with same engine without spending so much on a new one. The converted one has a better final top speed, better hole shot and can transport more weight, mates than before, with same prop.

Bottom Line. Don't ask direct conversion issues to the factory, unless you are a direct distributer, cause will give you back answeres as: It's against the factory policy to uprate engines as a matter of owners security; other users will not know they are conducting a modified engine not stated on the engine cover and could lose boat control.

Happy Sibbing

[Downhilldai]

So you need to change the carb and reed valve on the 9.9 Jonnyrood. What year is the motor - 1996?

[Locozodiac]

Originally Posted by Downhilldai

So you need to change the carb and reed valve on the 9.9 Jonnyrood. What year is the motor - 1996?

Yeap, need to change complete15 carb & reed valve plate assembly, not just reed valves alone, as the 15 plate has slight bigger portholes passages than of the 9.9 model. Is a 1996 RED-10/9.9 short tail model as in the posted pic. Running perfectly updated, much better than when a 9.9 model. A Bit expensive to convert though, Tohatsu engines 25 to 30 & 30 to 25 and hope other brands, converts for peanuts as compared.

Happy Sibbing

[Snowdrggn]

Hi all,
I have done quite some extensive fiddling with the 1985-89 jonrude 9.9/15 engines.
here is a link to a posting that covers a few of you questions:
http://forums.iboats.com/showthread....ight=Snowdrggn
Due to the length I would prefer not to edit an post my entries here.

Cheers,
Snow.
PS: make sure your set up and prop are as close to perfect as possible to get the maximum benefit from your efforts. Also if you use Boyeson reeds, they idle much nicer and seem to start better, but will not tolerate a lean "sneeze", so run your idle mixture a bit on the rich side!

[Locozodiac]

Originally Posted by Snowdrggn

Hi all,
I have done quite some extensive fiddling with the 1985-89 jonrude 9.9/15 engines.
here is a link to a posting that covers a few of you questions:
http://forums.iboats.com/showthread....ight=Snowdrggn
Due to the length I would prefer not to edit an post my entries here.

Cheers,
Snow.

Snow,

Was reading your posts, If not mistaken, the 1996 was the last tech updated 10/15 model , that is, no other technical updates were done after next years models. Both reed valves has plate leaf & shim on top. To convert will need to replace also 2 main gaskets from plate assy, will prob break apart when removed as will be solded with use & time.

Happy Boating

[Snowdrggn]

Loco,
The 96 year may have had the last of the tech upadates. My experience lies with the 87-89 years, which seems to have followed through to 95 as far as the exhaust tuner goes.
We try to use the 89 ignitions as they have the 7000 rpm rev limiter built in (UDL-2 ). I apologise if I mislead anyone.

Cheers,
Snow.
PS: For any given year, go on to the BRP parts site and verify what parts are different, that's what we did at the start of the project.