Sumthin' broke

[Cowchip500]

Yesterday was the first day this year that we broke 70deg. Of course, I'm riding to/from work. On the way home I start to hear a swishing noise, which I figure is my speedo (which hasn't worked in a year). But after a few min, it gets louder and I can't tell where it's coming from. I think it might be in the primary. THEN, out of now where (I'm doing 45 MPH, flat, straight), it backfires through the carb AND exhaust and runs fine after that for a minute. Then, it does it again a couple times and the swishing noise is getting louder.
I pull over and listen for any knocking noise, there's none. But is sounds like an out-of-round brake drum on a truck and once and a while there's a rattle, like something is loose and rolling around inside.
Of course, I'm in the middle of nowhere, with no cell bars. So I keep going. There's a hill I have to go down, so I pull the clutch and coast. The idle increases & decreases erratically a little.
The noise stays the same if I'm on the throttle or de-accelerating, so I don't think it rod or crank. The back-firing tells me it's possibly the stator but when I pulled it apart, I didn't see anything that looked loose, scored or out of place.
I have no idea what else it could be, other than maybe a rocker arm (maybe). I hate to take the whole engine down to find it. Does anyone have any idea what it might be?
Rob

 

[Cowchip500]

I was watching for the light, cause I don't have a gauge. The oil was clean and full (actually a little over full). It sounds like something rotating.

 

[Vibratinharley]

I had a similar noise on my 90 and it turned out to be drive gear for belt at transmission came loose ( design flaw and has since been updated) It was scraping side of transmission and clanking back and forth on shaft. Might be something to check . And maybe driveability issue is another concern.

 

[glider]

A few things come to mind here. First is a compensator sprocket coming loose but that would give a knocking noise rather than a swishing.

A pushrod tube cocked rubbing on the pushrod. Stock pushrods or adjustable?

Hows the primary chain adjustment? What tensioner do you have?

 

[Cowchip500]

I thought about that but why would the engine run rough?

I forgot to mention that it's a Evo, stock everything. I was hoping it was a pushrod or something in the valve train (other than a valve). That's a good excuse to get a better cam.

It's supposed to be mid 80s here today & I'm absolutely sick that my baby is dead. I had to ride the rice-burner to work instead. :bigsmiley19:

 

[Cowchip500]

While we're at it; what should I be thinking about for a replacement cam? My power curve w/ the stock cam is too short. I need more top & bottom end. If I don't need to replace the lifters, that's a plus.

 

[Fisher]

Fix the problem first.Tell me more about the bike.Mileage,model,mods ya know.


After that's done I've always been happy with the Andrews EV27.Nice all around cam that'll work with stock springs.A good ignition tops it off.

 

[Cowchip500]

I think I may have it solved. A buddy (who turned wrench for HD-Seattle) said that my "timing shoes" in the primary are worn out and probably fell apart. It's a big deal unless I ate up the primary cover. I'm going to pop the cover this morning and I'll let you know.

 

[glider]

"timing shoes" in the primary are worn out.????

He couldn't be referring to cam chain tensioners like in the TC engines that come apart, could he?

They would be in the other side of the engine, not in the primary in any event.

 

[Cowchip500]

I hate to sound so green, but I've never been inside a HD motor before. I've built lots of SB & BB Chevys and several other engines, so I think I can figure it out.
The other night I went down to "Thunder Thurs" at the local road house. There must have been 400+ bikes and only 1 guy that had a clue about the inside of an engine. I was kinda surprised that 90% of the "bikers" don't even change their own oil.
Anyway, he told me to pull the primary cover and it would be obvious. I have a new inner chrome cover, so the outer has to come off anyway.