[LouG]

This is sounding like random noise syndrome. It's common when riding a long way from any help.

 

[Steve H]

I'm with everyone else its cranking fine...dont forget this is a crossplane triple...for the possible performance issue....run some fuel system cleaner through.

good luck

 

[quickstang87]

Here's a quick update: I seafoamed the engine and blew lots of smoke everywhere, lol. The engine didn't run any better. I then tried to sync the throttle bodies and I have an issue. The first and 3rd cylinders pull massive vacuum according to my home made tool, but the 2nd cylinder won't even come close to pulling the same vacuum. The vacuum adjustment on the 2nd cylinder was turned all the way clockwise until it wouldn't go in any further. I tried adjusting it back the other way but no matter what I do, I can't get the cylinders to balance out. It's not even in the ballpark.

The next step is a compression and leak down test. I will give another update tomorrow!

 

[Steve H]

Some reckon seafoam is little better than nothing. The middle cyclinder not pulling vacuum may be due to it not firing properly....perhaps the plug or coil pack need attention. What about swapping components over to see if the problem, (lack of vacuum) moves?

 

[peabrain]

i would add to check for vacuum leaks and check to see if the throttle bodies are seated properly even perhaps take the throttle bodies of including the boots to check em all

 

[quickstang87]

Well the results of the compression test are in:

Cylinder 1: 180 psi
Cylinder 3: 170 psi
Cylinder 2: 30 psi - I tested this cylinder twice, just to make sure the reading was correct.

No offence to anyone posting in this thread, but there hasn't been a lot of help on this one. Obviously this is an issue that doesn't happen very often, but every single person who posted after watching both of my videos claimed that my bike "sounded fine" when I insisted that something mechanical was wrong.

I will reiterate what I stated earlier. If your bike truly sounds like mine does when you start it up, and it seems to lack power at low RPM, maybe a compression check is a wise idea.

When I get back from work this afternoon I will hook up the leak down tester and verify where the compression loss is going.

 

[quickstang87]

100% confirmed: I have a bad exhaust valve on #2 cylinder. The leak down tester worked perfect and verified my fear. I could plain as day hear the air coming out of the exhaust.

The next step is to pull the motor out. I know I can probably pull the head without pulling the motor, but I need to fix an issue with it popping out of 2nd gear.

Any recommendations on a head rebuilder?

 

[Steve H]

Both a leak down and compression test were suggested early on..but yes you are correct in thinking most wouldnt suspect a burned or damaged valve on a bike with such low mileage. I guess the lack of power was only somethiing you could experience first hand. Good luck with it.

I would pull the head and check the valve...you may get away with a new valve and a simple lapping job...or take it to a competent engineering company who can advise you.

I wouldnt take it to a Yamaha dealer. Worse case scenario would be a burned valve seat which may entaile a new head...not really looked into whether the head has seat inserts or not...given the budget for these bikes I would suggest not.

 

[OldSchlPunk]

I would guess all the valves have seats, especially the exhausts. Aluminum would never hold up to that kind of abuse.

 

[LouG]

You were told to do a comp test. Trying to diagnose a problem via the internet is never accurate, your bike sounded fine on the clip.
You had plenty of help, the ingratitude isn't conducive to getting more.

 

[LouG]

Both a leak down and compression test were suggested early on..but yes you are correct in thinking most wouldnt suspect a burned or damaged valve on a bike with such low mileage. I guess the lack of power was only somethiing you could experience first hand. Good luck with it.

I would pull the head and check the valve...you may get away with a new valve and a simple lapping job...or take it to a competent engineering company who can advise you.

I wouldnt take it to a Yamaha dealer. Worse case scenario would be a burned valve seat which may entaile a new head...not really looked into whether the head has seat inserts or not...given the budget for these bikes I would suggest not.

You have to have seat inserts on aluminium heads. They may be cast into the head.

 

[RichBinAZ]

You may get lucky with the valve seat an it may work by just lapping in a new valve. Damage to the seat will need a new seat, if cutting of the damaged seat doesn't work - and I don't know where to take it to in town to get that done right. You may get some leads thru old car restoration companies or car engine shops. Some of the old timer non-dealer bike shops might be helpful.

The popping out of 2nd is going to be a pain too. There was a thread on here a while ago about a transmission making clicking noises which took a long time to find... anyway, that means the motor coming out and splitting the cases to look at the dogs and windows that give you second gear, see if they have been rounded off with too much harsh shifting, missed shifts into second etc. That thread is worth searching for. Lots of handy pictures and videos

 

[quickstang87]

I found a cylinder head shop up here in Glendale that is willing to take a look at the head and hopefully fix it. I have the engine ready to remove and plan on getting it out of the frame tonight. Once it is out, I will yank the head and send it to him. I have a regular engine stand so I need to make some adapters to bolt the FZ engine up so it can be rotated around and worked on in the air.

From what I understand, to fix the transmission, the engine will have to be disassembled, but the cases will not have to be split. That should be a lot easier.

I will update as I make progress!

 

[quickstang87]

I got the head off tonight and what I found is interesting. One exhaust valve on #2 cylinder is burned so bad you can see daylight through the edge where the seat is. Its hard to tell if the seat is damaged, and I probably won't know more until the head shop takes it apart. I know I need at least 1 exhaust valve.

If I can get the pics to upload I will post some!

 

[LouG]

Did you check clearances before pulling the head off? It'll pay to ask the experts to give an opinion on why it burnt.

 

[quickstang87]

I did a valve adjustment when I first bought the bike, about 150 miles ago. The exhaust valves were way out of spec. There was a gap, however, but maybe it wasn't enough and caused 1 valve to burn.

Uploading pics on this site is a pain, lol.

 

[Steve H]

Would be interested to see this...

 

[quickstang87]

Still getting nowhere posting pics, lol.

I took the head to a shop today and the machinist pulled out the bad valve. The valve of course is toast but the seat looks ok. He said I might be able to get away with just replacing the valve, cleaning and checking/surfacing the head. He didn't have tools small enough to cut the valves and the seats, but I don't think I need to do that if a new valve will seal in that old seat.

Any thoughts?

 

[quickstang87]

I said "F" it and just made another video, lol.

 

[Steve H]

That seat looks OK...although its difficult to see fully from a vid. The valve looks horrendous.....maybe it was a faulty valve tip only...fingers crossed....appologies for doubting you lol!

good luck