Chrysler 115 Tilston Carb Help

I have a 1979 Chrysler 115. It seems when I try to look up a carb kit for this engine, every body I check on there parts list skips this series of engine. It has a Tilston "TC" D carbs with pressed in neddle seats. The Carbs are a bit Larger than the one I had on my 105. Could anybody could give me a bit of history on this series of 115 engines. I think they only were made between 1978 to 1980.

Re: Chrysler 115 Tilston Carb Help

Kit is an FK10103 merc sells them as well as other after market places. 1977 chrysler 115 used a different kit that was FK10005. Looks like force stayed with FK10103 kit and used it on the 125 HP models as well. The kit goes for $38

Re: Chrysler 115 Tilston Carb Help

My clymers manual shows the 115 being manufactured from 1977 to 1984 with the early Force 125 being a redesignated Chrysler 115. That being the case, the 115 would have a 3.3125 bore and a 2.875 stroke versus the 105 having a 2.80 stroke. However, I seem to remember the 115 as having a 2.80 stroke and a 3.375 bore--could be wrong though; the memory is the second thing to go!

See: Chrysler made four series of blocks. All were the same block but the 105 was 2.80 X 3.3125 for 99 cu in. The 115 (If I remember correctly) was 2.80 X 3.375 for about 103 cu in. The 125 was 2.875 X 3.3125 for about 102 cu in. and the 140 was 2.875 X 3.375 for 104 cu in.

The TC carbs being 1 5/8 venturi diameter are way larger in area than the 1 5/16 diameter WB carbs on the 105. This, the extra cubic inch(es), and port timing accounted for the horsepower increase over the 105.

All TC carbs are basically the same casting with minor differences in jetting, venting, and low speed needle placement. Early Force TC carbs had a nipple in the bowl bolt to enrich starting mixture. later TC carbs also had enrichment nipples in the flanges to replace the choke. The different jets and nipples may account for the different part number of the rebuild kit.

Re: Chrysler 115 Tilston Carb Help

Thanks guys for the help. Is this power head one of the better Chryslers? It seems to run good.

Re: Chrysler 115 Tilston Carb Help

All the powerheads are good. They are all the same casting with different bores and strokes. All related equipment is the same too. The one weak area was the Magna-Power II ignition which failed regularly. The 115 was never manufactured with Mag-II so there is no worry there. As a 1979 engine, you probably have Prestolite distributor-less electronic ignition. If so, timing is a bit more steady than distributor engines thus a bit less maintenance and a bit more power--not a lot, just a bit. Either ignition system is good and functions well though. My 90 and 140 both have distributors while my Force engines all are non distributor engines. I have no complaints with either.

As a 1979, you may have either the two piece lower unit or the one piece lower. I have been told they changed in 1979 1/2. Both are good but the one piece has several advantages and is engineered a little better.

The two piece lower unit has an 18 (I think) splined prop shaft but the prop is located with a 5/16 pin in the front of the hub. This pin is held in place by the tailcone. I never did like that 5/16 pin taking all the thrust, but I have never had one fail yet. On my two piece, when I use a prop with room in the back, I clamp a stainless split collar on the shaft behind it and let that take the thrust.

Big disadvantage to this lower unit is that if you need a prop, you must hunt for one. As far as I know, no one makes props for this lower any more.

The one piece lower unit has a 15 splined prop shaft, but the prop is located by a thrust washer behind it and inside the hub. The gearcase is much longer than the two piece gearcase and just looks more "elegant." Water pick-up on the one piece is on the side of the gearcase right behind the prop hub. It is lower than the pick-up of the two piece for more positive water flow.

The two piece lower unit is one inch longer than the one piece from engine clamps to cavitation plate. Engines with two piece lower units can usually be run one inch higher on the transom.