Carb kits for Merc 7.5 #7106835

[crosbyman]

been looking at carb kits for my winter project   is there a good part #  ex. Sierra  for  a kit

one UTUBE says to use 18-7215 but it is listed for Mercs 40hp +  on Amazon

one kit does not have the  main  nitrile gasket ??   but if I am going to do the carb  I may as well change  all expendables.

btw… funny  2 hose  carb with a pulse pump integrated on the side    where does it get it’s pressure pulses.

I think i’ll have a good runner   120 psi  equal cyl.   good sparks …            .busted skeg 🙁

 

update… looks like Kohler carb 18-7215 carb kitsare identical and much cheaper… Kimpex  canada also has the Sierra it at $17.99  (back-order of course   🙁  )

 

Joining AOMCI has priviledges 🙂

[outbdnut2]

The carb on the 7.5 is different depending on the year and serial number. My Sierra catalog lists a kit #18-7013 for 1969-1973, and no kit for newer ones, but I think the carb with the fuel pump on the side is newer than 1973. At the link below, scroll down to:

7.5 HP
75
Model 75 7.5 HP

At the site, click on all three of the above groups until you find your serial number showing up. I recently went through finding the proper parts for a similar or maybe the same carb you have, and when you get to the parts list for your motor at Marine Engine, and scroll down to the parts list, note that some parts appear more than once if you keep scrolling, with a serial number range listed by the part. I got the wrong float needle that way by not paying attention to serial numbers! There was no complete kit for the 1975 I worked on, but I was able to buy a separate factory fuel pump kit, float needle, and carb gasket kit. Look carefully at the float needle to see if there is a tiny spring in the float end of it – correctly having that spring or not is critical to prevent flooding. The factory gasket kit I got was correct, except for the carb to manifold gasket, which was too big. The float valve seat in the carb I worked on was pressed in and not replaceable.
Dave

https://www.marineengine.com/parts/mercury-outboard-parts/

[crosbyman]

18-7013 is for the  carb with no side fuel pump  ..I am familiar with that carb on my  3.9  and my 4hp Mercs

Thanks for info yet…..the listed kit  for #7106835  is   NLA  …so I ordered  18-7215 since  the pictured parts in the marine.com parts diagram look identical to the kit .

needle wise  I can’t   say   if 18-7215  is ok  so  i’ll just proceed with extra care on the cleaning job… keeping the existing  needle-seat   if what  comes with  the kit  wrong.

I can’t say  I ever had much problems with needle-seat  on my refurbs     a good  cleaning job usually does it . They can clog up  but wear out..???   doesn’t happen much

My local marine shop  has it on order for $18  whereas Amazon is $43 !!!   some were 34$ plus $40 shipping fees .   I actually saw  some 18-7215 kits on NAPA   on sale   $8 cdn  but needed $150 in goods  to have it shipped free…. 🙁

I can wait  and  just do the carb  in January.

Joining AOMCI has priviledges 🙂

[outbdnut2]

Those float needles are new enough to have a neoprene tip, and I’ve had a couple of those (including the one on the 7.5 I mentioned) get to where they don’t seal well when the bowl is full, but yes – usually they are OK. You can always order one later if you need. I’ve found Wholesale marine has some of the best prices for OEM parts.
Dave

[outbdnut2]

My 2004 Sierra catalog shows the 18-7215 kit used only in the 1980 and up 4 cylinder 45 and 50 HP….but like you said, the parts all look right for the carb and its fuel pump. The 45 and 50 HP 4 cyls use multiple carbs, so maybe it’s a similar carb.

It shows 18-7013 for 1969-1973 7.5 HP, and for 1972-1985 7.5s it shows no carb kit, but a 18-7007 carb gasket kit. The gaskets in the 18-7007 look the same but there are more small washer-type gaskets in the 7007 and two sizes of carb to manifold gasket.

18-7057 is a needle and seat for 1969-1972
18-7295 is a needle and seat for 1972-1985, but that is the needle with the spring on one end that was incorrect and didn’t work in the 1975 I rebuilt.

I often find conflicting use listings for Sierra Mercury parts.

Oh – and you asked how the fuel pump gets its pulses. There is a small hole, about 1/8 inch diameter, in the carb to manifold gasket that lets manifold pulses route through a passage in the carb to the fuel pump.
Dave

[crosbyman]

hanks for info … The utube guy  had similar problems with kit parts and ended up using 18-7215… the  neeedle and seat may be bigger ??? for a 40hp but the rest sure looks the same.

 

There is a small hole, about 1/8 inch diameter, in the carb to manifold gasket that lets manifold pulses route through a passage in the carb to the fuel pump.
Dave

thanks… sure is a weird design…. the smaller  “pumpless” carbs on the 4hp are simpler with the usual pulse line design .  I guess that makes one less hose to fail  🙂

I looked at it closer  .. the pump must work on a vacum pulse   on the piston  upstrokes whereas the  other types  (J&E)  work  on  crankcase pressure pulses due to the reeds.

 I’ll mare sure they are cleaned out !

Joining AOMCI has priviledges 🙂

[Author]

Posts