Trust me, I’m not thrilled either, but I’ll get it handled.
Look on the bright side, least I found an injector upgrade you didn’t know about. #ItsTheLittleThings
Gen 2 turbo problems
- Thread starter busakiller
- Start date
Look on the bright side, least I found an injector upgrade you didn’t know about. #ItsTheLittleThings
Absolutely.
I have many theories on this.
The guy that sold him the bike said he put a thicker head gasket in, along with studs and valve springs. I find it odd someone would pull the head to do that to lower the compression, but not put stainless valves in too. Let’s say the previous owner did put valves in. “Drop in” valves still need to be at a minimum lapped in order for them to seat correctly and seal. If the guy didn’t do that, that’s where we could be losing compression. Typically when intake valves aren’t sealing there’s usually a fair amount of carbon buildup on the intake runners from combustion gasses pushing past the valve seats. His are pretty clean. So probably not it.
As far as I know, a thicker head gasket doesn’t exist for Hayabusas as you can use base spacers. This bike has a stock base gasket in it. But I can for sure tell the head gasket is aftermarket, and the head has been off the engine. But the engine has not been removed. This tells me it does not heave head studs of any kind as you cannot pull or install a head with the engine in the frame when it has studs of some sort. So that means factory head bolts were probably reused, and those never torque right.
On a known healthy .080 base spacer motor, you’ll usually see 140-150psi on a compression test. IF this bike actually does have some sort of thicker head gasket on it, it would have to be about .080 thick to get those readings. It looks like a standard MLS Cometic gasket. My guess is the previous owner had the boost too high on the stock motor and pushed the head gasket. If you push a head gasket bad enough it can damage the mating surfaces and you won’t get a proper seal unles the block and head are machined flat again. That might explain the one real low reading, but not low across the board.
So that leaves us with pistons/rings. We know from the first dyno sheet he posted that it was tuned in the mid 12 afr range with fluctuating boost levels. The plugs I pulled out have 10 miles on them, and they have obvious signs of detonation. The factory rings are really thin, and expand rapidly if the tune isn’t spot on. I wouldn’t be surprised if we find some cracks in the piston ring landings, and some obvious melting on number 3 based off of how much aluminum is on that plug.
I already have the oil and coolant draining. I’m going to pull the motor in the morning when I get off work. We’ll know something in the morning.
ali123
Banned
Im glad this is gonna get sorted out.. but on a side note I cant give boosted shyt anymore for not having any org customers
ali123
Banned
maybe some top end work/turbo pistons..... so u can crank up the boost a lil?Im glad this is gonna get sorted out.. but on a side note I cant give boosted shyt anymore for not having any org customers
busakiller
Registered
Waiting to see what the inside of the motor looks like. Before we decide on how deep he have to go. Was really hoping it was a easy fix and a good tune.
ali123
Banned
motor is coming out..... just add a grand to whatever u had planned on spending...….... welcome to turbo country.... but itll last forever after this.
Im glad this is gonna get sorted out.. but on a side note I cant give boosted shyt anymore for not having any org customers
Several of my customers are on here. They read, but never post.
A grand doesn’t even cover the cost of the pistons and rods. $1300. Then cylinder resizing, bearings, main studs, and labor.
ali123
Banned
ure rebuilding the whole motor?
john blaze
Registered
Damn Boosted, you are a freakin Busa Jedi!!!
This is an interesting thread!
ali123
Banned
I hope it doesnt just stop here...
Got a it apart. It’s a head scratcher as there’s no one thing I see as a definite root cause. But rather a bunch of issues.
Pistons definitely show detonation. New rings were put in at one point, but not gapped. They cylinders have excessive wear at the top, probably cause from the pistons rocking from detonation. But the cylinders are so shiny from wear I’m believe that’s where the loss in compression is coming from. It looks like number 2 cylinder is cracked... I’m sure I’m missing something.
Pistons definitely show detonation. New rings were put in at one point, but not gapped. They cylinders have excessive wear at the top, probably cause from the pistons rocking from detonation. But the cylinders are so shiny from wear I’m believe that’s where the loss in compression is coming from. It looks like number 2 cylinder is cracked... I’m sure I’m missing something.
Nastee
Registered
This is making me sad & not even mine. Boosted will get her right & tight though.
busakiller
Registered
We talked about a couple options. Nothing set in stone yet. But it will be getting fixed.
ali123
Banned
this is getting like a dr. Phil episode..... getting you guys to open up.
give them some room @Ali! This is a big unexpected cost, people got to weigh options. let the man think will ya?
ali123
Banned
tell us PHIL.... what are the options?
