After 25K miles I finally decided to change the plugs on my Nighthawk. I was getting an occasional miss and the plugs had never been replaced since new, so I figured it was time. When I went to remove the number 3 plug I couldn't get the socket to seat. Eventually I found that a bent penny had been wedged between the plug base and the head. Not a good sign. Sure enough, when I extracted the penny and started removing the plug, it did not come out easy. It had obviously been crossthreaded.

Just for grins I tried installing a new plug, but gave up quickly. It got hard to turn and I didn't want to screw it up any worse than it was. It's now leaking compression past the threads and is going to need a repair.

I've been wrenching on my bikes for 30 yrs. and have never had to deal with damaged plug threads, so I'm hoping to tap your experience. Have you used an insert on plug threads (Time-sert, Helicoil)? If so, what did you use and how did it work? I'm trying to avoid head removal and a trip to the machine shop.

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Bikin' John
'93 Honda CB750 Nighthawk

Ouch. I don't have any helpful advice, but good luck on it and let us know how it turns out either way.

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"Dude, women are like Vol-Tron. The more you can hook up the better it gets!" --RvB
Currently waiting on a new hip before I can get a new bike.

If given the choice, I would go with a Time-sert (or similar one piece, locking unit) over a Heli-coil for sparkplug threads. Heli-coils tend to break off the aluminum around the repair and slowly 'unwind' themselves over time, leaving a steel thread-like PIA to deal with. Heli-coils also like to come out with the plugs when removing them next time.

If you are going to do this with the head on the bike, do all you can to keep the chips and filings out of the cylinder by covering all taps and cutting tools with as much grease as you can. Cut a few threads, back it out and clean it off, re-grease it and cut a few more. After it is cut and tapped, turn the engine until the exhaust valves are open on that jug and blow it out three times as much as you think is necessary. Install the chosen repair item and it should be good to go.

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No Witnesses....

Thanks, Buzzz. I was leaning towards the Time-sert too. I've been checking around the local shops to see if I can get someone whose already equipped and experienced with Time-sert tools to do it. I was a little nervous about doing this myself, since I have zero experience, but I just watched Time-sert's "How to" video on their website and it doesn't look that difficult. I may give it a shot.

I already built a cylinder vacuum adapter for my shop vac using some duct tape and a flexible straw. Works pretty good!

I'll let you all know how it goes.

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Bikin' John
'93 Honda CB750 Nighthawk

Between greasing the tools and the vac set-up, you should have no problems, Flynrider. If you can't find a shop who will do it on the bike, even if you can, there's no reason not to do this yourself if you are of a mind to.

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No Witnesses....

Now I remember why I hadn't visited a motorcycle mechanic in the last 25 yrs.

So, I called around all over town looking for a bike shop that will install a Time-Sert in my #3 plug hole. Half the shops didn't want to touch the bike since it was more than 10 yrs. old. Of those remaining, most did not know what a Time-Sert was. Some said if I left the bike for a month, they might get around to figuring it out. Another shop said they'd do a helicoil, but they wanted $500 ( ). How do non-mechanical folks get their bikes fixed in this town??

Eventually I got an email from the shop manager of the Honda shop where I bought the bike (14 yrs. ago). I had told him I was looking for someone to do the insert, hopefully while I waited (it takes less than an hour). He said "no problem" and made an appointment. Success at last!!! Well, I got there and the guy said he would never tell a customer that they'd do the repair while they waited (I still had his email). He said he'd call me later that day. I had no ride, so I took the bus home. By the time I got home, there was a message on the machine. Shop manager said he thought they had the right insert in stock, but they didn't. Turns out he could not find one anywhere in town (it's not like this is a small town either). He said it would take a week. Since the bike was already there and his mechanic actually knew what a Time-Sert was, I just let 'em keep it.

Enough of the gloom and doom. Picked up the bike the other day. It only took 5 days. The repair was properly done and the bike was running fine. The cost was reasonable, actually less than it would have cost me to buy the special tools and do it myself. It's great to be back on the road.

The only downside was that the mechanic apparently tried to help me out by readjusting the idle. The CB750 is notoriously cold blooded and won't idle steady until it is thoroughly warmed up. Of course, I couldn't tell they'd touched the idle until the bike had warmed up. It had always (since brand new) idled at a rock steady 1100 rpm and now it was idling at 1500. This is why I don't like taking my bike to a shop. Something else always seems to get messed up.

Anyway, that's my long tale. Given my experience, I doubt I'll ever try taking my bike to a shop again. It's just too much of a hassle. Throughout this process I polled nearly a dozen bikers at work and it seems no one could give me the name of a shop they would recommend. I was told about plenty of shops to avoid, though. What a sad state of affairs. If a well equipped bike shop with honest, knowlegable mechanics opened up in this town, they could make a fortune.

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Bikin' John
'93 Honda CB750 Nighthawk

I didn't know you were looking for a mechanic down there.
I'd have recommended my buddy Derek. He's got plenty of experience with older bikes and was in the Yamaha class with me. He opened Alley Cat Cycles down there and has been looking for more work lately.

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Have owned - 2001 Suzuki Volusia
Current bike - 2005 Kawasaki Z750S
MMI Graduation date January 9th, 2009. Factory Certifications in Suzuki and Yamaha

Wow his prices are very reasonable! He's got some nice bikes on his website too! Are they his or his customers' bikes?

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2008 Ducati Hypermotard 1100
2006 Kawasaki KLX250S
2004 Honda CBR600RR
2002 BMW R1150R
1996 Ducati 900SS

The KZ1000 and the CB360 on the front page are his. CB is still at home in Pennsylvania, but he rides the KZ daily in Phoenix. He's got it pushing 145 HP on a wheel dyno down there, and it weighs 395 lbs. He bought it running and stock and went from that to what it is now in 2 years of working on it on the side when he had the money.

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Have owned - 2001 Suzuki Volusia
Current bike - 2005 Kawasaki Z750S
MMI Graduation date January 9th, 2009. Factory Certifications in Suzuki and Yamaha

Thanks for the tip! Looks like a reasonable shop. Hopefully it'll be a while before a need a mech, but I'll definitely pass this on to my fellow riders here in town.

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Bikin' John
'93 Honda CB750 Nighthawk