Almost there (timing?)

[Hartless]

So my bike runs now that I hav it together and everything buuuuutt, it runs bad and idles bad, also spits gas out of the front carb like a mist. Fiatracer and myself concluded that I probably did not get the valve timing right. That is the only thing I can think that would make has most out of the carb. Does this conclusion sem correct?

[QBS]

For sure, double your cam timing.

[Hartless]

i thought i had it right. i mean it is pretty simple. tdc1 for the front, align the cam gear dots with the sleeves.....and repeat for rear but use tdc2....

[Rick G]

You know what thought did, he farted m but shite himself instead!  You are out of time , at least on the front cylinder. Ask me how i know , I did in on the rear cyl. . It was 1 tooth off,

[Hartless]

yea... i was having a problem, i think on the rear though, but i could not get the cam gear spot to be perfectly vertical when lining it up. it was impossible. it was damn close but not perfect....

[Jimustanguitar]

Before I tore mine down, I noticed that one cam on each head was about a half tooth off from aligning with the timing marks.

I was worried that my cam chains were stretched, but it sounds like this isn't terribly uncommon.

[Hartless]

Before I tore mine down, I noticed that one cam on each head was about a half tooth off from aligning with the timing marks.

I was worried that my cam chains were stretched, but it sounds like this isn't terribly uncommon.

That's how mine was exactly

[Jimustanguitar]

I took a handfull of pictures so that I could refer to them for reassembly. It looks like one cam in each head is slightly off.

[Hartless]

Very nice :) I think today I will try and fix it after work, but I'm going to check how far off I was with a screwdriver in the spark plug whole and line the cams up

[Rick G]

Your definatly off, no cigar! try again .

[Hartless]

So I checked the timing..... It is not off. It was right on the money.... Does anyone have any other ideas on what it might be? It still sucks air in but it also pushes air out too

[Rick G]

Hard to tell from the pics but it looks off.,

[Hartless]

Hard to tell from the pics but it looks off.,

Those aren't my pictures! They are not off though I made sure.
Now it's the front carb that is shooting out gas, do I need to check the rear timing too? I don't sw why I would but What do I know

[fret not]

Heartless, did you have your cams out of the heads?

[Hartless]

Heartless, did you have your cams out of the heads?

Well when I rebuilt the motor I did. I don't need to take them out yesterday

[Rikugun]

Heartless, did you have your cams out of the heads?

Well when I rebuilt the motor I did. I don't need to take them out yesterday

So this is the first it's been running since the cams were installed? If so, it seems likely the cams are not timed correctly. It's not unusual for the marks to be off slightly due to chain stretch but this sounds like more than half a tooth off.

As a quick check, turn the motor anti-clockwise to TDC compression (NOT exhaust) stroke on the front cylinder using the "T" mark on the flywheel. Which way are the cam lobes pointed? Now turn the motor another 290 degrees in the same direction to put the rear cylinder at TDC compression. Which way are the lobes facing?  A couple of pics may be helpfull.

[Hartless]

Heartless, did you have your cams out of the heads?

Well when I rebuilt the motor I did. I don't need to take them out yesterday

So this is the first it's been running since the cams were installed? If so, it seems likely the cams are not timed correctly. It's not unusual for the marks to be off slightly due to chain stretch but this sounds like more than half a tooth off.

As a quick check, turn the motor anti-clockwise to TDC compression (NOT exhaust) stroke on the front cylinder using the "T" mark on the flywheel. Which way are the cam lobes pointed? Now turn the motor another 290 degrees in the same direction to put the rear cylinder at TDC compression. Which way are the lobes facing?  A couple of pics may be helpfull.

They are facing outward on the front and at the same time the rear is facing inward

[Rikugun]

Do you mean the rears faced outwards when you turned the motor to TDC for the rear cylinder? If so, would you say the valve timing is correct plus or minus half a sprocket tooth? Are there any mechanical noises that shouldn't be there? Ticking from pistons and valves meeting for instance?

If not, is it running on the rear cylinder? Can you feel heat developing in the rear exhaust soon after starting like in the front header pipes?

How long since those carbs have been on a (good) running motor?

I'm going to check how far off I was with a screwdriver in the spark plug whole and line the cams up

Do you not trust the flywheel marks? Did the screwdriver method and the flywheel marks agree?

[Hartless]

Do you mean the rears faced each other when you turned the motor to TDC for the rear cylinder?

yes

If so, would you say the valve timing is correct plus or minus half a sprocket tooth? Are there any mechanical noises that shouldn't be there? Ticking from pistons and valves meeting for instance?

yes, no everything sounds good

If not, is it running on the rear cylinder? Can you feel heat developing in the rear exhaust soon after starting like in the front header pipes?

yes

How long since those carbs have been on a (good) running motor?

they were on my other motor before it went south, so about six months.

I'm going to check how far off I was with a screwdriver in the spark plug whole and line the cams up

Do you not trust the flywheel marks? Did the screwdriver method and the flywheel marks agree?

yes i do, but with the way it is misting the gas out of the carb and forcing air back out of the carb, i was sure that the cam timing was off and wanted to see if the marks might be a little off.

[Rikugun]

but with the way it is misting the gas out of the carb and forcing air back out of the carb, i was sure that the cam timing was off

I'm unclear as to what's been done to this engine. Are the heads what you've been running or is this a different engine? Is it possible you have some bent valves? Have you performed a compression test or leak down test?

I'm not exactly sure what you mean by "misting the gas out of the carb" or how much but I guess what is important is it's only on one. Are you observing the carbs with no airbox or with the lid and element out? When I've done that I noticed the accel pump stream is no longer a stream when the engine is running but rather looks more like mist inside the air horn. Are both accel pump nozzles functioning? Did you drain the carbs before letting them sit for 6 months?