I heard you guys like engine tear downs.

[Racer x]

Sounds like the exhaust is full of fuel and just went boom.

[HoneyBadgerRy]

45psi on left cylinder.

Either the exhaust valves are open, the rings are stuck, or a valve is bent.

The timing is set correctly, I can't imagine 0.005" being enough to effect the timing that much. I guess I can force air into the combustion chamber and see if it goes out the crankcase, intake valves, or exhaust valves.

[HoneyBadgerRy]

Air flows through the exhaust valves. Exhaust vales must be bent. I need either a new complete head or a new motor.

I'll most likely pickup a used motor bore it 2mm slap forged high comp pistons in it and call it a day. Newgen or Pregen motor, idk.

[Motofool]

Originally Posted by HoneyBadgerRy

Air flows through the exhaust valves. Exhaust vales must be bent..........

Did you service the valves while the head was out?

Maybe just replacing the valves or lapping the seats?

Any engine rebuilding shop can fix those problems.

[HoneyBadgerRy]

Originally Posted by Motofool

Did you service the valves while the head was out?

Maybe just replacing the valves or lapping the seats?

Any engine rebuilding shop can fix those problems.

Being that its a b**** to take the valves out I chose not to this time. The motor ran and started like a champ until I took it apart (the second rebuild), so the valves and seats should be fine. Its not like the machining heated them up so much they warped. I am fairly confident that a valve grind and lap will not fix my problem.

[RacinNinja]

Originally Posted by HoneyBadgerRy

Being that its a b**** to take the valves out I chose not to this time. The motor ran and started like a champ until I took it apart (the second rebuild), so the valves and seats should be fine. Its not like the machining heated them up so much they warped. I am fairly confident that a valve grind and lap will not fix my problem.

You're not even going to look?

[HoneyBadgerRy]

Originally Posted by RacinNinja

You're not even going to look?

Pretty much. It's not like without the ninjette I don't have access to a bike. Its a fun bike, but I'm not going to stress out about it. I'll just ride something else.

I have so much stuff to worry about right now, my street bike not running isn't high on my priority list.

[Ghostt]

Third time a charm, or is this fourth or fifth?

Rebuilding engines are easy. ...... Like carburetors

J/K

[HoneyBadgerRy]

I'll be honest, this is by far the worse luck I've had with a motor, but I'm really not freaking out about it.

[HoneyBadgerRy]

I took the head off today for nothing more than I was bored as hell. You can visually check and see all valves are shut, preform a leak down test, and it leaks are rapidly. On a compression test it made 45 psi. Take the head off, visually checks out, pour water in the combustion chamber, and it holds. Well if that isn't confusing... I guess I can lap the valves, but there is no way water can hold, but the motor can only make 45psi. I guess timing is off even though its visually on at 2T.

[RacinNinja]

Did you ever pull the barrels and look at the rings or pistons?

[HoneyBadgerRy]

Originally Posted by RacinNinja

Did you ever pull the barrels and look at the rings or pistons?

I didn't, however the tops of the pistons look heathy. I cleaned up the head and put it back on. It feels like it has compression, but it didn't start right up. I didn't really mess with it.

[juliusmichaelhonrada]

Originally Posted by HoneyBadgerRy

Didn't touch anything, no starting fluid, turn the bike on and thumb the starter for a second (because you never know, maybe the left carb just didn't fuel correctly).

AFTERFIRE. It poped so loud it wasn't even funny.

I've heard salt of afterfire, but this was loud. It happened 10 minutes ago and my ears are still pulsing and ringing.

Trying to think about what that means... Timing? I can't imagine it being compression. Maybe fueling? If it was timing it should have done it yesterday though, because nothing has changed.

Afterfire happened to me when i have a goofy timing , the P.O swapped the intake cam and had put it in the ex cam ,and vice versa and when i see 2|T in the flywheel the marks on the cam is facing the sky . and when i checked the spark plugs on the CYL #1 where is the afterfiring is happening the spark plug have no gap at all.

[HoneyBadgerRy]

I have checked the timing like ten times, I might have had it messed up before, but the can with the but next to the ex is timed at 2t for the exhaust valves, and the can with the bolt near the IN is timed at 2t on the intake valves. Everything is straight.

For curiosity sakes I swap the plug wires and it after fires every couple of revolutions, so I'm going to say its safe to say the ignition timing is correct. Also, that was a stupid test.

[juliusmichaelhonrada]

Originally Posted by HoneyBadgerRy

I have checked the timing like ten times, I might have had it messed up before, but the can with the but next to the ex is timed at 2t for the exhaust valves, and the can with the bolt near the IN is timed at 2t on the intake valves. Everything is straight.

For curiosity sakes I swap the plug wires and it after fires every couple of revolutions, so I'm going to say its safe to say the ignition timing is correct. Also, that was a stupid test.

might also want to check the carb air fuel mixture, it might not be able to burn the mixture and it accumulates in the exhaust then a wasted spark and boom, i am not that good , im just sharing my experience on afterfire and how i fixed mine

[HoneyBadgerRy]

Originally Posted by juliusmichaelhonrada

might also want to check the carb air fuel mixture, it might not be able to burn the mixture and it accumulates in the exhaust then a wasted spark and boom, i am not that good , im just sharing my experience on afterfire and how i fixed mine

Nothing has changed in the carbs since I took it apart, and when I took it apart the only problem was the warped head.

[HoneyBadgerRy]

So with farther inspection turning the motor over by hand with the cct set the cam chain changes tension. It gets pretty sloppy at one point. The only thing I can imagine that would cause this is side to side movement of the cam gears.

What would cause this? Well warped camshafts could. Warped cam caps could. A seriously warped head could.

How would you check what it is? I don't really know. The exhaust cam has a tiny bit of coloration on it, so it must of gotten hot.

The right thing to do would be a new head, new valves, new cams, new rockers, new cam guides, etc. However being that would cost a fortune, I will likely buy a head assembly from eBay. I found on for the tune of $100, not sure if it includes rocker arms. I might buy it, hook it up, see if it works, and if it does just tear it down and rebuild the head, clean it up, port, etc when I bore the cylinders out.

[HoneyBadgerRy]

So before I order the head I explicitly asked them if it came with all eight rockerarms. (Because I wanted the cams, head, can caps, and rocker arms all to be mated to each other and no warp.) They replied back that it cake with all eight. I recive the package, and due to their horrible packaging it had three bent can cap bolts (not a big deal, I'll replace them), the head bolts might have Ben bent, so I tossed them, there was a questionable can cap bolt, tossed it. I start disassembling the head and guess what? Six F***ing rocker arms!

If they just told me it had six roxkerarms I would likely still have ordered it, and I would have been happy, but no they explicitly lied to me!

Side note, looking at the head, the casting is much cleaner than the head that came off of my bike. I believe the head was off of a 1988. Its interesting that the castings got worse over time.

[CaliGrrl]

Ugh. I'd be cranky at that, too. Things should arrive complete and undamaged.

[choneofakind]

If you have it in writing, demand money back. Writing is king, yo.

Originally Posted by HoneyBadgerRy

Side note, looking at the head, the casting is much cleaner than the head that came off of my bike. I believe the head was off of a 1988. Its interesting that the castings got worse over time.

Cleaning up cast parts cost money. Doing less cleanup = cheaper part.

[HoneyBadgerRy]

Originally Posted by choneofakind

If you have it in writing, demand money back. Writing is king, yo.



Cleaning up cast parts cost money. Doing less cleanup = cheaper part.

Even where they didn't clean it up. Like the roughness on the seam of the intake ports. Its all around a cleaner cast. They must have just quit caring as much about good cast and used bad forms to make cheap heads.

[choneofakind]

Yeah man, they likely wanted to spend as little time and money as possible on these bikes. They didn't even change them until 2007, I doubt they're going to spend any more time than absolutely necessary on any individual part.

[juliusmichaelhonrada]

hi , how are things going , im having problems with my engine too and i want to tear down the head to see the valves and rings , it seems like my cyl #2 is dying/misfiring , i checked all electrical things and all was perfect , so im only down to the engine compression

[juliusmichaelhonrada]

just tell me how to remove that cam chain guides and i will tear down my motor tomorrow first thing in the morning

[HoneyBadgerRy]

I finally got time off work, so I put it together, but I appear to have the timing off a click, so I didn't even turn the motor over.
@juliusmichaelhonrada
The Can chain guides are pretty simple, first remove the cams, rocker arms, and cam caps. Second grab the front cam chain guide and pull it straight up. Third take a 12mm t handle (you can use whatever, I prefer a t handle or a ratchet for this) and take off the 13mm bolt on the top back of the right side if the head. Slide out a pin, you might need to use pliers. Slide the back can chain guide forward (you don't need to take it out to take the head and pistons off.

I would then remove the head bolts, the oil hose, and the head bolt on the bottom (10mm). Take the exhaust and head bracket off and pull the head off. If you need pictures I'm sure I could dig something up.

[juliusmichaelhonrada]

Originally Posted by HoneyBadgerRy

I finally got time off work, so I put it together, but I appear to have the timing off a click, so I didn't even turn the motor over.
@juliusmichaelhonrada
The Can chain guides are pretty simple, first remove the cams, rocker arms, and cam caps. Second grab the front cam chain guide and pull it straight up. Third take a 12mm t handle (you can use whatever, I prefer a t handle or a ratchet for this) and take off the 13mm bolt on the top back of the right side if the head. Slide out a pin, you might need to use pliers. Slide the back can chain guide forward (you don't need to take it out to take the head and pistons off.

I would then remove the head bolts, the oil hose, and the head bolt on the bottom (10mm). Take the exhaust and head bracket off and pull the head off. If you need pictures I'm sure I could dig something up.

thank you , that exhaust cam is pretty stubborn , it took me 3 attempts to finally perfect it , you cant line the exhaust cam mark in the surface gasket because somehow the lobes is hitting the rocker arm and will just push it out of timing everytime you try to bring back the cam caps. i remember vividly that i moved the 2t mark and its not lined up in peephole and i put exhaust cam in a position where it wont hit a rocker arm the ex mark is a bit higher than the gasket surface, then the intake cam mark a bit down below the gasket line . when i put everything back together and rotate the crank by hand when 2T lines up in the peephole the in /ex mark will also line up with the gasket surface , that way the cam caps is already torqued down , and the cam chain tensioner is installed and in action. also theres 33 rivets in teh cam chain

[juliusmichaelhonrada]

i had a huge disaster , my radiator hose that connects the thermostat to the engine head ruptured while i was on way somewhere , fan didnt work too temperature gauge didnt reach Redline , my spark plug holes were full of coolant , i was fixing the bike beside a busy road , good thing the radiator hose was long enough all i did was cut the ruptured part and put it back together just so i can go home i refilled the radiator with water.

Bad thing is only cylinder 1 is running and theres no spark in cylinder 2 , did made it home with 1 cylinder , the bike is so slow and wont rev past 6k rpm.

When i got home i removed the spark plug cap , its full of coolant i did wait for it to dry up, fixed the fan (fuse was just loose fan is modified with a on/off switch) the bike wouldn't start now its like it almost want to start but then backfires , i believe my engine is flooded with fuel because of running only with 1 cylinder or the spark plug is broken because of the coolant ? , i dont know but its highly unlikely that its the timing, i also notice coolant came out on the left side of the engine block where there is a small hole that seems like connected to the spark plug hole