Johnson / Evenrude mid 90s 5/6/8 stoke - Inlet Manifold Photo

[9D280]

In a sentence - anyone got one I could have a look at? (or have one (any HP) they could take a pic of?)

Just to save me taking the whole thing to bits to check out a theory!

Thanks in advance

[Davie]

What you want to know?

[Peter_C]

There are plenty of photos available on the internet. See link below.

https://www.google.com/search?q=1990...w=1280&bih=647

[9D280]

Originally Posted by Davie

What you want to know?

Whether I'm looking to replace it or simply bore / file / cut it out to 8Hp cross sectional area! (Having crawled the parts lists I reckon this "manifold" doubles as a restrictor in the smaller HPs.

Originally Posted by Peter_C

There are plenty of photos available on the internet. See link below.

https://www.google.com/search?q=1990...w=1280&bih=647

Yeah, the exploded pics are OK, but don't show the detail I need!

[bartiny]

I assume that you want to convert a 6hp to 8hp, This might have the info you need, looks like just a carb change? (which is the norm)

Johnson

[9D280]

Bartiny,

In a word - yes. I reckoned that if I'm hanging this on my transom as an aux, I might as well make full use of it's lardiness and have a wee bit extra grunt to spare for that big wind / lee shore scenario....

From the parts lists I've been scouring it would appear to only be the "manifold" and the main jet / carrier need changed. - Makes sense as all the throttle mechanism etc is unchanged, so WOT is WOT W.R.T. the spark, (the "fix it" manual doesn't show any differnet spark advance settings either) and I think all they've done is restrict it with a smaller jet & lump of metal they call "manifold".

[bartiny]

Not sure if this helps.

Upgrade 6hp to 8hp - Johnson Outboard Forum

[slate1234]

I had both outboards a year or so ago, I belive it's only the 1983 model 6HP that can be uprated, the reed valves are diffrent two leaves on the 6HP and three on the 8HP, I did notice the inlet between the carb and reeds on the 6HP was smaller and slightly of set compared to the 8hp, you will also have to adjust the timeing to allow for the larger inlet, the diffrence between the 6 and 8 was not worth the hassel, there is a site "leeroy's rambelings", the guy seems to know his stuff so I emailed him and he told me not to bother, hope this helps.

[9D280]

Ok, its been a wee while since I posted this & the engine has been sitting staring at me every time I go into the garage for the last 2 months. I think some of the replies above may be for an earlier model than mine, as mine is of the 5-6-8 Hp type of (I think) 1997/9 ish but..... tonight I discovered one of the pleasures of buying ex hire stuff!

Under closer examination, the "manifold" looked in better nick paint wise than the rest - so had it been replaced already? a closer look turns out the PN on the "manifold" casting is for the 6HP, and not the 5 the cowl proclaims it to be!

I then find under further examination that the throttle cam follower doesn't appear to be going all the way to the end of the cam - the spark advance plate is stopped a few degrees short of the roller hitting the top of the cam by a big lump of metal poking out the top of the manifold casting. I suspect 5 mins with a coarse file will allow it to go all the way & fully open the throttle. Also explains the one ignition system part number - it's physically restricted rather than electronically, and the power kept down by retarded spark.

I'm off to revisit the manual, as filing off too much will bring it out in sympathy with the Merc...