Power drops like a rock at 6,000rpm

[isaac]

My bike has intermittently had this problem since I bought it. It pulls pretty well to 6,000rpm, but then starts making this crackling sound in the engine that almost sounds like detonation, and the power drops off dramatically. I can do a wheelie and once it hits 6,000rpm it sits back down again.

I've fixed this before. After I got sick of it the first time I yanked the tank off and found out it had uni pods on there and stock 138/132 main jets. I cleaned the jets and hogged out the 132 a bit with a screwdriver and the sound seemed to go away and the power came back, albeit temporarily.

I then changed up to 145 jets on both ends with no needle adjustments, and it seemed to work out. It felt so good that I went to the track. I only managed a [email protected], which isn't even close to what it should be trapping, especially considering I weigh about 130lbs, which is well shy of the test riders who've cracked off 100-102mph trap speeds on stock Hawks.

and that drag run was when it WASN'T having the power loss problem up top, so imagine how shitty it is when the problem is present.

So yeah, there's a problem there. Another time I had this problem it wasn't even a fuel thing. The cdi connector had corroded to the point where the bike wasn't charging, and it gave me the exact same symptoms - detonating, major loss of power up top.

I'd added shims under the needles to get some more midrange which was nice, but after a couple weeks the detonation and cracking returned, and it's back with a vengeance. It appears to be getting worse, that is the sound is louder, and the power loss almost like hitting a brick wall.

So, ya know, help?

[PaullyBoy]

If your expieriencing this at wide open throttle try to check and or replace all fuel lines and filters. I had this problem with an old dirt bike of mine turned out the petcock was clogged and so were the filters. If not check your timming.

[isaac]

Thanks for the idea, Paully. I'm gonna head to the dealer today and was gonna pick up some different mains, but I'll also grab a fuel filter.

BTW, I know you have at least UNIs on your bike, and saw your info on jetting and you ended up with about 165/162 mains. Do you have a pipe on there too? Thanks.

[isaac]

I think the conversion to an F2 tank caused the PO to eschew the feature of a fuel filter, because I couldn't find one on the bike. So that's definitely not the problem, since the jets were still clean.

I finally found a socket that would fit inside the spark plug holes, and pulled a couple. To my surprise they were pretty black and were gapped anywhere between .95-1.1mm and the center electrode was worn on both, so they were pretty gone. I'm gonna guess they were originals, or at least very old. The bike has 16,500 miles on it.

I replaced them with the same autolite 4164s that were in there, gapped them to about .85mm (in the middle of the acceptable range) and the bike appears to not be detonating or running out of power up top anymore.

We'll see how that goes.

Thanks to me again for fixing everything myself and then putting a writeup on the board. It'll be a lot of help for mechanically inept lurkers in the future.

[bradrenea]

Thanks to me again for fixing everything myself and then putting a writeup on the board. It'll be a lot of help for mechanically inept urkers in the future.

Ever think that it might be that attitude that kept people from responding? You posted something similar before, and I for one just figured since you are so great you would figure it out yourself.

[LeftRightLeftThrottle]

This is an emoticon of a smiley face with a flame thrower

[isaac]

Thanks to me again for fixing everything myself and then putting a writeup on the board. It'll be a lot of help for mechanically inept urkers in the future.

Ever think that it might be that attitude that kept people from responding? You posted something similar before, and I for one just figured since you are so great you would figure it out yourself.

I see I'm not the only one who thought that was a great quote.

And you're right. But lets look at the impetus for my 'attitude', which you've failed to mention. I've had my bike for about 4 months now, and after the first month I'd seemingly exhausted the helpfulness of a board full of people who've had access to these bikes for nigh on two decades. Just kinda sucks, that's all.

I know you know your stuff, and you're a rare breed on this board - not that it helped me. Here's a tip, Brad. If I'm posting up a thread asking for help, chances are it's because I want help. I'm not sitting here eating cheetos scratching my pale fat ass hoping desperately that my thread just dies so I can go on a tyrade about how this board makes Bimmerforums look like a symposium of Nobel laureates.

You've learned about the bike then actually taken that knowledge and disseminated it online, instead of doing what many on here have done which is to either:

A: come here and not bother learning a damn thing
B: come here, ask a question, have their problem fixed, then leave forever
C: lurk indefinitely, contribute nothing

It's not like you were swamped helping out in the 5 other threads that were active today.

Damn that's good stuff.

[Copytech]

I had to find it.

[isaac]

I had to find it.

Nice. I'd prefer some manner of chainsaw though. You just can't go wrong with a chainsaw.

[Copytech]

OK.


But I found this one more fitting at the moment.



I Am getting these from http://phrozenkeep.it-point.com/forum/smilies_list.php

[jaysun0ne]

hay issac just pretend your a chic then you will get a ton of replys to any post you make.

i help when i can
never done much work on the engine before dam bike just keeps going and going for me. this summer will be my first time rebuilding one. i will be in your boat then.

[bradrenea]

It's not like you were swamped helping out in the 5 other threads that were active today.

Damn that's good stuff.

No, I was swamped working on my race car and building a trailer. I just happened to reply when I was taking a break. And honestly, I did not have an answer, or I would have posted it. It could have been several things, and I did not want to lead someone on several wild goose chases. I have only had my Hawk for six months, so I do not have a wealth of knowledge about them. I do however try to use some of my mechanical skills from working on race cars and wrenching on quads and dirtbikes to diagnose problems with my bike.

[isaac]

hay issac just pretend your a chic then you will get a ton of replys to any post you make.

That's a definite. The internet is magical in that way. Any dude posing as a chick is automatically the most loved member of the board until that terrible day that the lie is found out, and hundreds of members have to burn their clothes and delete their saved chat sessions.

No, I was swamped working on my race car and building a trailer. I just happened to reply when I was taking a break. And honestly, I did not have an answer, or I would have posted it. It could have been several things, and I did not want to lead someone on several wild goose chases.

Sounds a lot like me, including the transference of knowledge from cars to bikes, which sorta works some of the time.

[Hordpower]

Here's the problem Isaac- there are about eleventy-billion things that it could be. To narrow it down a bit, symptoms like yours can occur because:

1) Charging system problem. I know you've checked it, but maybe you better check again. What is the voltage output when you rev it up?

2) Wire harness ground problem. At the rear brake reservoir there is a green wiring eyelet that goes under the reservoir bolt. This gets corroded and all sorts of nonsense starts to happen. Same goes for the battery ground... both ends of it need to be checked.

3) Carb/fuel problem. Could be a cracked or pinched carb slide diaphragm. Could be a plugged filter. You say there is no filter, but! There are two you don't know about, underneath the float valves. You have to pull out the float valve seats to get at those filters. There's a really good chance those are plugged if you don't have an inline filter. There's also a screen inside the tank, on the petcock pickup tube. (should be, anyway)

Now play nice or we'll give you a Schpanking.

[jaysun0ne]

jaysun0ne wrote:
hay issac just pretend your a chic then you will get a ton of replys to any post you make.




That's a definite. The internet is magical in that way. Any dude posing as a chick is automatically the most loved member of the board until that terrible day that the lie is found out, and hundreds of members have to burn their clothes and delete their saved chat sessions.

wow issac sorry i didnt mean to stir up bad memories...