Briggs Intake

[davbell25413]

445677
0725-E1
070629YC
Briggs 24hp vtwin

Are these intakes known to warp? I rebuilt the carb and doubled up on the gaskets. Its still warped on the intake side of the carb. I see light all the way through it when holding it up to light.

[bgsengine]

Have never seen that myself, yet - nor heard of it - this is the 4-bolt 'rectangular" intake? If so, I do believe the gaskets must be positioned correctly and the spacers installed. I seem to recall that they have a gap *around* the intake to aid in cooling / heat shielding but otherwise sealed... (on the "2-barrel" gaskets) to be honest, I never really noticed that at all myself, since most times the engine started right up and ran fine, so no real reason to look... Matter of fact, It's been very rare to even need to rebuild them in my experience - usually a quick cleaning - drop bowl, drop fuel transfer tube, (making sure to note right and left main jets - they are NOT the same!) , flush it out, run the small parts through ultrasonic, put 'er back together - just some gaskets and o-rings replaced individually - much cheaper than a "rebuild kit" - sometimes, if the manifold itself is clean enough, and carburetor is not badly gunked needing a run through ultrasonic, carb is left bolted to manifold.

[davbell25413]

Its rectangular shaped carbs. The gaskets were installed the way the instructions said to in the rebuild kit. Couldnt find anything on this in the Briggs Intek vtwin manual.

[KE4AVB]

Double check your installation of the carburetor you may have it in backwards with part of it hanging on the intake.

With the intake being made of plastic warpage is always a possibility; although, I have rarely seen it on any small engine. Over the years I seen gears to shrink, warp, and even split into in electronic equipment. You can check for actual warpage by using a known flat piece of metal placed over the area in question. It is the same method that is used check to cylinder head for flatness using a feeler gauge. The only difference is if you use a square or rectangle piece of flat metal you also be check for squareness of all the area at one time; otherwords, if one of the four mounting areas is higher than the rest it will show up easily.

[davbell25413]

Its warped. I could see bow in it before mounting the carb. Gonna try to reinstall the carb to it by the Briggs manual using a torque wrench. Doubt that works but gonna try anyways.

Not sure how true this is but the intake looks used part that was put on by someone else. I saw yellow markings on it from a painting pen or crayon.

[bgsengine]

Not sure how true this is but the intake looks used part that was put on by someone else. I saw yellow markings on it from a painting pen or crayon.

Nah - they'll have those yellow paint pen marks from the factory - production line marks indicating it passed QC inspection or had the studs torqued, or location marks for where to place cable ties that fasten engine wiring harness, and so on. See 'em all the time even on brand new engines.

[davbell25413]

I took this back apart and tightened it the way Briggs manual #273521 said to tighten it. 65 inch pounds on the long torx screws and 45 inch pounds on the nuts that hold the breather on. Got bottom side to seal where the bowl is but the top side still wont seal in the middle where the fuel line sit over top of it. I can slide a piece of a business card through it at the top in the middle.

[bgsengine]

Well, original question was if the intakes were "known to warp" so the short answer would be "no" It is not that common

However, if at some point in time the carb was removed and then installed and overtightened on the bolts , I would imagine it would result in some warpage - same as if it were aluminum.

In theory, it may be possible to remove the intake manifold, remove any studs, and using a plate of glass or some other smooth, hard, non-flexible surface, use wet or dry 300 grit or 600 grit sandpaper and a lot of elbow grease to resurface the intake flat. HOWEVER, considering the amount of time it would take to do so, it'd be far cheaper to just replace the manifold.

[davbell25413]

Ok, I'll replace it. Thanks for help guys.