She's now running, but somethings not right ?

[dusty350]

Hi
Finally got the F2/Tzr hybrid out of the garage today, and fired her up for the first time. Took a few kicks but I sort of expected that. Anyway, engine sounded sweet, but I found water dripping down the front of the left barrel. At first I thought it was the head gasket, but soon found it was the temp sender in the middle of the head. It is the Koso item I fitted the other day, so I removed that and fitted the original Yam one I had new from Norbo, so that problem was solved. Will sort the Koso out at a later date.
So, using the auxiliary tank with premix at 25:1 the bike ticks over nicely, but as time went on I felt the right cylinder was pulling the left along with it. The right sounds as it should whereas the left feels flat like it's gonna run out of fuel. The left side doesn't get as hot as the right either, and smokes a lot more out of the pipe, plus the exhaust pulse isn't as strong out of the left side- almost like it's not firing properly. I got through 2 litres of premix today, and it never sounded like it was conk out, but a bit flat, especially after it had been running for a time. Last thing I noticed was the carb on the left felt cold, and the left side of the metal balance tube started to form condensation If I rev the bike it picks up well, but pumps loads of smoke out the left pipe. Tail pipe is cooler on the left, but both cylinders feel hot to the touch. I will see if I can upload the vid I took, but in the meantime, any ideas guys ?

Dusty

[muddyfox]

id check float level, are you using clear petrol hoses, mine was the same and found the float level on the carbs was wrong and tank breather was the problem as well, the tubes had large air pockets and not getting fuel

whats your air screw set to? maybe it may need adjusting, check timing?
you could pull that exhaust and check for fuel in there?

[dusty350]

Hi
Timing is standard F2. May need to look at float heights. Carbs have been through my Ultrasonic cleaner and are 31k non pv. 290 main jets as a starting point for the Tsa pipes and pod filters. New rebore and crank, all gaskets are Yam genuine. Video is uploading so I'll post it in a mo.

Cheers

Dusty

[muddyfox]

same carbs as mine, i also found the the pipe between the carbs was old and stretched, replace out of precaution,
my main is 240 and its still a bit fat with allspeeds, whats the rest of the jets?
22 or 27.5 idle
5 something needle, clip 2nd from bottom, i jet mine for clip in the middle
air screw 1.25 mine is at 1 turn out

what plugs dude? going up heat range can help with icing carbs

[dusty350]

Hi,
All petrol pipes are new black pipe from Norbo
I haven't changed the pilots so they are standard,
Plugs are new Ngk BR8ES,
I had exactly the same set up on my Lc hybrid except pipes were Allspeeds, and that ran perfectly. It seems the right cylinder is fine but the left is not so. And Photobucket is hiding my uploaded video somewhere I cant find it

Dusty

[oldelsieboy]

Does it make any difference if you activate the choke?

OEB

[arrow]

Hi Dusty, interesting about the cold carb. This would normally be caused by increased air velocity on that side, generally caused by the engine sucking through a smaller opening. Check the slide heights and idle screws against the other side.

[dusty350]

Hi Nigel,
Not really, I did try that. I was gonna swap the plug caps over to see if the problem changed sides but I've run out of daylight now, plus I've got a short fuse when it comes to things like this so I decided to put her back in the garage for now. Still trying to upload the vid but Photobucket tells me it's uploaded to the F2/Tzr album but it's not there, or in any of the other albums

Dusty

[dusty350]

Hi Arrow,
I will have the carbs off tomorrow and check everything. Thanks for the heads up. Thank goodness I didn't have an airbox fitted, the carbs were a really tight fit/pita to work on !

Dusty

[dusty350]

Hi Headcoats,
Cant ride it yet. At first I thought the extra smoke on the left side was from the rebuild and the bike is on it's side stand, but it's run long enough to burn any excess off. It's just not firing properly or burning the mixture properly on the left.

Dusty

[arrow]

You could try swapping the sparkplugs over but the cold carb sort of rules that out.

[dusty350]

Right, I have finally uploaded the video to Youtube, as Photbucket and Flikr both had problems wit it. Excuse the camera work, whilst I was doing the vid the gearchange lever came loose and was rattling around and I couldn't work out what the noise was at first
I was also running out of fuel so it sounds particularly lethargic at the end, but you will see what I mean about the smoke on the left side;



Dusty

[midlifecrisisrd]

To me the cold car would be from too high fuel flow so would checknow float height and whether needle valve is closing properly.

Rich mixture would cause the smoke just like it does when you leave the choke on

Steve

[dusty350]

This is the other vid;



Dusty

[yamark]

That does look a bit weird Dusty. With Steve on this one, looks like over fueling, but it's also not burning cleanly.
Think about it tonight, you will get to the bottom of it quickly.

Just thinking out loud - Check to see if your coolant level isn't going down, possibly water diluting the mixture? smoke does look quite white.
Keep us posted on any new info.

Chin up and have a beer 

[steve h]

Exhaust cooler on the cold carb side as well? Run it for a short time. Put B8ES plugs in if you have resistive caps, and I would try switching plug leads over. Sounds like its just not firing and burning mixture on the problem side hence the cold cyl and carb. Hope its something simple. Got another coil to try? could be just the left lead.

Ps somehow got it in my head that you've got the separate coils fitted, the banshee ones.

[Delbert]

Reminds me of an early 250 I had that had the carb slides in the wrong way round

[muddyfox]

have you not pulled exhuast yet! your asking for trouble, if its chucking fuel it might get fuel locked and that will be bad, how do i know, also RG owner!
my money is float hieght!
does the tap shut off good? other side is happy!

[gringo]

Dusty,excellent build as usual ,stick it in the garage overnight mate,sleep on it and and you will get to the bottom of it tommorow
Gringo

[arrow]

Dec 17, 2014 22:45:52 GMT 1 gringo said:

Dusty,excellent build as usual ,stick it in the garage overnight mate,sleep on it and and you will get to the bottom of it tommorow
Gringo

+1, another stunning build Dusty.

[steve h]

Dec 17, 2014 22:45:52 GMT 1 gringo said:

Dusty,excellent build as usual ,stick it in the garage overnight mate,sleep on it and and you will get to the bottom of it tommorow
Gringo

If you sleep on it you will get piles ON your bottom. They are much too hard, use a mattress.

[JonW]

Looks bizarre and defo not right. Smoke looks blue to me, maybe its my screen? but I would say its not water, its too much fuel. I agree its not tuned right and defo sounds like it sucks air as you rev it and looks like the choke is on on the LH cyl but not the right. After doing the coil / plug tests I would look to pulling and going through both carbs to check the slides and then prove they both receive and switch off the fuel flow with the float properly. HTH.

[dusty350]

Hi all,
Thanks for the replies so far. Fairly demoralised last night I have taken ages building this with lots of new Yam parts. Done a few in the past and never had issues so this was a surprise. I stuck it back in the garage and took my lad kick boxing where he kicks the ar*e of blokes twice his age, so I felt better when I got home!!
First thing I'm gonna do today is drain the water - I have a drain point on the NK water pump cover, so I should get out what I put in. I have a feeling it's drawing coolant into the cylinder. Brand new Yam head gasket was used and the head was a good unmarked one off ebay. I will also pull the left exhaust and see what's in there.
Air screws are set as per the haynes manual. The slides are synced with each other - easy to check with no airbox fitted. Pilots are standard 31k, 290 mains to compensate for the Tsa's, pod filters and premix.
All gaskets on the inlet side are brand new Yam, and I've used them both sides of the reed spacers. I don't think I've got an inlet air leak. Carb rubbers are good with no crazing, and cross over tube is a really tight fit. I was very careful building the engine so if it is the head gasket, I will be surprised as never had a new one fail. Head bolts are torqued properly and are new stainless items.
Thanks for the help guys, and Yamark for the pm, I really appreciate it. I will update a bit later.

Regards

Dusty

[dusty350]

Forgot to add, I have only used the auxiliary tank to supply the premix, and I let the carbs run dry to kill the engine as I did consider hydraulic lock.

Dusty

[midlifecrisisrd]

Have you upped the pilots

Also before taking the head off undo the base bolts then re torque the head and re tighten the base bolts

Steve

[reggieperrin]

Hey Dusty,

I know that everyone has been throwing ideas at you and most of the bases have been covered.
Here's a wacky idea, but it's just a thought...
The LH cylinder and exhaust does have all the traits of the carb slide being fitted the wrong way around, lethargic revving, slow to pick up, excessive smoke etc.
Is there any chance that the slide is the wrong one? were the carbs built from parts? Bought from the bay?
It's just a thought and I don't think you'd assemble them that way but stranger things have happened late at night in a garage when we're tired...!

Although, the condensation on the balance pipe is a pointer to something else....
good luck hunting it down...!

[dusty350]

Hi,
Thanks for the pointers fellas. The carbs were complete, from Littlebloke on this forum. I have just drained the Procool from the drain point on the impellor cover. Bearing in mind I have one of Norbo's large rads on this bike, and the system was dry to start with, I added over the standard 1.5 litres. Today I drained less than 800ml, and that's with turning the engine over a few times, and leaning the bike to the right side so I reckon it's burnt about 900ml of Procool which would explain the smoke. Gearbox oil is clean, so no leaks there and no external leaks anywhere either. I removed the left exhaust and there was approx. half a cupful of black oily water/ petrol in it. Will remove the right pipe in a mo and then put them back on. I may run the bike up briefly without coolant to see how she runs - not long enough to get hot, and see if that sorts it. Looks like another headgasket then
Update soon

Dusty

[dusty350]

Right side pipe was clean, with no fluid in it. I ran the bike for a few minutes without coolant, and it definitely runs more like it should, not boggy on the throttle like yesterday, and both cylinders sound equal. Still more smoke on the left side, but I don't know how much coolant is left in the engine to burn off. I will post a latest vid up in a mo.

Cheers

Dusty

[dusty350]

This is the latest vid. Only diffence now is that is running with no coolant in the system;



I only ran it for a couple of mins - didn't want it getting hot !
I will order a new head gasket and fit that and then once I've run it I will look at carbs.

Dusty

[dusty350]

Hi
Head is off now and I cant see any reason for the leak. I drained about another 100ml of coolant out but that's all. Gasket looks fine - it is a new genuine Yamaha gasket, but I've ordered a new one anyway. I've placed the head on a flat piece of glass and don't think it's warped - I cant get it to rock at all. Everything else in the top end is new and looks fine so I'm a bit stumped
I will rebuild it with the new gasket and add fresh coolant and try again. If it still leaks I would assume the head is at fault as I've never had a bad Yam gasket, let alone 2.

Dusty