Bought it cheap, tore it apart, cleaned it up and putting it back together, Was non-running due to case damage when i bought it.
Cleaned the carbs nicely overnight in dip and sonic cleaned it as well for good measure, so i know it's clean. Stock exhaust, new old stock airbox since it came without and i bought a chinese made oem equivalent filter for it (actually compared at the shop, couldn't tell the diference).
Jetting is stock and intake boots on both ends are in good rubber. Only slight problem was a header exhaust bolt that was broken, but it's been sealed with new exhaust gaskets and high temp siliconed for good measure. Getting a nice spark from brand new plugs.
I have stock jets with the idle air mixture screws 3.5 turns out, as well as a shim on the needle. Float height is 14.6mm (I do have doubts about this, since I'd like to try and make it richer here too, and also there's some play on the top plastic part that I don't know if I should take into account) Fuel height was also checked with the tube method and it seems to be pretty close to the gasket surface. All the o-rings are there and in good rubber (viton to be exact). A bench sync was done.
As far as cables and choke go, the choke is off (not something I ever need, I live on a tropical island where the temp ranges from 74f to 87f year round) and the throttle is closed all the way and the idle adjustment is so turned down it's almost off the throttle spring plate.
Only big change is that I don't have a vacuum petcock anymore, since the bike didn't come with one and they're too expensive to buy, so i blocked off the vacuum port on the carb and i ran the reserve and gas ports on the tank to a t-fitting and am running fuel hose with an inline valve (on/off) to the carb.
I've torn the thing apart a bunch of times, played with hose routing. played with a different fuel hose arrangements, I've sealed and siliconed everything I could that would cause a vacuum leak and also I've tested for leaks and none exist.
Big diagnostic things that tells me that it's lean are that when I start the bike the RPMs go way up and that when I cover the air filter port, it comes back to idle. Plugs look normal, some sooting from running rich when I put my hand on the air filter port. Right now my best guess (and that's all it is) is that somehow I'm getting the float height wrong and that's causing fuel flow issues, because a)I had doubts when I was doing it about that play in the arm I mentioned before and b)the bike idles and throttles almost perfectly between the time I shut off flow from my auxiliary tank and it runs out of gas.
Any suggestions or outside opinion? I'm going nuts here and I'm trying to avoid spending since I'm already off budget on this thing.
(Some paragraphing would make your post easier to read)
Have you done anything that would affect the timing? Here at the Bike Cave we had a troublesome bike with the same symptoms: run away throttle but blocking air dropped it down. The timing was off by 1 tooth. We rotated the cams forward one tooth and all was perfect.
Float Height: Use a clear tube and check the fuel level.
Check the idle screw (aka throttle stop). Maybe it is screwed in too far.
Quote from: adidasguy on February 22, 2014, 10:55:09 AM
(Some paragraphing would make your post easier to read)
Have you done anything that would affect the timing? Here at the Bike Cave we had a troublesome bike with the same symptoms: run away throttle but blocking air dropped it down. The timing was off by 1 tooth. We rotated the cams forward one tooth and all was perfect.
Float Height: Use a clear tube and check the fuel level.
Check the idle screw (aka throttle stop). Maybe it is screwed in too far.
Only thing I can think of that I went near for timing was when I removed the signal rotor to put on the new engine cover. The engine rotated while I did that. Would that be enough to cause a timing issue?
Float height seems to be alright with the tube method.
And the throttle stop is so screwed out it's almost off the plate.
It's been a while since my writing's been criticized, believe it or not I'm a writer by trade :icon_mrgreen:
Thanks for taking the time, it's awesome to have people so passionate about a model in one place!
You can verifythe timing rotor. It has marks for TDC. Check the manual for proper alignment.
You can rotate the motor (clockwise only), checking the alignment marks, all the while having a pencil or chop stick in the spark plug hole so you know when the piston is at TDC.
There is a pin on the timing rotor to align it. If the pin gets munched or the slots, the rotor could be off.
Not exactly sure how you have the fuel lines set up without the petcock; could you post pics or a schematic?
For the Idle adjust: after changing jets I found that the best is to set the idle screw so that there is a small gap (maybe .25-.5 mm) between the butterflies and the throttle bodies; this is generally a good starting point and results in a smoother on/off idle stansition than if the butterflies close all the way.
Another consideration is that the stock jetting is somewhat lean; so stepping up the jet sizes may help a bit.
Quote from: adidasguy on February 22, 2014, 11:49:59 AM
You can verifythe timing rotor. It has marks for TDC. Check the manual for proper alignment.
You can rotate the motor (clockwise only), checking the alignment marks, all the while having a pencil or chop stick in the spark plug hole so you know when the piston is at TDC.
There is a pin on the timing rotor to align it. If the pin gets munched or the slots, the rotor could be off.
Out of curiosity, what happens when the motor is rotated counter-clockwise?
Quote from: radodrill on February 22, 2014, 12:47:36 PM
Not exactly sure how you have the fuel lines set up without the petcock; could you post pics or a schematic?
For the Idle adjust: after changing jets I found that the best is to set the idle screw so that there is a small gap (maybe .25-.5 mm) between the butterflies and the throttle bodies; this is generally a good starting point and results in a smoother on/off idle stansition than if the butterflies close all the way.
Another consideration is that the stock jetting is somewhat lean; so stepping up the jet sizes may help a bit.
That is an interesting consideration, because even with the adjuster all the way out there is a small gap there. Is there anyway to adjust that?
Basically its two hoses into a t connection
(http://i.imgur.com/6MBOwMy.jpg?1)
that connects into an inline valve that goes to the carbs (note:connected to an aux tank right now to make it easier to maneuver)
(http://i.imgur.com/EdNwMcx.jpg?1)
Just thought of something; is the tube method for when the bike is off or for when it's running? I've only done it off.
I see so in essence you have just the tank and a shut-off valve; no reserve functionality.
The tube float level check is done with the bike off and petcock in prime (in your case valve open).