New F80 motor is running rough

MitchP · Jun 1, 2013

I bought an F80 from dax. I've got an NGK 7 plug and an RT carb. The fuel I'm using is 91 octane, 20:1. At low speeds the ride seems choppy. At first I had a .65 jet in there and swapped for a .7 and that made it a little better, but the bike has a lot of vibration and it's choppy at low speeds. I also noticed that every component attached to the motor seems to heat up, which I did not notice on my last kit.

biknut · Jun 1, 2013

If it has a NT carb, put the needle clip in the second slot from the top.

A B7 is kind of cool. Try a B6HS, and BP6HS. Gap to 0.025"

MitchP · Jun 1, 2013

Ok. I've a got a 6 laying around and I've been setting them to .035/1000". So I'll add the 6 and shorten the gap. It's been in the 70-80F temp range lately.

maniac57 · Jun 2, 2013

Give it a few miles to smooth out. All of my recent builds have been tighter than usual. I think(hope) the quality is trending upwards. Tuning is better left until a couple hundred miles when things settle in. The heat issues can also be caused by a tight, fresh engine.
Once it has a few miles it will smooth out quite a bit. Mine usually take three or four tanks minimum to fully break in.

MitchP · Jun 2, 2013

Yeah I just don't remember the first being as choppy. I tried the Ngk 6 and the 7 set to .030 and the 7 was the winner. Would you guys recommend buying 87 octane? I think it could be 4 stroking a little.

MitchP · Jun 2, 2013

It's smoothed out actually. I forget that my first build was a complete P.I.T.A.
To do list: buy 87 octane, mix it. Get a torque wrench, set heads to 12 (ft pounds?).

biknut · Jun 2, 2013

MitchP said:
It's smoothed out actually. I forget that my first build was a complete P.I.T.A.
To do list: buy 87 octane, mix it. Get a torque wrench, set heads to 12 (ft pounds?).

That's the wrong torque wrench. Get a torque wrench that reads in inch pounds. I torque my M8 head bolts to 125 in lb.

BigBlue · Jun 2, 2013

Here's a guide that will help you. I keep it bookmarked, so I don't have to ask:
https://docs.google.com/document/d/1GcesQihc7-mm3hJGf7UPiqOaRXZ8ekUT99QUZq2qXXE/edit

Chris
AKA: BigBlue

MitchP · Jun 7, 2013

I packed red grease into the clutch actuator and between the bucking bar and bearing. It's a lot quieter now that it;s got some miles on it too. Should I pack grease into the clutch too? Like unscrew that bolt and pack it in?

crassius · Jun 7, 2013

it's sealed at both ends, so shouldn't need it - I doubt it would hurt anything tho

fatdaddy · Jun 7, 2013

Yeah, A little grease on the big clutch gear and the small bevel gear. Just a few dabs, It will spread itself around. And don't get any on the pads for obvious reasons. It's a metal to metal gear, OF COURSE it needs a little grease. And I always pull out the bucking bar, shove grease in the hole and push the bar back in. Then I pull out the clutch lever and grease it up too. Anything thats metal to metal needs grease.
fatdaddy.
And OH YEAH, If ya get ambitious, pull the clutch plate and you'll see the tiny bearings in the clutch itself. TRY to get a little grease in there too. Sometimes I just drop a little heavy oil,(50-60wt.) into it. Again, it's metal to metal, Needs lube. Just a drop or three, too much will spin it back on the pads. oil+pads=BAD.

maniac57 · Jun 7, 2013

MitchP said:
I packed red grease into the clutch actuator and between the bucking bar and bearing. It's a lot quieter now that it;s got some miles on it too. Should I pack grease into the clutch too? Like unscrew that bolt and pack it in?

If you pack this area, grease can work it's way past the bearings enough to contaminate the clutch pads. I saw this problem here in a clutch thread somewhere...

MitchP · Jun 7, 2013

Ok. I could SWEAR I saw a pic in a tear-down thread where whoever was pumping red grease into that spot. But yeah she runs.

biknut · Jun 7, 2013

I always fill the transmission shaft area with grease. Even if it does get past the bearing it won't get on the clutch pads.

MitchP · Jun 7, 2013

Yeah I'm pretty sure the noise is coming from the "transmission" shaft. I meant to get a big plastic syringe and pump it in but I figured I'd ask first. It's really thick so I don't think it would become runny. Also I cracked my head in half today (the motor's, not my own) so I put on the old one and it runs the the same.

biknut · Jun 7, 2013

You don't really need to pump 14 gallons of grease into the hole. 13 gallons is plenty, or just do like I do, and stop when you get up to your arm pits.

crassius · Jun 7, 2013

MitchP said:
Ok. I could SWEAR I saw a pic in a tear-down thread where whoever was pumping red grease into that spot. But yeah she runs.

what you probably saw was a reinstall of one that had been out - these usually don't need grease unless you take them out, then put them back in

Huffydavidson · Jun 8, 2013

It was next to the blinker fluid .how the **** do you crack a head in half ?????? terminology it is a clutch shaft not a transmission shaft . it only requires a little bit of Greece just to keep it wet .it doesn't need to swim in the ocean just because you live next to it !!!!!

maniac57 · Jun 8, 2013

Granted, the post mentioned he had been filling it for a long time before it got messy.
I think a little would be good but don't fill it full.

MitchP · Jun 8, 2013

Maniac57,

correct me if I am wrong, "If more is better, then too much is just enough." Obviously I need to buy the Costco size red grease.

Huffydavidson,

I actually bought a torque wrench and set it to 12ft pounds and tightened the bolts in an X pattern. Then while I was riding I just heard 'snap' and then my bike started sounding like a compressed-air tool.

New F80 motor is running rough

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