Almost at the finish line.. then mega trouble. please help

[Mitchell_p]

Hey guys. I am almost at the finish line of building my little chopper.
I bought this motor from a guy in Brisbane without seeing it. Was told it was rebuilt not to long ago. Was clearly not as soon as it turned up at my door. It kicked over so i thought i would cross my fingers and go ahead to try and finish it by summer in Australia. Which starts this wednesday i think.

Anyway i kicked it over tonight for the first time and the right cylinder i believe is not running properly. Now im not sure, would the bike idle If either the exhaust valve or intake valve was stuck? I had it idling, But their was an awful squealing (for lack of a better word ) noise coming from the right side.Its not a constant squeal, it sort of goes intime with the piston. I noticed that the pressure coming from pipes was alot less on the right side( no mufflers at the moment ). Also the right side was alot cooler than the left when i put the bike away. It almost sounds like a pet squeak toy is in the motor. I have a video of it on my phone that i am going to youtube it later. Ill add the link to this tomorrow if i can. You can hear it so clearly in the video.

Heres the link to my bike running video.

 

[Dusty]

Time for a comp. test. I had a frathead with a blown head gasket do the same thing.

 

[daroberts3]

Sounds like it is running on one cylinder (left side only). What is the status of the carbs? Could be something as easy as a plugged fuel passage

 

[Mitchell_p]

Yeah compression test sounds like the way to go. just gotta get my hands on a compression kit. Thanks guys.

 

[CDNTX650]

are the carbs synced?

 

[Mitchell_p]

Carbs arent synced. Ive rebuilt them but thats all so far. Gotta look into getting the tool to sync them.

 

[XSLeo]

Sync tool cost about $5. Easy to build. Find it in the tool thread in the TECH section.
Leo

 

[Tim of DO THE TON]

Valves adjusted, timing set? Do the 'mechanical' things first, make sure you have fresh properly gapped plugs, and then sort the carbs out.

But yeah, a compression test is a critical first step. Leak-down would be even better to pin-point any loss of compression, but a simple compression test will tell a lot of the story.

 

[CDNTX650]

id say thats backwards.....Sync after all the stuff like valve lash check etc. Usually if it's not running right on one side it's a sync issue. Unless comression is that bad on that side. without a good sync you could chase something thats not there.

 

[hotdog]

MitchelP, nice bike - more pics please.
As suggested, set the valve clearances & compression, sync the carbs & check the ignition timing is good. What ignition are you running..?? a bad condensor (if points) will make it run like shit. The squealing sound doesnt sound good - if the clutch cover has been off for an extended period of time by the PO it might have shit the RH main bearing...??? Anyway do the simple checks first & post your vid, let me know how you go getting the chopper on the road, curious to know of what loopholes you may be exploiting or if its fully engineered..??

 

[Mitchell_p]

Hey hot dog. Thanks for the tips. Ill hopefully get some photos on when i am finished. I feel like a phony if i post photos and it's not even running proper. As for the engineers cert and all that. To be honest i don't know how i am going to get around it. My best plan so far was to take it to a shit mechanic to get the blue slip and offer him $50 ontop or something. Also its just a points ignition with a new condensor but old points. Ill have to take a second look at it all now that the shit has hit the fan.

Also here is the video of my bike "running".
This is the first time it kicked over and i sort of scrambled for the camera so its abit shakey, sorry.

 

[inmotionphotog]

G'day Mitchell.

Your bike is looking really sweet, congrats.

We'll have to go for a cruise once you've got your sorted and mine completed.

Cheers

Steve

http://inmotionphotogxs650.blogspot.com/

 

[I am Carbon]

sounds like an exhaust leak to me like a blown head gasket

 

[Tomterrific]

You may be able to pin point the squeal by holding a length of hose to your ear and holding the open end close to where the noise is coming from. The sound will be distinctly louder when the hose is pointed at it.

Points ignition is my prefered ignition because of how simple, rugged and industructable it is. Most people seem to believe ignition is magic but once figured out it is very easy to deal with.

The idle jet on one carb may be plugged leading to idleing on one cylinder but the cylinder fires when the throttle is opened. This is such a common problem that I don't even think about the symptoms too much but just post an easy fix to try.

Pull out the mixture screw from the carb. Stick teh little tube of spray carb cleaner inside the hole. Blast teh plugging dirt back to the float bowl. It seems like the plug may be hard varnish in your case, so let the cleaner work a bit and blast again. This 'quick fix' may save you from tearing into a carb and save much time.

Tom Graham

 

[blackbetty]

Dude that chop is fuckin sick, post more pics.

What front end is that?

 

[hotdog]

I've found a loophole - for my situation anyways. In QLD if you live more than 50kms from the nearest Safety Inspection centre - you just have to take it to the local Police station & complete a statutory declaration to state the motorcycle is in road-worthy condition etc...

 

[Mitchell_p]

Thanks for all the tips guys. I will try pretty much everything before getting into the valves. Ill set everything starting with my cam chain etc. Go into the carbs abit. See how we go from there. Ill post more pictures soon if you can wait. The front end i was told was off an early Xs, it came with these 4" extension that screw into the top. I never seen anything like it. Pops tue front up just that bit extra to give it a slight chopper style stance. Ill post close ups later.

 

[80xs650]

That sounds a lot like a bad vacuum leak. I had one that annoyed the hell out of me for a long time. It would come and go. I replaced the throttle shaft seals a couple of times because the leak seemed to be coming from there, but it wasn't. It turned out to be the enrichener body (they call it the starter body on the parts diagrams) gasket on the right carb. I tightened it up, which made it better, then replaced the gasket and it went away.

Get a can of carb cleaner with the spray straw on it, and with the engine idling, lightly spray a little at a time around the enrichener body, throttle shaft ends, carb to carb holder joint, carb holder to head joint, and any other areas where air may leak in on the intake side. If there is a leak, you should notice the engine speed change up or down. If it does, then you have found your leak, and tighten/seal/replace whatever is causing it.

I hope this is your problem, as it is usually a cheap fix. Good luck. Nice bike, BTW.

 

[Mitchell_p]

Thanks 80Xs i will give that a shot. I started it last night to see if i could hear where the sound was coming from and it was not running for more than 10 seconds when it backfired and blew the carbs out of their holders. This would possibly mean i have my points wires backwards? Or just that the timing is off. Anyway i took that as my chance to clean the carbs again while theyre off and possibly fix any leaks. See how we go then.

 

[XSLeo]

You say that you never saw anything like those 4 inch extensions. There is a good reason for that. They kill people.
The fork tubes break at the joint where the extensions screw in. This lets the forks flex in unexpected and uncontrolable directions.
I would remove them and if you want longer forks replace the tubes with 4 inch longer tubes.
Leo