B12 off boost running problem

[BanditPervert]

Need help with getting it running, first start Monday and ran on 3 cylinders, carb 3 overflowing

fitted new float valves and seats, set float heights to 15mm, mixture screws 1 3/4 turns out and stock jets.

carbs back on and primed, no leaks. Turned over without plugs and all seems fine, choke on and I get the stumble and popping. Choke off and nothing.

the turbo is only plumbed on the exhaust side.

any suggestions would be greatly appreciated.

thanks 

 

I do have a video but not sure if I can upload on here.

[BanditPervert]

Uploaded vid to the tube 

 

[Askamaskinservice]

Swap connectors TO ignitioncoils if you by accident have switched them.

[BanditPervert]

Already looked at that and I’m pretty sure they’re right

[MeanBean49]

What base fuel pressure are you running? Also worth setting tge floats to 16mm.

Worth trying to run the bike with gravity fed fuel, will show whether its fuel pressure related or a carb issue

[Reinhoud]

What Meanbean says.

Make sure it runs as when stock, then go further step by step.

Don't be pretty sure the coils are right, be sure!

The pressure from the fuel pump should not exceed 2psi.

 

To check if your float needles do their job; connect fuel line on carburfuckingettors, hold carburfuckingettors up side down, blow into line. If you can blow through, the needles aren't doing their job.

Play with floats to see if everything works ok.

 

Float height, is best to adjust by connecting clear tubes on the floatbowls and bend them up. carburetors in riding position, and let fuel run into the floatbowls.

Now you can see  how much fuel there is in your bowl, just adjusting the floats at a certain height isn't that accurate.

Edited February 13, 2021 by Reinhoud

[Reinhoud]

How does it run without plenum?

 

[BanditPervert]

Ok so pulled the valve cover off and timing has jumped a few teeth, manual adjuster wound it’s way back out, probably due to me not tightening the locking nut. 
 

not sure if I’ve bent a valve or there has been any contact. Compression test on cold engine shows around 110 on cylinders 1,3 and 4. Cylinder 2 shows 102. 
 

any ideas what it should be showing cold. And is 8psi indicating a bent valve?

[BanditPervert]

Wet test shows +10 psi on cyls 1,3 and 4 but only + 4psi on cyl 2.

motor has busa pistons and standard rods. 

[clivegto]

Get one of those tiny cameras down no 2 is what I would do for a look see it there are any marks on the piston from the valves or just wipe the head off. 

[BanditPervert]

1 hour ago, clivegto said:

Get one of those tiny cameras down no 2 is what I would do for a look see it there are any marks on the piston from the valves or just wipe the head off. 

I don’t have a tiny camera and this build has stretched the funds further Than I thought they would go!!

I’ll get the head off tomorrow and see what damage has been done. 
 

thanks 

[Reinhoud]

A sort of good way to tell if valves are bend, make something you screw into the sparkplug hole, where you can connect a hose on, the other end to a compressor.

Slightly increase pressure, if a valve is leaking you will deffenitly will hear it.

You'll feel it to on the crank when you try to lock it with a spanner.

 

Don't ask my why I know this sort of dodgy stuff.

[BanditPervert]

Got the head off and all looks to be fine, chambers hold fluid ok and no bubbles.

can’t understand if that compression reading was normal. Gasket is fine and everything was torqued to the APE settings.

 

[MeanBean49]

11 minutes ago, BanditPervert said:

Got the head off and all looks to be fine, chambers hold fluid ok and no bubbles.

can’t understand if that compression reading was normal. Gasket is fine and everything was torqued to the APE settings.

 

Looks to me that you can see on piston 2 where valves have been hitting it

[BanditPervert]

They all look like that, think it’s just the camera lighting. I’m not sure but I think they had that mark when I first got them.

im trying to find the photo.

[BanditPervert]

[no class]

I'm with MeanBean49 on this one....#2 piston shows intake valve marks....does not take much to slightly bend a valve so it no longer seats propperly.

[BanditPervert]

Luckily I have a spare set of inlet valves, (although they don’t have a lovely back cut like these) so will lap those in tomorrow. 
 

Has anyone re used a Cometic head gasket before?

 

[no class]

you can reuse the mls gasket .

[clivegto]

17 hours ago, BanditPervert said:

 

Has anyone re used a Cometic head gasket before?

 

Yes. 

Edited February 15, 2021 by clivegto

[MeanBean49]

18 hours ago, BanditPervert said:

Luckily I have a spare set of inlet valves, (although they don’t have a lovely back cut like these) so will lap those in tomorrow. 
 

Has anyone re used a Cometic head gasket before?

 

What do you mean back cut valves?

[BanditPervert]

1 hour ago, MeanBean49 said:

What do you mean back cut valves?

I had a 30 degree angle put on the valves when I had the seats cut, so I’ve dropped the head off to have the same angle cut and the new ones lapped.

[BanditPervert]

7 hours ago, clivegto said:

Yes. 

Thanks 

[BanditPervert]

Quick update 

the machine shop tested the valves for me and all were fine. Pulled the barrels to see if there was anything in there...

I’ve obviously bent a ring on cyl 2 when installing them. Guess that explains the lower compression reading on that cylinder, so engine is coming out again as I find it a sod to get the barrels back on when in the bike. 
 

Thanks for the help and I’ll be back when I’ve sorted this cluster***k

[clivegto]

Whoops