carb vacum leak on 5.5 what to do?

[dkonrai]

i have a 1962 5.5 model 5524r.
the problem, is that after i rebuilt the carb, i noticed i have a small vacum leak. is it ok to use some sealent (silicone) on the carb to head? the motor ran rough and had no top end. i installed new coils, points, condenser, water pump and impeller. when i put it all together i still had rough idle in slow speed. i shot some carb cleaner at the bas of the carb/head and it died. the assumtion is a small leak. i checked for square and it seems ok. the carb "rocks" on the head. it appears that there is a "gap" between the bolt holes and the head. the gap (small as it may seem) is consistant between the two.
is it ok to use sealent to close the gap??? i tried to double up the gaskets, and it helped but still had leakage.
thanks
dino

 

[crxess]

Re: carb vacum leak on 5.5 what to do?

Are you talking about the Carb base and manifold? You really need to find out what is holding it off.
No good will come from trying to makeshift a solution. Gasket sealer will not hold up to fuel contamination.

 

[dkonrai]

Re: carb vacum leak on 5.5 what to do?

correct the carb base and manifold. i bought the motor used so i dont know the history. the motor is clean and most of it was original. it appears that the base of the carb needs to have some extension or o-ring?? maybe a raised portion off the base of the carb to extend the sealing area?

 

[crxess]

Re: carb vacum leak on 5.5 what to do?

Hang in here. I don't have access to any diagrams that old, but several members are familiar with the model. Someone will chime in on what should be.

Can you post a pic of the carb/manifold?

 

[samo_ott]

Re: carb vacum leak on 5.5 what to do?

Yes, you have to make it level somehow. If something is bent or out of the ordinary maybe jb weld the base to fix it up, but this would be a last resort. Attached is a pic of the intake manifold from an earlier 5.5. They are similar or the same I believe.

 

[dkonrai]

Re: carb vacum leak on 5.5 what to do?

carb,

manifold

both of em

and the motor

hope this helps
dino

 

[samo_ott]

Re: carb vacum leak on 5.5 what to do?

Wow. Excellent looking engine.

Anyway, good photos. Everything looks fine to me. Are you sure the carb it not hitting anything anywhere? It should go on easily and snug right down. Seems odd. I've never had a carb 'rock' on me and yours looks in great shape.

 

[tx1961whaler]

Re: carb vacum leak on 5.5 what to do?

Is the carb hitting on the slotted screw immediately under the intake opening?

 

[R.Johnson]

Re: carb vacum leak on 5.5 what to do?

Did you replace the carb to manifold gasket? I don't see it in the photo.

 

[dkonrai]

Re: carb vacum leak on 5.5 what to do?

i thought that the screw was hitting, but its not. i can visualy see a small gap, maybe 0.10 or so. i didnt gap gauge it, but just a visual.
i have a gasket, but taking it off and on about 6 times, it broke. i am making another gasket....... i gotta do it old school, ball peen hammer.
hey thanks about the comment on the clean motor. thats a good part why i bought it. very original, paint, gaskets, coils (gotta see the old crack ones). it has great compression, but had starting, idling, and cooling problems. the guy i bought it from didnt use it much. i knew it was going to cost some to get it running.
thanks

dino

 

[dkonrai]

Re: carb vacum leak on 5.5 what to do?

this is what coils should NOT look like. i wonder why i didnt have any top rpms..........

 

[F_R]

Re: carb vacum leak on 5.5 what to do?

this is what coils should NOT look like. i wonder why i didnt have any top rpms..........

Points look dirty, greasy and nasty too.

 

[crxess]

Re: carb vacum leak on 5.5 what to do?

Set the carb on a flat surface manifold side down. Check it all the way around. that shoulde tell you if its base is warped.

If it is True, slip it on the mounting stud without a gasket. Hand thread the nuts on snug. Study the point of gap.

If the gap is long it may be a high spot - possible side impact around a stud area.
If the gap is short ie is probable a low point. possibly from someone prying the carb off or using it for support prying on another part.

Once you confirm the carb is true, you could a little filing around the intake to level it.

 

[dkonrai]

Re: carb vacum leak on 5.5 what to do?

crexess,
thanks for the tip. one of the first things i did was checked the carb for square. i set it down over a large mirror to check the carb. it seems to be pretty flat (manifold side down) so it doesnt appear that the carb plate is warped. the manifold side seems ok too. the opening is a little jagged, so i used some emery cloth to smoothen it out a little.
it appears that when is place the carb on the manifold w/o the gasket, the bolt holes (two on the side) fit flush, but there is some up and down play (rocking for e and aft) almost like there needs to be a raised surface somewhere.
do i have to get a new carb?? do they still make them?
dino

 

[wbeaton]

Re: carb vacum leak on 5.5 what to do?

Everything looks normal to me. The cam follower at the top of the carb isn't by chance binding against the underside of the armature is it?

 

[Mr.Stuart]

Re: carb vacum leak on 5.5 what to do?

that stud on the right side don't look quite right, either not enough threads, or off center in the hole or something, is the nut maybe not going on the stud far enough?

 

[samo_ott]

Re: carb vacum leak on 5.5 what to do?

that stud on the right side don't look quite right, either not enough threads, or off center in the hole or something, is the nut maybe not going on the stud far enough?

It could be... or it just might be the photo angle...

 

[dkonrai]

Re: carb vacum leak on 5.5 what to do?

good cal about the stud. ill change the two studs and see if there is a difference.

i tried to use some sealent......................not so good! it made it worse. wish me luck. im off trying to find the gasket today. my backyard gasket (tried to make one myself) didnt work out. i have to buy a small ball peen hammer. its impossible to make a gasket any other way.

this is sooooo messed up. i am so close to having the motor running great.

 

[crxess]

Re: carb vacum leak on 5.5 what to do?

Ball point pen and exacto knife.

Anyone think an oring fitted before the gasket might correct the seal? between the pipe and casting?

Is that pipe projecting out?
Did you try a small straight edge(plastic ruler) across stud to stud?

Tape some 120 grit wet/dry sand paper to the back side of a 3/8 deep well socket. Punch it down over the studs and dress the roughness from around the stud area. Both sides look a bit beat up. (maybe tape a good flat washer between paper and socket)

 

[OptsyEagle]

Re: carb vacum leak on 5.5 what to do?

Is there a chance that your rough idle is actually coming from one of your jets that just might not be as clean as you think?