Author Topic: K5 vibrates real bad.  (Read 28400 times)

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Offline dirkster

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Re: K5 vibrates real bad.
« Reply #15 on: September 26, 2016, 03:10:17 PM »
 Foxx4Beaver, i'll try and do a leak down test tomorrow to be sure they are sealing. also after running the bike, before i found the bad wire, it ran hot but the plug was wet and black. now that the signal wire isn't getting grounded out on the crank, the bike runs much more consistently at higher rpm and the plug returned to being a darker tan and not wet after riding.   

Offline Foxx4Beaver

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Re: K5 vibrates real bad.
« Reply #16 on: September 26, 2016, 03:27:42 PM »
you're probably good to go now....

but still, a leak down test is always good practice on a fresh rebuild...cause there's always the chance something didn't seal, then you could fry it, and then have the misfortune of tearing it all back down, and spending all that money a 2nd time.
Excuse me, ma'am...but you've got extremely nice legs!!!...what time do they open???                                                                                                               https://www.youtube.com/watch?v=n8tCgN3aryQ

Offline dirkster

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Re: K5 vibrates real bad.
« Reply #17 on: November 09, 2016, 03:45:43 PM »
update, leak down test was helpful there were 2 leaks at the cylinder base, got a new gasket and no more leaks. bike still runs bad. noticed that the exhaust was leaking quite a bit at the cylinder, got new o rings and didn't make a difference the cylinder was actually warn out where the pipe seals and i couldn't get any o-ring to seal right. used a roll of teflon tape on top of the o-rings and no more leaks. i was hoping that that would solve the poor running issues and bad vibration. no such luck. runs well at low rpms very responsive to throttle. once you try to get on it fells very dogish and rough. did a spark check seemed weak but made a 1/4" gap and it still sparked so no weak spark.  hopefully its just down to jetting now. looked up a jetting chart and it calls for a 175 main at my elevation of 800 and average air temp 50f the bike has 62 idle 175 main already. any recommendation for jets. engine work is as follows, wiseco .5mm over piston, sleeved cylinder, full port and polish, v-force 2 reeds, fmf fatty, dg muffler, thin head gasket.

Offline Foxx4Beaver

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Re: K5 vibrates real bad.
« Reply #18 on: November 10, 2016, 05:07:30 AM »
That jetting sounds painfully rich for that altitude.
If it were me...I'd throw in a 58 Pilot to start, then throw in a 170 Main.
What slot is the Needle clip in?

I'm willing to bet, you'll end up having to go even a little more leaner than what I just suggested....but start with that.
Excuse me, ma'am...but you've got extremely nice legs!!!...what time do they open???                                                                                                               https://www.youtube.com/watch?v=n8tCgN3aryQ

Offline Foxx4Beaver

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Re: K5 vibrates real bad.
« Reply #19 on: November 10, 2016, 06:11:46 AM »
Another possibility, not to trash whomever did the port work...but it could be out of whack, and not done properly.
Excuse me, ma'am...but you've got extremely nice legs!!!...what time do they open???                                                                                                               https://www.youtube.com/watch?v=n8tCgN3aryQ

Offline sandblaster

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Re: K5 vibrates real bad.
« Reply #20 on: November 10, 2016, 06:13:51 AM »
Starting high on jetting and working your way down is safe..
We start at the following:
55 pilot  
168  main
Middle on the clip
However, not knowing your porting specs can cause jetting issues.
So, get your pilot dialed in first.
Try a 55 and see how close your idle screw is to 1.5 turns out.
Your looking for 1.5 to 2 turns...
Once the pilot is done, then do wide open throttle chops and check your plug.
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline sandblaster

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Re: K5 vibrates real bad.
« Reply #21 on: November 10, 2016, 06:15:31 AM »
Another possibility, not to trash whomever did the port work...but it could be out of whack, and not done properly.

Exactly what I was thinking when I made my last post.
If you open them to much in the wrong places you will need to go richer... Sometimes a lot richer because you reduced the velocity..
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline Foxx4Beaver

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Re: K5 vibrates real bad.
« Reply #22 on: November 10, 2016, 06:20:29 AM »
Start with a 58 Pilot....as none of us on here know what your specs are. If it still feels sluggish, and blubbery, then go down to a 55 Pilot.....small increments at a time.
Excuse me, ma'am...but you've got extremely nice legs!!!...what time do they open???                                                                                                               https://www.youtube.com/watch?v=n8tCgN3aryQ

Offline umberto

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Re: K5 vibrates real bad.
« Reply #23 on: November 10, 2016, 06:31:03 AM »
I have an 88 in Goliath, and the jetting was very far off when I first fired it up.  I had a lot of trouble getting it to run correctly, and eventually took Foxx's advice and bought a Lectron (which fixed the issue).  Once I had the Lectron on, DoldGuy suggested I check the gasket under the main jet block.  They get pretty ratty and can allow fuel around the main jet, causing issues.  That was what was causing mine to act up.  I found a cheap replacement on eBay.  I would definitely keep messing with your jets, but it might be something to check just to make sure.
Perhaps I have a dirt bike addiction?

03 KX 250/88 KX 525/2017 KX250F - Goliath
17 KX250F/04 KX250
04 KX 250 - Lunchbox's Bike
05 KX 125/144

Offline dirkster

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Re: K5 vibrates real bad.
« Reply #24 on: November 10, 2016, 07:25:53 AM »
just started messing with it put in a 170 main, ran better but was choppy up top. definitely need a smaller pilot jet, idle screw is all the way in and it still needs some throttle to run. had the needle set at 3rd notch. moved the needle position all the way down to see if it made a difference, it ran worse with the needle all the way down. moved the clip all the way to the top and it ran better than it had all month. still too rich though, give it a rev and there is still quite a bit of smoke. going to go get some different pilot jets closes place that sells jets is 26 miles. i believe the sleave job and porting was done by kustom kraft.

Offline dirkster

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Re: K5 vibrates real bad.
« Reply #25 on: November 10, 2016, 07:28:52 AM »
also have 4 br8eg plugs for plug tests and br9eix when i get the jetting figured out

Offline Foxx4Beaver

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Re: K5 vibrates real bad.
« Reply #26 on: November 10, 2016, 07:30:35 AM »
you're on the right track.
be sure you get GENUINE Keihin jets!...aftermarket jets are no good.

I like to purchase from these guys...they're pretty quick with shipping...
http://pjmotorsports.com/
Excuse me, ma'am...but you've got extremely nice legs!!!...what time do they open???                                                                                                               https://www.youtube.com/watch?v=n8tCgN3aryQ

Offline dirkster

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Re: K5 vibrates real bad.
« Reply #27 on: November 10, 2016, 09:10:27 AM »
cycle barn had genuine keihin jets got, 165,168,170,172 mains and 52,55, 58 pilot and a new air filter. putting in the 55 and 168 now.

Offline alward25

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Re: K5 vibrates real bad.
« Reply #28 on: November 10, 2016, 10:52:05 AM »
I have not seen this mentioned yet so let me know if I missed it.

The crank being out of true will cause a lot of vibes.  I would overhaul it and get it balanced, trued and welded.
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Offline dirkster

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Re: K5 vibrates real bad.
« Reply #29 on: November 10, 2016, 11:01:51 AM »
alward, i thought about that a while ago but i just rebuilt the engine 2 months ago. the weird part is that it ran perfectly smooth, on par with my cr250,  for about 3 days then fouled a plug and has been terrible ever since.