Engine Trouble Sudden power loss (solved)


Well-Known Member
Local time
4:27 AM
Jan 5, 2020
The new rings should be close to broken in after a couple of tanks of gas. That hill I used to peddle assist to climb? It climbs without peddling. Compression tested when cold is 92 psi. I don't want to remove the spark plug when hot but if I start the bike too slow on dirt the rear tire skids so I'm sure the compression is higher when hot.

When I took out the chinese plug to do the compression test I replaced it with a NGK BR6HS. It's too long for this head. The electrode tapped the piston and closed the gap. Luckily it didn't cause any damage other than to the plug. Is there a shorter NGK plug for these engines?
Get another compression washer and add it to the one already there, give you a little more clearance.

Mike St

Well-Known Member
Local time
5:27 AM
Jun 16, 2008
Ok, so I will tell you my Hughes Helicopter story:

I was working as a Materials Engineer for Hughes Helicopter in California. One day my boss asked me to go to a meeting of top engineers who were going to discuss the company's first composite main rotor blade for the Army's AAH-64 helicopter.

I walked into the room a little late to see about 20 engineers ready to discuss a drawing of the blade. The Manager of the dept., an older
fellow rolled out the drawing - about 15 ft, since the blade is about 25-30 feet long.

I sat down at the only spot left, near the Manager. He asked for comments. I immediately noticed a serious problem that would lead to failure. I raised my hand and said the bushings intended for embedding in the blade at the root end would not hold out because the only feature to hold them in place was a slight knurl on the bushings (4). I said they would fail because the only thing holding them in place was a glue line
against the knurl.

Then I did something I shouldn't have: I predicted when we put the blade on the test rig it would fail in about 40 minutes to an hour. The Manager
got extremely mad and told me I didn't know what I was talking about and he,
screamed, "The whole blade is a goddamn glue line.......!"

Well after the meeting, my boss told me I would no longer be invited to top engineering meetings at the company.
I was about out the door at the company.

Well, we made the blade in a large matched mold and two weeks later, it was installed on the test fixture, and as I predicted the blade failed and all the bushings came loose and the test was stopped in less than an hour.

SUDDENLY, I was treated as genius and they offered me a small raise. Six weeks later the manager was replaced, and I went on to a different company as a senior materials and process engineer, and the blade was totally redesigned.

The Manager should have opened up my critique for comment by the attending engineers instead of standing
and screaming at me. So much for what goes on at companies!

Moderators Note:
Edited to make the text and sentence structure more "reader friendly"...lol.


Well-Known Member
Local time
5:27 AM
Jan 7, 2022
Reminds me of when I offered to fix the springs on my girlfriends horse trailer $60 in parts... Nope they had a guy' that would fix it... About a year later they brought it into the spring co. I worked at and for $2000 I put new springs on it... Her look was priceless