dklawson
Yoda
Offline
This post does not directly involve a Spridget but it does involve SU HS series carbs. I want to ask the question here to see if anyone has ever seen what I found yesterday.
My sons drive a '72 Triumph Spitfire. The car was originally outfitted with a single Zenith Stromberg 150-CD2 carb. I don't like those carbs so I replaced it with a single SU HS4 from a Mini. The SU HS4 swap is fairly common for the later Midgets that use the Triumph engine. The float bowl for the HS4 carb is also the same as used on the HS2 carbs used on earlier A-series Spridgets.
Yesterday I moved the car and smelled a lot of gas. Opening the bonnet I found fuel all over the engine bay. I ran the electric pump and watched for leaks. Fuel was pouring out of the bottom of the carb. I thought it was the rubber seal between the float bowl and jet tubing.
My diagnosis was VERY wrong. It was not the jet tubing. It was not the float valve. It was the float bowl itself. The float bowl had cracked from bottom to top on both sides of the bowl's mounting boss allowing huge gaps to open in the walls of the bowl. I had a junk carb to get a replacement bowl from. I noticed the replacement bowl was from an older carb and the casting was much thicker and heavier than the later bowl that failed.
The broken float bowl was never bumped, knocked, or dropped by me. I did buy this used so I don’t know the history behind this carb. However, I have never seen such a failure. The purpose of this thread is to ask... have any of you seen this before on your Midgets or on any other car equipped with HS2 or HS4 SUs? I'm just thankful my sons were not cruising around somewhere when the float bowl let go. It could have been a very unhappy father's day for me.
My sons drive a '72 Triumph Spitfire. The car was originally outfitted with a single Zenith Stromberg 150-CD2 carb. I don't like those carbs so I replaced it with a single SU HS4 from a Mini. The SU HS4 swap is fairly common for the later Midgets that use the Triumph engine. The float bowl for the HS4 carb is also the same as used on the HS2 carbs used on earlier A-series Spridgets.
Yesterday I moved the car and smelled a lot of gas. Opening the bonnet I found fuel all over the engine bay. I ran the electric pump and watched for leaks. Fuel was pouring out of the bottom of the carb. I thought it was the rubber seal between the float bowl and jet tubing.
My diagnosis was VERY wrong. It was not the jet tubing. It was not the float valve. It was the float bowl itself. The float bowl had cracked from bottom to top on both sides of the bowl's mounting boss allowing huge gaps to open in the walls of the bowl. I had a junk carb to get a replacement bowl from. I noticed the replacement bowl was from an older carb and the casting was much thicker and heavier than the later bowl that failed.
The broken float bowl was never bumped, knocked, or dropped by me. I did buy this used so I don’t know the history behind this carb. However, I have never seen such a failure. The purpose of this thread is to ask... have any of you seen this before on your Midgets or on any other car equipped with HS2 or HS4 SUs? I'm just thankful my sons were not cruising around somewhere when the float bowl let go. It could have been a very unhappy father's day for me.