What just happened, one cylinder?

[halfbreed4lyfe]

Ok so she just sort of gave up on me. I'm riding down the street at 50mph, I hear a rattle then my bike dies. I pull over try starting her but nothing, so I hold the throttle and start and it will stay on as long as I'm on the gas,and I keep it above 2K rpms. She will not go more than about 40 and dies if I let the throttle go. Please tell me it isn't something serious, I 'd appreciate that common reply from Bc saying just to clean the carbs. I have a video uploading in a few should be on in about 30min. BTW when it first happened I got a little smoke from the left hand exhaust, and once home I felt that the exhaust on the left was cold on the right was hot. I'm no mechanic, so I dont have a feel for what it could be, I am mechanically inclined enough to fix it however.

 

[drewpy]

any strange noises when you restart?

 

[halfbreed4lyfe]

ok heres the link

. I'd say yes to the strange noise a sort of rattle maybe, metallic. ok now I've put it on the center stand and there is oil leaking from somwhere. Here are pics.

 

[drewpy]

have you checked your valves are operating by removing the cam caps?

compression check would give a good indicator, it sounds like its "gasping" ie no compression!

on mine the engine positively roars into life!

 

[halfbreed4lyfe]

I'm going to try to get ahold of a compression tester tommorrow after finals, and check it out. From what I've read poor compression needs to be followed by a rebuild. Is this true?

 

[drewpy]

depends, low comp with high comp after adding a little oil = worn rings. no change with oil = leaking valves.

 

[halfbreed4lyfe]

Ok haven't gotten a compression test yet, however I removed and cleaned carbs. In the left carb there was oil and a crap load of metal bits. I removed both "valve viewing bolts?" and all looked pretty normal there, went to check spark plug where it appears the oiled leaked at and the spark plug was not even hand tight and its gap was closed and it looked like somthing hit the top of it and closed it. There was a nice gash in the top. ok soooo pics.

to end on an good/bad note all my cool cafe parts start coming in so I guess I can start on that stuff.

 

[bentwrench]

Well... you may want to hold off on hop up parts until you have the engine fixed. They're easier to return if they're still in the box, or resell, if, you know... the worst... this is so sad..... the..... worst has happened...

 

[halfbreed4lyfe]

Yeah I'm going to do some more troubleshooting before I start dismantling my bike. Is is possible that the metal flakes didnt come from inside my engine, I found them in the carbs so would they have been sucked in through the gas line? I dotn have a fuel filter put in. I dont know they were only in one carb.

 

[halfbreed4lyfe]

just did compression test, got 0 in the left cylinder and 30 in the right, gotta go grab some oil and finish the test so update soon.

 

[Jacob]

My completely uneducated guess: Broken cam holding intake valve open and subsequently pumping the metal bits back through the intake valve and into the carb, and causing 0 compression. I don't know where the metal bits came from though. Are these interference motors? If I'm right, all you need is a head with a cam in it...I think...or maybe just a cam...

 

[halfbreed4lyfe]

re-ran compression test put teaspoon of oil in each spark hole this time. Compression stayed zero on left and went from 30 to 70 on the right. So I'm going to check valve clearance properly tom when I figure out how, and pray its that simple for the left. On the right doesn't an increase in pressure show its worn rings? Either way I guess I'm heading towards either a rebuild or new engine. Any input at this point would be much appreciated.

 

[drewpy]

it does, might have a holed piston on the other side!

 

[halfbreed4lyfe]

Blast you Drewpy!!!! No not really but I watched to see if the valves were moving and they were. So I watched inside the spark plug hole to get a glimpse of the piston. Well I see this torn to shit piece of metal moving up and down, and not even a slight whisper of air coming out. It appears I have a holed piston. I did a little research, and I dont like it. So suggestions, I'm willing to remove the head and block and assess damage and try to replace parts however, is it cheaper to simply buy a new motor? Also I read on the 650 site that most who have holed apiston lose the metal chips into the crankcase, requiring a flush or good cleaning of it as well. I've never done this before but after reading the manual on the tear down it seems, achievable. I dont have a fat wallet so I want the cheapest route.
I guess main question do the rebuild or buy a new engine?

 

[dongrady]

metal filings can cause severe damage to bottom end bearings as well. the crank bearings are cheap.

 

[drewpy]

go for it and learn. that's how I did mine.

 

[halfbreed4lyfe]

So I think Im going to go for it then, I want to ask, for a rebuild will I need to be boring, and honing or just really cleaning parts and replacing whats broken.

 

[dongrady]

no way to know till you get inside and measure.

 

[halfbreed4lyfe]

So I should probably invest in a good vernier caliper

 

[Drewcifer]

Re Drewpy's hole piston...yeah, 0 compression does imply a hole in your piston. or your comp tester is done for!

Costwise...
The manual PDF is free, its on the forum front page.

A basic socket set of metric wrenches is also cheap. 15 dollars at harbor freight.

So cheap has always equaled DIY and it will take a while. That's the truth.

1. Drop your oil into a small storage tupperware, the kind with a lid. Mine is sort of like a shoe box size. Throw a magnet into it to catch the filings.

2. Remove stator case and see if anything broke off and is in the stator/rotor assembly

3. Start to take the top end off and check for cam issues, breaks/ chain links busted, wacky stuff. We saw an entire piece fall down into the engine from the cam spindle alignment the other day.

4. Lastly, grab your towel and DON'T Panic. You will find the gremlin, and you will prevail. I've seen motors for sale for 100. I still haven't really looked around at salvage yards for a spare...so I think this is going to get solved. All you need is out there, and you're going to survive. We understand the stress and frustration!

Hang in there.

Drewcifer