There's a hole in my header!

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cancunia
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There's a hole in my header!

Post by cancunia »

Anyone come across this? There's a small (1/8") hole drilled at the lowest point of the header on my Suzuki AE50. At first I thought it was a leak but it looks deliberate. I blocked it with a screw and it now won't start or idle as easily. Maybe it's there as a drain?
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Re: There's a hole in my header!

Post by Meatball »

People have been known to drill hole(s) in the rear chamber of their stock exhausts in search of a performance gain. This practice typically nets no noticable improvement and in some cases hinders the bikeÔÇÖs ability to run at the peak of the manufacturerÔÇÖs intended design.

Other times, holes are drilled to try and remedy running issues caused by other problems like a carbon caked (plugged) exhaust, maladjusted carb, many others....your hole may be the result of a shoddy ÔÇ£band-aidÔÇØ repair done by a backyard mechanic to mask the REAL issue of a poor running condition. This would explain why when you plug the hole, it runs like junk.

Its certainly not a drain hole and should be plugged with a bolt, weld, etc...then investigate why your scoot is having issues.
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Re: There's a hole in my header!

Post by Meatball »

Unless the hole you describe is the mounting point of a missing heat shield. Either way, should be plugged by a bolt..
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cancunia
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Re: There's a hole in my header!

Post by cancunia »

Nope, it's a really small hole and looks to be at the lowest part of the header on purpose. I've put a self tapping screw in for the moment and will get the pipe off to investigate further once I've been through the UK road worthiness (MOT) test. This scoot has not been on the road for quite a few years so has a fair build up of gunk in the pipe and it's quite smoky. I'm fairly sure it would fail the MOT test with even a small amount of smoke coming from underneath.
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Re: There's a hole in my header!

Post by motormike »

Total speculation here: Previous owner likely drilled the hole for reasons only he knows, but likely seeking better exhaust flow.
In doing so, there may have also been some changes in jetting or airbox restrictions.
Now, with hole plugged, tune has changed and you must discern if other factors need to be rectified in order to achieve
an happy engine. MAYBE the "muffler" is somewhat clogged with oil build-up, and the P.O. drilled the hole rather than clean the muffler. Seems likely. Now with hole plugged, engine is struggling to push exhaust. Good luck sir...let us know what you find please... :urban:
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Re: There's a hole in my header!

Post by cancunia »

It's amazing that such a small hole can make what seems to be a major difference in starting and idling, I made no other changes, but it will be quick & easy to check. There is a repair on the header pipe a bit further along toward the muffler, it's wrapped with exhaust repair tape that's set hard, again I need to leave that until the scoot is MOT tested, it's not visible from above and should be fine for the MOT test in any case.
In the meantime thanks for all the feedback folks, it'll be a couple of weeks before I can report back as I want to wait until May to get the scoot tested for using on the road. I want to get some miles on my Honda Vision (Aero) during April too.
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Re: There's a hole in my header!

Post by cancunia »

Seems that plugging the small hole in the header was not causing the problem, it was a coincidence, maybe from tipping the scoot over to get at the header. Things got a bit worse to the point that I had to screw in the idle speed adjuster a long way and still could not get it to idle happily. I took the carb off and found some waxy gunge in the float bowl, the gunge had also got into & blocked the idle jet. From reading around on the Web it seems the waxy deposit is most likely from fuel breakdown, it's odd as I'd flushed the tank after first getting the scoot, so there must have been some residue somewhere in the system.
Anywayz, after a good clean of the jets and another flush of the tank it's all working fine again. Modern fuels eh!
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Re: There's a hole in my header!

Post by motormike »

Thank you sir for that reply.
How are you proceeding ? With hole plugged ?
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Re: There's a hole in my header!

Post by cancunia »

Yeap, I'll keep it plugged for the short term as I don't want the smoke coming out from underneath while it's being tested. After that, I'm not too sure. I think the hole was made to let out water. If I run the engine for a while, oily water comes out of the exhaust so there must be a fair amount lurking in there. Maybe a few miles of running will sort that out too.
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Re: There's a hole in my header!

Post by kuromi »

Best get it tested before the MOT changes on the 20th May :coolcruise:
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Re: There's a hole in my header!

Post by cancunia »

It's a bit smoky for sure but not a diesel!

I was a bit worried about the emissions test but it turns out that 2 strokes & vehicles with less than 4 wheels are not tested for emissions. I went for a test run the other day on private land, it seems to have cleared a lot of the smoke so hopefully a quick Italian Tune-up on the way to the test station will clear up any residue in the can and avoid advisory comments.
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Re: There's a hole in my header!

Post by cancunia »

My AE 50 scoot passed the MoT with no issues, zero comments about smoke but he did tell me that the crank bearings were toast.. I'd always assumed the noise was just normal but he assured me that it was not. So, after reading some helpful stuff on here about crankcase splitting and bearing replacement. I've done the bearings & seals. On the way, I found the piston in the wrong way round so hopefully another problem avoided.
Thanks again to all the helpful people on here, this has to be the best Internet resource for small scoots that I've found.
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Re: There's a hole in my header!

Post by Wheelman-111 »

Greetings:

Glad you got it sorted out. Many of us have "self-taught" case splitting and reassembly, by looking up how others did it. It sure makes it easier!
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Theres a hole in my header

Post by Michaelkit »

Thanks for your reply Lindy, no theres actually no dent left, I can just feel it under the skin. Its not visible and it doesnt hurt when I press it. If I press it and let it go nothing happens, not visible just by looking at it xx
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