Logo

Help cant find carb. parts 18 hp merc.

What parts do you need?

1399-8153 (carb rebuild kit), and 1399-8154 (fuel pump rebuild kit) are still a regularly stocked item at Merc.

The kit does not contain the main jet (which is discontinued), but otherwise, unless you smoked the carb body itself there is still alot of parts still available...
 
Yes, that is true.

Tillotson stopped making parts a long time ago. Merc bought up what they could and as they ran out of individual pieces they started "omitting" parts from the kits.

So in this particular case you are really out of luck.

If you can't find anyone with old stock, or a recycler that maybe has an old carb you would be limited to one (kinda radical) solution.

For a touch over 300 bucks you can replace your current carb with a WMC-24 Walbro which Merc installed on the later 18 horse models after their supply of Tillotson's ran out...
 
(this may sound a little convoluted, but it is a retro-fit and not a "direct swap")

The WMC-24 will retrofit to a "rope start" model and a WMC-10 has the linkages for an electric start.

There is one more piece required to convert to the (newer) carb - the carb adapter plate (the Tillotson carbs only had two bolts and the Walbro's have four), but the (Walbro) plate fit's the reed cage (exactly) - this adds about 20 bucks to the refit.

With the plate swap, however, you have to deal with re-jigging the manual choke lever.

(with manual start)

On the Tillotson models, the choke lever installed in a bracket on the carb plate. On the Walbro's the lever is supported by the carb itself and the choke knob on cowl.

If you wan't to keep your original choke lever etc in place (which would save money), you can drill/tap the original carb plate to accept the two extra carb bolts which the Walbro needs - that will not affect it's operation at all - and then fiddle with the alignment of the choke lever to make it work with the new carb.

If it's electric start and you are using a an electric (solenoid) choke activater, then you don't have this issue...
 
Does the adapter plate have a part number? If so, is it available? I want to adapt to the WMC-24.

Thanks again for all your help.

Jim
 
Yep -

The carb (WMC-24) is part number 1390-8888A16 (or 1390-8888A7 - old stock) and the plate is 41420A3 (or 41420A1 - old stock) .

The carb retails for about $320 and the plate is just on $30 bucks. However, you should be able to get a discount on both if you look around on-line...
 
IF you match the model year closely, a 20 or 25 hp carb will bolt right up and produce a bit more power as well. But you have to match the model year carefully, for different year models had different choke set ups and--most importantly--a different pulse hole (for the pump) in the mounting flange.

THOSE carbs are far more common on eBay.

Jeff
 
(this may sound a little convoluted, but it is a retro-fit and not a "direct swap")

The WMC-24 will retrofit to a "rope start" model and a WMC-10 has the linkages for an electric start.

There is one more piece required to convert to the (newer) carb - the carb adapter plate (the Tillotson carbs only had two bolts and the Walbro's have four), but the (Walbro) plate fit's the reed cage (exactly) - this adds about 20 bucks to the refit.

With the plate swap, however, you have to deal with re-jigging the manual choke lever.

(with manual start)

On the Tillotson models, the choke lever installed in a bracket on the carb plate. On the Walbro's the lever is supported by the carb itself and the choke knob on cowl.

If you wan't to keep your original choke lever etc in place (which would save money), you can drill/tap the original carb plate to accept the two extra carb bolts which the Walbro needs - that will not affect it's operation at all - and then fiddle with the alignment of the choke lever to make it work with the new carb.

If it's electric start and you are using a an electric (solenoid) choke activater, then you don't have this issue...

Will this also work for the 1983 25 hp that uses the bc1c carb? I can't find the orginal carb anywhere.
 
The BC1C Tillotson was replaced with either a WMC-11 or WMC-26 (both for rope start models - the electric versions WMC-12/27 is also now discontinued).

Like the above discussion, you would also require a new plate and would have to jury rig the manual choke since the BC1C's choke was supported by the plate and the Walbo's were supported by the cowl and the carb itself...
 
When you get it, compare CAREFULLY the fuel pump pulse hole in both carbs. They MUST line up the same way or it won't work.

Jeff
 
Hi there. I am in the same situation where I need to replace a BC1C Tillotson. Whats the difference between a WMC-11 and a 26? Not sure which one I would need. Thanks for the help!
 
Back
Top