Intermittent Lack of Power

[gzlocal]

Hi guys,

I have an issue here. It seems that on random days my bike is extremely lacking in power. I've had this bike for over 6 months and ridden it as a daily commuter, so I know this bike's potential and its limits, and this is a DAILY, NOTICEABLE DIFFERENCE. This is not a placebo effect. There are no surges or putters or anything of that sort. I have run carburetor cleaner (B-12) through two tanks of gas, emptied and cleaned the float bowl, cleaned ALL the jets, cleaned the air filter, changed the oil, adjusted the chain, checked tire pressure, and I have done two valve adjustments over the span of a month to ensure I did it right the first time. Nothing helps. I've also got a float charger on the battery every few days to ensure a fully charged battery.

I thought it was initially due to the cold weather, as they seemed to go hand in hand. But today it is 60 degrees, and coming in to school I could barely get up the same hill at 45 mph that I can normally comfortably pull at 55, and some days even accelerate up the hill. So I don't think the cold is a factor.

Has anyone else had this problem? It's beginning to worry me that maybe my clutch is slipping at high loads, but I've only got 2200 miles on the bike, so I don't think that's the problem.

Anyone with suggestions please chime in, I'm at my wits end!

-Gzlocal

[gzlocal]

Oh yes, I've also checked my spark plug gap and cleaned it, and checked for vacuum leaks with carb cleaner. I'm running Valvoline Durablend 10w-40 for winter, and I usually run Rotella T6 synthetic 5w-40.

A side note, at high RPM's in lower gears, there seems to be some hesitation. I think the best term for it would be a flat spot in acceleration. I know this is common for the bike, but I'm not sure if this would be difficult to diagnose from a slipping clutch under high load. The bike never revs up as in neutral, so again I don't think it's the clutch, but please correct me if I'm wrong.

Thanks in advance!

-Gzlocal

[Water Warrior 2]

Doubtful the clutch is the problem. A different brand of gas might be the solution or try the same brand if you don't already. Different brands may just give you the unwanted power response as some are not as good as others. You need a top tier fuel for best results. Also can you remember if there was any difference in the clothing you were wearing. Wind drag on material might attribute a bit. Mostly though I would think it is a combo of atmospheric pressure, altitude(SP)temp, humidity and a possible unnoticed head wind. Suttle differences can/will slow down a GZ.

[gzlocal]

Originally Posted by Water Warrior

Doubtful the clutch is the problem. A different brand of gas might be the solution or try the same brand if you don't already. Different brands may just give you the unwanted power response as some are not as good as others. You need a top tier fuel for best results. Also can you remember if there was any difference in the clothing you were wearing. Wind drag on material might attribute a bit. Mostly though I would think it is a combo of atmospheric pressure, altitude(SP)temp, humidity and a possible unnoticed head wind. Suttle differences can/will slow down a GZ.

It's usually very wind-free here on my route to work. My clothing is always the same: Leather harley jacket (no jokes please! :tongue: ) with jeans and riding gloves. Today it was the worst it's ever been, because I had to put myself in a full tuck position to try to maintain my speed going up the hill and it did nothing. Granted, it's a tad bit windier here today due to a front moving in, but it is blustery, not really a head wind. But it isn't just today that the bike does this, it just so happened to be REALLY noticeable today.

I have noticed subtle differences depending on temperature, wind, traffic, etc. But these are seemingly random and feel like I lost 5 hp or something. FWIW, I always run BP gas from a newer station so there isn't likely to be water in the gas from leaky old tanks. And it's not like these symptoms last for an entire tank of gas. It's fine one day, and sluggish the next. Or, even more mind boggling, it can be sluggish on my way to work, then when I leave one hour later, it's fine coming home. :cuss:

[mrlmd1]

Just for the hell of it, try and loosen the gas cap and see if that makes any difference and restores power. The vent in your cap could be partially or completely plugged and creating a vacuum and not let the proper amount of gas flow to the carb. If you hear a hiss of air rushing in or the bike picks up power, that could be the problem.

[Water Warrior 2]

Originally Posted by mrlmd1

Just for the hell of it, try and loosen the gas cap and see if that makes any difference and restores power. The vent in your cap could be partially or completely plugged and creating a vacuum and not let the proper amount of gas flow to the carb. If you hear a hiss of air rushing in or the bike picks up power, that could be the problem.

That may well be the problem. Why didn't I think of that.

[gzlocal]

Originally Posted by Water Warrior

That may well be the problem. Why didn't I think of that.

Yea! Why didn't I think of that! :lol:

I can actually hear it venting when I park the bike or move it after it has been sitting in the sun. I just filled up with gas this afternoon in expectance of the coming price hike on Sunday and there was no hiss. But when it starts to act up I'll be sure to try that. I just fixed a leaking petcock, so through all my testing I'm very sure I'm getting adequate flow, but I would like to remove as many variables as possible. Thanks for the suggestions!

I think another user Geezer had an issue with his bike in cold weather, that may or may not be related. It sounded like similar issues. I'll try to track him down and see if he ever resolved his issues.

[Gz Rider]

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[gzlocal]

No, this hasn't crept up since the petcock issue. It's fine, I checked it running the bike on prime as well, which bypasses that o-ring altogether and it made no difference. I don't think it is a fuel delivery problem. It's been doing this randomly, basically since I purchased the bike 6 months ago. It's just so hit or miss I never really paid any attention to it and it always seemed to rectify itself just from one ride to the next. Just like today, on the way home, it was perfectly fine. Nothing seemed amiss in the carburetor when I had it apart on my bench. Everything seated normally and it was actually quite clean. I was just wondering if anyone had experienced this same phenomena, and had managed to correct it somehow.

I haven't really noticed it anywhere else, because on my daily commute that one hill is the largest and steepest I have to climb. I don't know GZ Rider how familiar you are with the Charlotte area, but the large hill on highway 29 at the speedway? That's the one I'm talking about, which I guess is a bit steep for any vehicle with less than 8 cylinders, but it is a good reference point for measuring my bike's "attitude".

As far as opening the throttle too far to lose power, I can actually attest to the fact that once you run out of throttle on the GZ, you run out. You can open it farther, but you don't go anywhere. That's kind of the situation I find myself in everyday on the same hill, it's just that when it decides to act up, the bike doesn't hold its speed. When running normally, if I run wide open in 5th up the hill, I'll at least maintain the 55mph I started at. When being a little pissy, I just watch hopelessly as the speedo drops to 50, then 45....

I guess my GZ is like my girlfriend. She has her good days, and her bad days. But she's always fun to ride! :curse:

Thanks for the suggestions guys! Lovin' it here!

[Gz Rider]

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