[mo84]

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so I over reved my bike the other day when I started it and now when I ride, it almost feels like it is missing butit isntso im thinking either a valve went or the valve is way out of adjustment now. the bike still runs decent but doesnt have its normal power like beforeI over reved it and it dont even sound quite the same. so what do you guys think.



also is there a way to see if it is a bad valve without taking the head off?

 

[GregForesi]

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A compression check should give you some idea if a valve is hanging open.
When you say "over-rev" how far did it go? I've seen the videos of the guys running blowers and the bikes pick up revs so fast they blow through the redline all the time. I think mine has seen 9500 a couple of times (missed shifts).

 

[mo84]

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I maxed it out and as soon as I put it in gear it started running like I explained, so I know the two coincide with eachother. ill have to get my cousins compression gage then. thanks

 

[Ken Bergen]

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Do a compression check to make sure but it sounds like you floated the valves and tapped them with the pistons bending them.

Did you by any chance run it to the red line then shift down instead of up?:shock:
That was a common problem in the early 80's when the ATV's of the time had a reverse shift pattern, up for a lower gear down for a higher one. Ride your ATV one day and your bike the next day and damn another bent valve.

 

[mo84]

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thanks. no the bike was in nutral when i over reved it as it was being started. would it hurt to ride it the way it is right now or would it make things worse

 

[machinehead]

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Gee mo , how do you overrev a bike at start ...?
Ok ., if you pinned it right after starting when all the oil was still in the pan , you have probably hurt the motor ., if you pinned it just after start a vacume test first off should show a bad valve and a latter compression test will show any other nasties.

 

[mo84]

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had the throtle all the way and hit the start button is how.

 

[Ken Bergen]

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mo84 wrote:

thanks. no the bike was in nutral when i over reved it as it was being started. would it hurt to ride it the way it is right now or would it make things worse

If one or more valves are bent don't ride it. The bent valves would be junk of course but if you ride it the leaking hot gasses can cut into the valve seat costing you much more.

 

[mo84]

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thanks for all the replys guys, looks like i got some work ahead of me

 

[Dirt Road Cowboy]

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Mine started doing something similar. This past weekend, I was checking the charging system, and tested the battery with the engine revving at 5000 RPMs. I was getting over 13.5v and slowly climbing.

The next day though, I had a hard time starting her, and when I did get her running, she was popping through the exhaust, stumbling and has no power.

I thought that maybe I just had a clogged gas filter, but I hope it isn't anything worse! I've had her over 5K RPM on the road, but never just sitting and revving.


:?

 

[sctrucker]

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when i lost a belt and bent a valve on my first GL1,000 i put another set of belts on it and rode it toward a friends house who worked on goldwings since it didnt return to idle like it had been before the belt broke, i made it about 5-10 miles before the bent valve broke and took out the left side of the motor

 

[Ken Bergen]

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dsmastern wrote:

I thought that maybe I just had a clogged gas filter, but I hope it isn't anything worse! I've had her over 5K RPM on the road, but never just sitting and revving.


:?

Something to consider is that the tachometer is mechanical and can lag a lot. If you open then close the throttle with no load and see 5,000 on the tachometer the engine could have actually reached double that or more.:shock:

 

[Dirt Road Cowboy]

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Ken Bergen wrote:

dsmastern wrote:

I thought that maybe I just had a clogged gas filter, but I hope it isn't anything worse! I've had her over 5K RPM on the road, but never just sitting and revving.


:?

Something to consider is that the tachometer is mechanical and can lag a lot. If you open then close the throttle with no load and see 5,000 on the tachometer the engine could have actually reached double that or more.:shock:

It was a slow RPM increase so that I could test and see if there was a voltage increase to the battery. I never went over 5500 RPM.

 

[Broke Winger]

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A quick easy way to check for a bad valve is to hold a dollar bill in front of the exhaust pipe while it's running. Do one side and then the other. The exhaust should push the bill away, if you have a bad valve it will alternate between pushing the bill out and trying to pull it in.