Whats that click in my engine, No compression, Valve stuck open maybe. Options

[DRPHIL914]

52 sounds about right. My reading indicates that I should be running 50s at my altitude (~4300ft). Mine had 57.5s when I bought it and it backfired at idle and at 2500 RPMs. I went down to 50s and it was a bit worse. The idle mixture screws were turned out 10 & 11 turns on all cylinders. I was shocked at that since you're suppose to start at 2 turns out and work your way back in. That hasn't worked on mine. Mine barely runs at 2 turns out. Even with the 65s I'm at 5 turns out on each. I haven't gone further with these jets since I think the less turns out the better. I've checked the points on each screw and they are all very pointed. Maybe this Weber model is different that the others in the way its tuned. I've got 40 DNCF 101-250 4D. They were put on in 88 by the pervious owner.

Anyway back to my original issue.... I found my loss of power after rethreading the intake side of that rocker was the exhaust side blew out. The exhaust valve was not opening and all that heat was going back into the carb i guess. I did notice the carb was unusually hot after my test drive. I didn't think much about it at the time since I hadn't checked the carb temps after other rides to compare it to. I'm probably lucky it didn't start on fire.

I dropped the motor again yesterday and retreaded the exhaust side and put it back in the car. Today I started it up and let it idle for about 15 mins then took the valve cover off and checked the gaps. Looked good so I took it out for a 20 minute easy ride. Power was good and it ran great. Tomorrow I will give it a harder test then check the valve gaps again.

wow well im glad it was not a dropped valve seat, but with 2 of these having issues you might consider re-doing all of them, that just should not happen coming loose or breaking like that, but it sounds like you are getting good at dropping and reinstalling that motor!

[slapshot]

Looks like the engine was “rebuilt” by GEX. Go over to the Samba.com website and check out the Bay Window Forum by searching for GEX engines. GEX is the most reviled engine “rebuilder” on planet Earth. ☠️☠️☠️☠️ is the GEX kiss of death. Start saving money now because this episode is likely the first of many to come.

Thanks for the info. It sure sounds like they are no good. The receipts I have show they bought these heads used. I'll get a better set when I do finally rebuild. Maybe over the winter. Good news, I think, I have verified I do have the original block. Its not all GEX.

[slapshot]

DRPHIL914-- I am now fluent in dropping that sucker (4 times this year so far) and with many other things on this 914. I've never rebuilt an engine yet but that's coming. I'm dying to know what size pistons I have.

[slapshot]

I thought I would give an update here just incase someone else runs into the same issue. I've been going on short drives almost every evening. Engine has been running good. I checked the valve clearances this morning and they were good. No signs that the rethreads are not going to hold.

[porschetub]

52 sounds about right. My reading indicates that I should be running 50s at my altitude (~4300ft). Mine had 57.5s when I bought it and it backfired at idle and at 2500 RPMs. I went down to 50s and it was a bit worse. The idle mixture screws were turned out 10 & 11 turns on all cylinders. I was shocked at that since you're suppose to start at 2 turns out and work your way back in. That hasn't worked on mine. Mine barely runs at 2 turns out. Even with the 65s I'm at 5 turns out on each. I haven't gone further with these jets since I think the less turns out the better. I've checked the points on each screw and they are all very pointed. Maybe this Weber model is different that the others in the way its tuned. I've got 40 DNCF 101-250 4D. They were put on in 88 by the pervious owner.

Anyway back to my original issue.... I found my loss of power after rethreading the intake side of that rocker was the exhaust side blew out. The exhaust valve was not opening and all that heat was going back into the carb i guess. I did notice the carb was unusually hot after my test drive. I didn't think much about it at the time since I hadn't checked the carb temps after other rides to compare it to. I'm probably lucky it didn't start on fire.

I dropped the motor again yesterday and retreaded the exhaust side and put it back in the car. Today I started it up and let it idle for about 15 mins then took the valve cover off and checked the gaps. Looked good so I took it out for a 20 minute easy ride. Power was good and it ran great. Tomorrow I will give it a harder test then check the valve gaps again.

Get your rocker gear sorted and then sort your carbs,those setting you are talking on the carbs are crazy ,when valves are done pull the top of one of the carbs and have a look in the fuel bowl ,if full of crap in the bottom I suspect you have blockages and a full clean and reseal will sort them ,and of course the favorite replies to supply are the following ;
what size vents and main jets,
is your fuel filter good ,
is your fuel tank clean and is the lower suction fuel gauze clean ,
old or new fuel,
what is your fuel pump and running pressure ,
etc as there will be more.
Best to answer the above as it will help you sort them,cheers.

[slapshot]

52 sounds about right. My reading indicates that I should be running 50s at my altitude (~4300ft). Mine had 57.5s when I bought it and it backfired at idle and at 2500 RPMs. I went down to 50s and it was a bit worse. The idle mixture screws were turned out 10 & 11 turns on all cylinders. I was shocked at that since you're suppose to start at 2 turns out and work your way back in. That hasn't worked on mine. Mine barely runs at 2 turns out. Even with the 65s I'm at 5 turns out on each. I haven't gone further with these jets since I think the less turns out the better. I've checked the points on each screw and they are all very pointed. Maybe this Weber model is different that the others in the way its tuned. I've got 40 DNCF 101-250 4D. They were put on in 88 by the pervious owner.

Anyway back to my original issue.... I found my loss of power after rethreading the intake side of that rocker was the exhaust side blew out. The exhaust valve was not opening and all that heat was going back into the carb i guess. I did notice the carb was unusually hot after my test drive. I didn't think much about it at the time since I hadn't checked the carb temps after other rides to compare it to. I'm probably lucky it didn't start on fire.

I dropped the motor again yesterday and retreaded the exhaust side and put it back in the car. Today I started it up and let it idle for about 15 mins then took the valve cover off and checked the gaps. Looked good so I took it out for a 20 minute easy ride. Power was good and it ran great. Tomorrow I will give it a harder test then check the valve gaps again.

Get your rocker gear sorted and then sort your carbs,those setting you are talking on the carbs are crazy ,when valves are done pull the top of one of the carbs and have a look in the fuel bowl ,if full of crap in the bottom I suspect you have blockages and a full clean and reseal will sort them ,and of course the favorite replies to supply are the following ;
what size vents and main jets,
is your fuel filter good ,
is your fuel tank clean and is the lower suction fuel gauze clean ,
old or new fuel,
what is your fuel pump and running pressure ,
etc as there will be more.
Best to answer the above as it will help you sort them,cheers.

I will open one soon and see what it looks like. It could only help to do a full cleaning. I'm going to pickup an ultrasonic cleaner and follow this guys cleaning DCNF Cleaning. Here's what I've got

Venturis: 30mm
Mains: 145
Idle Jets: 65
Airjets: 210
Emulsion Tube: F36

Thanks for the advice.