I was riding the other day and something went out on my motor. I was cruising at about 50 to 60mph. RPMs were coming up so I started to change gears. I think I was probably in 4th going to 5th or 5th to 6th. I was not redlining it...just normal operation.

I switched gears and released the clutch. As the clutch was released something gave way and I hear some bad noises. My initial thought was that the primary chain broke. I get the bike off to the side and immediately shut it off.

After getting the bike home I took the outer primary off and to my dismay I found the chain intact with no other signs that anything broke in the primary (looking at it all together all parts still assembled).

After discovering it wasn't the primary chain, just to rule out the tranny I worked through the gears while it was on the stand. Everything seemed fine.

Then I decided to bump the starter. It fired right up but I immediately shut it off because it was clear there was something wrong. It sounded like the problem was coming from the front/motor.

I drained the oil to see if I would find a bunch of metal. No metal was found in the oil.

Tonight I'm going to pull everything out of the primary to make sure it wasn't the stator that blew up just to completely rule out anything in the primary.

Assuming its something in the motor...oh geez. It's pretty much a freaking brand new crate motor with only 2500 miles on it. And I don't know jack **** about the inside of the v-twin. Guess I have a lot of reading to do.

To clarify, the motor is a 2011 96ci B motor that has been converted to carb. It was a brand new crate motor. No upgrades have been done.

If you have any ideas as to what the problem may be please let me know. It would be awesome to start checking the easy stuff first. Although I built the bike myself, I have never had to get into the motor nor ever messed with any motors.

Attached is a picture of my bike and the crate motor when I got it.

Thx,
D

 

You "don't know anything about vtwins but you're going to take the whole primary apart ". You have "never delt with a motor " of any kind yet you put the crate motor together.
You may just be full of sh@t
If you're not then I say stop lugging the motor around and check the compensator.

 

As I said, I've never had to dig into a motor. My motor was a crate motor...I took it out of the box and hooked it up per the service manual. Yeah, I built the bike from the frame up using a service manual, parts manual, and knowledge I gained from the internet....I've done some hard stuff...but like I said, I've never dug into the motor. I'm a engineer in my day job so I'm mechanically inclined enough to throw some parts together but I've never got into a motor.

Regarding the compensator, I will pull it out tonight while digging for the stator..but I would be surprised if the noise I heard was coming from it.

D

 

I would do two things first. Check compression and pull the cam cover to take a peek inside the cam chest.

 

Will do. I sure hope it is the compensator..that's an easy fix. On a similar subject, if it does turn out to be the comp, what do you guys think about getting rid of it and replacing it with one of those compensator-eliminator gears?

 

I would also try and perform a leak down and compression check. As this is being performs. I would pull push rod clips and rotate engine to TDC and see if there is play in the pushrods. If you dropped a valve. You might be able to see tell tale signs doing this.


OT You avatar looks familiar. Do you mod frames? There was a burnt bike like that sitting at my buddies frame shop for a while.

 

Thanks for the info! This is the kind of stuff that I was looking for..but never done before. With your info below I can start looking for info/guidance.


Nope..never modded a bike frame. This bike is the second bike I've owned, but the first bike ever that I built. My avatar is a picture of my harley before I built it. Basically a house (someone I don't know) burned down around it (it was in the garage)...it was totaled by the insurance company. A motorcycle shop bought it from an auction, stripped it down, re-powder coated the frame, and planned to build it back up. I bought the frame from them when they decided they didn't have the time for the build. I inspected it for warpage/etc, and decided to buy it for a build. I then spent the next 4 or 5 months finding parts for it and piecing it together. I ended up finding the crate motor from a guy in California. I did all the work myself including converting everything from EFI to carb and converting the wiring from CANBUS to 12 volt. I didn't know jack **** about bikes but I did a lot of reading/research and figured things out as I went. It was a fun project. I now have a 1979 Honda CX500 in my garage that I'm converting to a cafe racer/brat.

 

Sounds like you'll be fine, just make sure you get a manual.....

 

I agree with hrdtail78, diagnose before ripping into it. You say it started up after you got it home, that would indicate it has compression. One other thing to do is pull the spark plugs, put the bike in gear and roll the engine over (turning the rear tire).

 

Got home from work and pulled off the comp, clutch, inner primary, and rotor. I did not see any evidence of failure. No metal. No broken or galled gear teeth. The comp had some shiny areas showing evidence of friction/wear, but it was nothing that I wouldn't expect between two parts that rub.

Guess I'll have to start looking at the motor like you guys say.

D