| Author |
Message |
    
Rick Batt
Member
Username: belfry
Post Number: 10
Registered: 08-2014
| | Posted on Wednesday, October 28, 2015 - 12:07 pm: | 
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My BH 25 ran the season but continues to skip and does not go above half throttle. The compression is 60 lbs (100lbs desired) after lapping the valves. We've cleaned the carburetor several times and replaced the high speed valve, and replaced the spark plug and wire.
Anyone have an idea on what next to try? If like to get new points if someone knows where to get them. |
Roger DiRuscio
Senior Member
Username: solarrog
Post Number: 604
Registered: 03-2002
| | Posted on Wednesday, October 28, 2015 - 12:57 pm: |
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here are some questions for you. Did you grind the valves before lapping them in? worn valve guides will cause missing. how is the piston clearances. Did you install a new set of rings? low compression will cause low performance. A new set of points and condenser is a good idea. |
Rick Batt
Member
Username: belfry
Post Number: 11
Registered: 08-2014
| | Posted on Wednesday, October 28, 2015 - 02:57 pm: |
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The manual calls for 100lbs psi. We did a wet and dry compression tests and both results were 60 lbs.which I think indicates a valve problem. The valves, especially exhaust, were poor. We ground and lapped both. We did not replace the rings. How easy is it to replace the guides? I'm looking into a source for points and condenser. |
J.B. Castagnos
Senior Member
Username: jb_castagnos
Post Number: 1117
Registered: 07-2002
| | Posted on Wednesday, October 28, 2015 - 07:49 pm: |
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How were the valve springs? |
Roger DiRuscio
Senior Member
Username: solarrog
Post Number: 605
Registered: 03-2002
| | Posted on Wednesday, October 28, 2015 - 09:54 pm: |
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Did you reset the clearances on the valve stems, If the clearances are to tight it will affect the compression. |
Rick Batt
Member
Username: belfry
Post Number: 12
Registered: 08-2014
| | Posted on Wednesday, October 28, 2015 - 10:05 pm: |
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After we put the head back on and there was little increase in compression, that question came up. The answer is I don't know. Is there a way to check? |
Rick Batt
Member
Username: belfry
Post Number: 13
Registered: 08-2014
| | Posted on Wednesday, October 28, 2015 - 10:10 pm: |
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Regarding the valve stem clearance, and yes they are adjusted to specs. |
Ernie
Senior Member
Username: ernie
Post Number: 2165
Registered: 01-2002
| | Posted on Thursday, October 29, 2015 - 04:14 pm: |
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On a single cylinder engine Low compression is usually noticed in lack of power not skipping.
What do the points look like. I think clearance is .020 in. The clearance is usually in the mag by the points. However .020 will work fine if there isn't a spec in the mag.
The mag should be a Wico model XH
Points are Wico part number X5996
Cond is Wico part number X5614
I just checked and got a ton of hits on eBay
http://www.ebay.com/sch/i.html?_odkw=wico+xh+points&_osacat=0&_from=R40&_trksid= p2045573.m570.l1313.TR0.TRC0.H0.XWico+part+number+X5996.TRS0&_nkw=Wico+part+numb er+X5996&_sacat=0
http://www.ebay.com/sch/i.html?_odkw=Wico+part+number+X5996&_osacat=0&_from=R40& _trksid=p2045573.m570.l1313.TR0.TRC0.H0.XWico+part+number+X5614.TRS0&_nkw=Wico+p art+number+X5614&_sacat=0
Hope this helps
Ernie |
Ernie
Senior Member
Username: ernie
Post Number: 2166
Registered: 01-2002
| | Posted on Thursday, October 29, 2015 - 05:00 pm: |
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From what I remember about your boat I wouldn't suggest taking the mag off the engine as you can take the cover off the mag and get to the points and condenser.
The BH Palmers can be a pain to time the mag when it is removed. |
Rick Batt
Member
Username: belfry
Post Number: 14
Registered: 08-2014
| | Posted on Friday, October 30, 2015 - 11:54 am: |
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Thanks , I'll take that advice. We are going to pull the engine and grind the valve seats and check the rings. Ordered the points and condenser. Good time to make new shims for the engine bed. |
