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High RPM's


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#21 banzai510(hainz)

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Posted 12 March 2017 - 10:51 AM

if you have the cheaper thin carb adapter(cast) if one bolts them down to hard they may crack. theya re different versions so Im just guess which one you have . I cracked one and I gave my spare away to anoher guy and he cracked that one. I went with the tall 1 pc unit. on a L16. On a L20 or taller motor the tall aircleaner might hit the hood. They sell a 1.75 in tall aircleaner if needed


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#22 Rocky671

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Posted 12 March 2017 - 11:10 AM

if you have the cheaper thin carb adapter(cast) if one bolts them down to hard they may crack. theya re different versions so Im just guess which one you have . I cracked one and I gave my spare away to anoher guy and he cracked that one. I went with the tall 1 pc unit. on a L16. On a L20 or taller motor the tall aircleaner might hit the hood. They sell a 1.75 in tall aircleaner if needed


Thank u banzai510...I will change out my adapter plate.

#23 datzenmike

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Posted 12 March 2017 - 11:22 AM

Remove and inspect it. It may just be the gasket that's leaking. Or the bolts not tight enough. We're saying that it's only possible the adapter is cracked so you know what to look for.


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#24 Stoffregen Motorsports

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Posted 13 March 2017 - 08:05 AM

The two piece adapters are notorious for coming loose. To keep this from happening, use loctite on the threads of both plates. And then use lock washers on the nuts holding the carb to the adapter.

 

Before you tear into it, put a wrench on the carb nuts and see if they are loose.



#25 captain720

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Posted 07 April 2017 - 06:55 AM

Yeah and the gaskets are super easy and cheap, fixed an air leak on my 4wds last engine that way.

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#26 datzenmike

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Posted 07 April 2017 - 07:59 AM

Gasket leak....

 

I have never seen an intake leak that made an engine rev up. A vacuum leak adds air making the idle mixture lean which would lower the revs. If you engine revs with a manifold leak then you are running rich or with the choke on.... same thing. Added air will make it rev up.

 

Affects idle almost exclusively. It would lean out the idle mixture but as the leak doesn't change with throttle opening and as intake vacuum is highest at idle the leak is much less of a bother as you rev it up.

 

If it affects mid range, the leak is so big it can't idle.


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#27 racerx

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Posted 07 April 2017 - 09:27 AM

I would take out the adapters and lay it flat on a table to see how flat it is. These 2 piece can easily be warped, specially if you tighten too much.  If possible, get a one piece, less prone to leaks.  I would spray some brake cleaner around carb area, specially the adapters and if your RPM goes up, then that's the culprit.



#28 hang_510

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Posted 18 April 2017 - 11:42 PM

Try snugging the nuts.


Won't that make it squeal like a loose alternator belt?

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#29 Stoffregen Motorsports

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Posted 19 April 2017 - 07:49 AM

No, that's tugging the nuts. Squealing only occurs when tugging on their nuts.