Almost there (timing?)

[Rick G]

Its very frustrating for me ! I'd  love to jump in the truck and  drive over  to your house and look at it!

[Hartless]

I put a new crank and rods in my engine. Yes I drained the carbs but I'm going to clean them again. It is not squirting a stream of has straight up,just a mist constantly flowing straight out of horn enough to hit me in the eye while I was standing next to it. Heads were good last time I used them.

Though I might have separated the head and cylinder when putting it back on, if it has a bad head gasket could that be the cause?

Its very frustrating for me ! I'd  love to jump in the truck and  drive over  to your house and look at it!

Well shoot on over! It sure as h ee double hockey stick is frustrating me!

[Rikugun]

Is it gas or coolant misting from the carbs?  :P

I would think breaking the gasket seal between cyinder and head may be bad.  :(

[fret not]

Heartless, if you put your hand over the carb does it suck or does it blow?  Or does it do both?  Accelerator nozzles are functioning properly and pointed down the throat of the carbs?

When the cams were out did they get mixed up EXH for INT etc.?

[Lucky]

I would think that with the valve covers off and a socket on the crank you could slowly turn each cyl over on compression stroke (@ TDC) and verify that all the valves are opening & closing at the proper time.  Close observation may reveal the cause...


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[Rikugun]

I thought that was Adam was doing but this statement has me thinking something is still very wrong...

just a mist constantly flowing straight out of horn enough to hit me in the eye while I was standing next to it.

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

When I questoned this you corrected yourself but I want to be sure you are clear the two pistons are not at TDC at the same time. After doing the front the crank has to be repositioned to align the rear cylinder cams.  I would quadruple check the timing - as Fret pointed out it is easy to mix up the cam sprockets orientation. Also, is it possible valves were bent after an initial incorrect timing when the starter was used?

[Hartless]

When I put my hand over the carb it sucks and blows.
I was clear that they are not both at tdc at the same time, and have been following my book when setting the cam timing. The timing was set correctly initially so I don't think it would bend the valves.  If I get a chance this week I am going to pop the carbs off and I'll be able to check the valves a little easier and such.

And I did take the covers off and rotate it by hand. It's when I started it afterwards to try and figure it out again that it shot has in my eye

[Rikugun]

When I put my hand over the carb it sucks and blows

It's supposed to - suck, squeeze, bang, blow.  ;D Which carb is doing the misting, sucking and blowin'?  ???  8)  Or is it both? Did you ever do a compression test? And did you say both cylinders exhaust get equally hot more or less simultaneously?

Are you sure this isn't just carb issues? With Visions, 86 and one third percent of the time it's carbs. :P  If you think it's electrical - it's carbs. If you think it's carbs - you're right. But the problem is much worse than you first thought. Once in a while it's the starter or stator but then it's right back to carbs.  :)  :D

[Hartless]

When I put my hand over the carb it sucks and blows

It's supposed to - suck, squeeze, bang, blow.  ;D Which carb is doing the misting, sucking and blowin'?  ???  8)  Or is it both? Did you ever do a compression test? And did you say both cylinders exhaust get equally hot more or less simultaneously?

Are you sure this isn't just carb issues? With Visions, 86 and one third percent of the time it's carbs. :P  If you think it's electrical - it's carbs. If you think it's carbs - you're right. But the problem is much worse than you first thought. Once in a while it's the starter or stator but then it's right back to carbs.  :)  :D

It's the front carb, and I have the exhaust loosely on hat in case I have to take the engine from the frame again. The bike is running on both cylinders and I haven't really run it
Long enough to be able to tell If ones hotter than the other.

[Hartless]

Checked all the valves and they are moving freely, but I think I will check the clearances tomorrow.... The frot cylinder isn't even getting hot. I took the pipes off and there is barely any exaust coming out leading me to believe that the intake valves aren't opening and/or closing enough

[Jimustanguitar]

The cam timing procedure does have you spin the engine ccw, you caught that it wasn't clockwise, right?

I'm sure you did, but I know that's a mistake that I would make :)

[Hartless]

Yea. I tried all ways haha

[Rikugun]

Checked all the valves and they are moving freely, but I think I will check the clearances tomorrow.... The frot cylinder isn't even getting hot. I took the pipes off and there is barely any exaust coming out leading me to believe that the intake valves aren't opening and/or closing enough

Why would the valves not open? Aren't these the heads you were using before? Did you change shims when you swapped cranks? Did you crank the motor over when the cam timing was wrong?

Earlier you stated both cylinders were running now it seems the front isn't getting hot. I'm now feeling Rick's frustration.  :(

Start with the basics. Finish assembling the bike including the exhaust. Check your valve clearance. Ensure both cylinders have spark. Beg borrow or steal a compression gage and use it. Clean the carbs and try again to start it.

[Jimustanguitar]

My thoughts are starting to lean towards no compression due to an open valve. Perhaps one of them doesn't have any clearance and is being held open by the heel of the cam. If you cut new valve seats or lapped them a lot, you'd definitely need thinner shims.

Like everybody else is saying, check your compression and measure your clearances. I think that will tell the tale.

[Hartless]

My thoughts are starting to lean towards no compression due to an open valve. Perhaps one of them doesn't have any clearance and is being held open by the heel of the cam. If you cut new valve seats or lapped them a lot, you'd definitely need thinner shims.

Like everybody else is saying, check your compression and measure your clearances. I think that will tell the tale.

This is what I am thinking as well. I have started with the basics, then put it back together as repeat. The only thing I have my done is use an actual compression checker and check valve clearances. The valve caps fell off and I'm guessing I did not put them back on correctly, that I did but apparently not. By hand it feels like its getting compression, but not enough and at least one of the valves is staying open and air is pushing back out the intake

No need to get frustrated! I should be the one frustrated!!!!

[VisionMeister]

You stated that the rear cams face inwards.
According to the manual, the rear cam lobes should face outward, away from each other. The fronts should face inward towards each other.

I have mis-timed my Vision before resulting in one cylinder blowing out the carb.
My mistake was that I was too focused on aligning the punch mark on the cam (not the gear) without realizing that the cams have two punch marks each, one for installation in the front cylinder and one for installation in the rear.

If you make sure the cam lobes are facing the right direction and the punch mark on the gears are  alligned the punch marks on the cam will fall into alignment.

If all is aligned and you are still getting blowback you must have a partially open valve that is either sticking, not shimmed properly, or not seated.

[Hartless]

You stated that the rear cams face inwards.
According to the manual, the rear cam lobes should face outward, away from each other. The fronts should face inward towards each other.

I have mis-timed my Vision before resulting in one cylinder blowing out the carb.
My mistake was that I was too focused on aligning the punch mark on the cam (not the gear) without realizing that the cams have two punch marks each, one for installation in the front cylinder and one for installation in the rear.

If you make sure the cam lobes are facing the right direction and the punch mark on the gears are  alligned the punch marks on the cam will fall into alignment.

If all is aligned and you are still getting blowback you must have a partially open valve that is either sticking, not shimmed properly, or not seated.

What I meant was when I had the front cylinder at tdc the rear cylinder lobes faced inward. I'm double and triple checking again after work today

[Rikugun]

You stated that the rear cams face inwards.
According to the manual, the rear cam lobes should face outward, away from each other. The fronts should face inward towards each other.

OOOPS! There ya go, we had it backwards. That's probably it afterall. Nice catch Vision Meister.  :)

[Hartless]

So when the front cylinder is at tdc, the rears should be facing inwards? My haynes does not even reference where the cams should be for the rear when the front is at tdc. I just figure since they rotate opposite the lobes would be opposite.. Am I wrong?

[VisionMeister]

approximately so.

Check wikipedia for Yamaha Vision.
Humber, in Europe, has been so kind as to load pdf files of all available yamaha service manuals.
These are easy to download and store in my documents and don't take much memory.

This is where I had my timing problems. I had an old harcopy manual that had missing pages (misprint) right at the cam timing section. I did this on two separate Visions I was working on at the same time, so I got a lot of practice.