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BSE 30 ABC

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Old 10-31-2008, 01:30 PM
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sgilkey
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Default BSE 30 ABC

Hello, I have a BSE 30 ABC. It appears there may have been some slight leakage at the head button/liner area are as the shims are glazed over and there is some goo around that area. I plan to replace the existing shims with new ones. I'd like to "re-baseline" the engine to factory specs in terms of head clearance. The instructions don't say what the "stock" clearance is, or the number of shims. Right now, there are two .002" shims on the button. Can you tell me what the "stock" shims are, or what the target head clearance should be for a baseline setup? Running 15% powermaster.

When I buy a replacement head shim "set" from the factory, can you tell me how many, of what thickness, shims will be included in the "set?"

Also, is a Nelson plug head button available for this engine? If so, should it be set up with the same head clearance as the standard head, for starters?

Thank you.
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Old 10-31-2008, 02:24 PM
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Default RE: BSE 30 ABC

Thanks for writing.....

I will have to check on the deck height. I think the BSE30 is set up around .015.

The head shims vary with each engine. Deck height is what is being set, so each engine may vary with the number and size of shims when it is shipped.

To order the head shims from Dub, note the engine size, approximately when it was purchased, and whether it is side or rear exhaust. There should be a number engraved on the engine too, include that. Include a note on the order form requesting the setup information. He can get you dialed in at the same time.

If the head or existing shims are not damaged, clean the area with alchohol and re-assemble it as is. Make sure the sleeve is properly aligned in the crankcase. After the first engine run, re-tighten the head screws just a bit.

I am not aware of Dub building any of the small engines for use with Nelson plugs. He might be able to fabricate a nelson head for one. Problem is, with the nelson plugs used on the throttled engines.... you end up with midrange and transition issues. They run fine if you are running full throttle all of the time. My personal choice on the BSE30 plug is the K&B HP or a Rossi #3.

Worth noting...... if the head was leaking, the fasteners became loose. The head clamp screws can and do come loose if the engine gets hot while running. So... somewhere along the way, the engine was run lean/hot.

Bob
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Old 10-31-2008, 02:41 PM
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Default RE: BSE 30 ABC

I need to order some other parts like a carb needle, etc. I emailed the Jett2008 address and asked about the shims at the same time as the other parts I'm looking for.

I have not yet checked the deck height, I plan to do that tonight, using the "check at BDC and subtract the stroke" method

The head clamp bolts were snug when I disassembled the engine but it could possibly have been run lean earlier. I am not the original owner. Internally, the engine looks pretty good.

I'll check the deck height and head spacing as currently configured, when I get them measured, and post them here. THanks for your help.
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Old 11-03-2008, 01:21 PM
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Default RE: BSE 30 ABC

OK, I was able to check my engine. It has a "30" engraved on one engine mount lug. I can't find anything else on the engine, or in the instruction sheets, regarding a build date or serial number.

The measurements I took, using a depth mic, are:

Deck height BDC .7235
Stroke (per instructions) .644

=deck height TDC .0795

Head button height .075

=head clearance, no shims .0045

2x.002 stock shims .004

=head clearance, current .0085

That seems pretty low....when I had Jett 40s that I ran for pylon, I seem to recall they were set up around .012-.014" head spacing as a "baseline"???

I have not yet received a reply I sent to the factory regarding clearance, replacement part availability/pricing, etc.

Thanks for any info you can provide.
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Old 11-07-2008, 04:40 PM
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Default RE: BSE 30 ABC

I emailed the factory asking about parts availability/pricing and head spacing and have gotten no reply. Can I get a reply either here, or by email? I'd really like to try to give this engine some flights before the weather goes completely to pot here in Michigan, temps are falling fast, they say snow this weekend (ugh) but there will be a few more decent flying days before winter sets in! Thanks
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