In need of engine advice, 2006 NE5

StripeySnake

New Member
Local time
12:16 PM
Joined
Jul 3, 2024
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Location
Massachusetts
Hi everyone,
I recently disassembled the engine from my 2006 NE5, and I found vertical grooving in the cylinder wall, as well as a lot of carbon buildup. I am unfortunately pretty new to small engines and motorized bicycles and I'd like to do my best to take better care of my whizzer as it means a lot to mean and I am aware not too many NE5s were made in the grand scheme of things. The current engine modifications are as follows:

minor increased compression with stock NE head (unfortunately my machinist followed my instructions incorrectly so the head was only decked by about .035")
flattened cylinder head with reground valve seats
dremeled restrictor plate & removed intake sleeve to match 22mm carburetor
Camshaft Timing advance 1 tooth
Taiwan made Mushroom lifters
Black cylinder paint for improved heat dissipation

My current plan is to try to find a machine shop or mechanic locally that can bore out my cylinder and switch to an oversize piston and new rings (does anyone know where I can find an oversize piston? thanks.). I've also seen mention of a crankshaft spacer being important, and I would like to get one figured out before I do much more with the engine. My crankshaft does not have an egregious amount of play, but it does move back and forth about half a millimeter if I tug on it. I have noticed a barely audible scraping sound on occasion when running past 5000 rpm for an extended period of time, I wonder if that is related to the cylinder gouging. Additionally, the engine picks up a nasty ticking sound at about 6500 rpm but I don't hit that on the road anyway. Might be valve float. Upon inspection my camshaft looks mostly ok, but the surfaces of the mushroom lifters appear polished but not quite flat. Because of this I am thinking of drilling a perfectly vertical hole in a piece of wood and using it alongside some sandpaper on an old marble slab to grind the lifters flat. Once I've worked out all the kinks, I figure I should take the whole engine apart, clean everything religiously, and then re assemble in as clean an environment as possible.
As for oil, I have tried several different synthetic 40 weight oils but have currently settled on a conventional 50wt non detergent racing oil with pre added zinc. If there is a better option please let me know, I don't mind getting called an idiot for running the wrong oil I would rather know so I don't make the mistake again. I am concerned the cylinder will get gouged again after the rebuild and I can't exactly keep getting oversized pistons indefinitely.

The last thing I wanted to ask about has to do with an old cylinder head sold by Quentin Guenther I recently got my hands on. I believe it was marketed as a "tri pattern" head and was based on the vintage whizzer hi fin design but adapted to early NE stud pattern. I would love to use this head on my engine, but the early NE uses 8mm head bolts in the place of the two 10mm bolts used in the later NE design. Because of this I would either need to modify the head (considering how rare and special it is I would rather avoid doing this at all cost) or to use 10mm to 8mm stepped studs and 8mm head bolts. Stepped studs seem like the best option but I am not 100% sure if they can be trusted. I will make sure to use steel ones of course. The other issue I have noticed is that the valves make contact with the head when it is sat on top of the cylinder. This is only by about 1mm and I tested it with the head just sitting loosely to avoid damaging anything. I imagine that carefully grinding the top of the valves down a couple millimeters could easily solve the problem without affecting how they seat into the head, but I wanted to ask for advice since I am no expert on engine modifications.
Thank you for your time and have a great day!

-StripeySnake

P.S. I am happy to send pictures of anything mentioned if it will help.
 
@Wrench is your Engine Expert here. He will chime in soon if he is not on vacation. My experience on the Whizzer engines is limited when it comes to machining work. I have had Quentin prepare and work my Westman Cast Iron Cylinder and my SE Engine machining on my 2008 Ambassador rebuild.
 
Hi everyone,
I recently disassembled the engine from my 2006 NE5, and I found vertical grooving in the cylinder wall, as well as a lot of carbon buildup. I am unfortunately pretty new to small engines and motorized bicycles and I'd like to do my best to take better care of my whizzer as it means a lot to mean and I am aware not too many NE5s were made in the grand scheme of things. The current engine modifications are as follows:

minor increased compression with stock NE head (unfortunately my machinist followed my instructions incorrectly so the head was only decked by about .035")
flattened cylinder head with reground valve seats
dremeled restrictor plate & removed intake sleeve to match 22mm carburetor
Camshaft Timing advance 1 tooth
Taiwan made Mushroom lifters
Black cylinder paint for improved heat dissipation

My current plan is to try to find a machine shop or mechanic locally that can bore out my cylinder and switch to an oversize piston and new rings (does anyone know where I can find an oversize piston? thanks.). I've also seen mention of a crankshaft spacer being important, and I would like to get one figured out before I do much more with the engine. My crankshaft does not have an egregious amount of play, but it does move back and forth about half a millimeter if I tug on it. I have noticed a barely audible scraping sound on occasion when running past 5000 rpm for an extended period of time, I wonder if that is related to the cylinder gouging. Additionally, the engine picks up a nasty ticking sound at about 6500 rpm but I don't hit that on the road anyway. Might be valve float. Upon inspection my camshaft looks mostly ok, but the surfaces of the mushroom lifters appear polished but not quite flat. Because of this I am thinking of drilling a perfectly vertical hole in a piece of wood and using it alongside some sandpaper on an old marble slab to grind the lifters flat. Once I've worked out all the kinks, I figure I should take the whole engine apart, clean everything religiously, and then re assemble in as clean an environment as possible.
As for oil, I have tried several different synthetic 40 weight oils but have currently settled on a conventional 50wt non detergent racing oil with pre added zinc. If there is a better option please let me know, I don't mind getting called an idiot for running the wrong oil I would rather know so I don't make the mistake again. I am concerned the cylinder will get gouged again after the rebuild and I can't exactly keep getting oversized pistons indefinitely.

The last thing I wanted to ask about has to do with an old cylinder head sold by Quentin Guenther I recently got my hands on. I believe it was marketed as a "tri pattern" head and was based on the vintage whizzer hi fin design but adapted to early NE stud pattern. I would love to use this head on my engine, but the early NE uses 8mm head bolts in the place of the two 10mm bolts used in the later NE design. Because of this I would either need to modify the head (considering how rare and special it is I would rather avoid doing this at all cost) or to use 10mm to 8mm stepped studs and 8mm head bolts. Stepped studs seem like the best option but I am not 100% sure if they can be trusted. I will make sure to use steel ones of course. The other issue I have noticed is that the valves make contact with the head when it is sat on top of the cylinder. This is only by about 1mm and I tested it with the head just sitting loosely to avoid damaging anything. I imagine that carefully grinding the top of the valves down a couple millimeters could easily solve the problem without affecting how they seat into the head, but I wanted to ask for advice since I am no expert on engine modifications.
Thank you for your time and have a great day!

-StripeySnake

P.S. I am happy to send pictures of anything mentioned if it will help.
Howzit,

Oversized Piston - New Edition Whizzer parts are harder to find today
Call Quenton ( Master Whizzer Technician) @ 252-475-0406 he might have what you need
Or contact Weisco and see if they can match a Whizzer piston
I see pistons on E Bay with valve pockets, If the wrist pin to top of piston measures the same, It'll still work

I suggest you take the new piston and rings with you to the machine shop They will want to measure and fit the piston to the cylinder

Piston Ring End Gap
Minimum .011"
Max .018"
Make the PREG .012"

Scraping Noise:
Look to see if the cam gear is rubbing on the crank weight - you'll see scrap marks on the crank weight
If so you'll need to shim the crank end play

Which RH side cover crank bearing do you have?
1) Needle bearing 2012
I've been told to drop pennies inside the bearing to shim the crank end play until the cam gear don't rub the crank weight
2) Roller Bearing 6904
1mm shim goes behind the 6904 bearing - pull bearing install shim then press a NEW bearing back in
DSCF0131.JPG
If bearing is shielded REMOVE shields - Oil lubrication = OPERN BEARING

Valves hitting Head:
Measure valve lift height off the cyl deck - stock valve lift height is .250"
Mill head combustion chamber valve pockets deeper
 
Hi everyone,
I recently disassembled the engine from my 2006 NE5, and I found vertical grooving in the cylinder wall, as well as a lot of carbon buildup. I am unfortunately pretty new to small engines and motorized bicycles and I'd like to do my best to take better care of my whizzer as it means a lot to mean and I am aware not too many NE5s were made in the grand scheme of things. The current engine modifications are as follows:

minor increased compression with stock NE head (unfortunately my machinist followed my instructions incorrectly so the head was only decked by about .035")
flattened cylinder head with reground valve seats
dremeled restrictor plate & removed intake sleeve to match 22mm carburetor
Camshaft Timing advance 1 tooth
Taiwan made Mushroom lifters
Black cylinder paint for improved heat dissipation

My current plan is to try to find a machine shop or mechanic locally that can bore out my cylinder and switch to an oversize piston and new rings (does anyone know where I can find an oversize piston? thanks.). I've also seen mention of a crankshaft spacer being important, and I would like to get one figured out before I do much more with the engine. My crankshaft does not have an egregious amount of play, but it does move back and forth about half a millimeter if I tug on it. I have noticed a barely audible scraping sound on occasion when running past 5000 rpm for an extended period of time, I wonder if that is related to the cylinder gouging. Additionally, the engine picks up a nasty ticking sound at about 6500 rpm but I don't hit that on the road anyway. Might be valve float. Upon inspection my camshaft looks mostly ok, but the surfaces of the mushroom lifters appear polished but not quite flat. Because of this I am thinking of drilling a perfectly vertical hole in a piece of wood and using it alongside some sandpaper on an old marble slab to grind the lifters flat. Once I've worked out all the kinks, I figure I should take the whole engine apart, clean everything religiously, and then re assemble in as clean an environment as possible.
As for oil, I have tried several different synthetic 40 weight oils but have currently settled on a conventional 50wt non detergent racing oil with pre added zinc. If there is a better option please let me know, I don't mind getting called an idiot for running the wrong oil I would rather know so I don't make the mistake again. I am concerned the cylinder will get gouged again after the rebuild and I can't exactly keep getting oversized pistons indefinitely.

The last thing I wanted to ask about has to do with an old cylinder head sold by Quentin Guenther I recently got my hands on. I believe it was marketed as a "tri pattern" head and was based on the vintage whizzer hi fin design but adapted to early NE stud pattern. I would love to use this head on my engine, but the early NE uses 8mm head bolts in the place of the two 10mm bolts used in the later NE design. Because of this I would either need to modify the head (considering how rare and special it is I would rather avoid doing this at all cost) or to use 10mm to 8mm stepped studs and 8mm head bolts. Stepped studs seem like the best option but I am not 100% sure if they can be trusted. I will make sure to use steel ones of course. The other issue I have noticed is that the valves make contact with the head when it is sat on top of the cylinder. This is only by about 1mm and I tested it with the head just sitting loosely to avoid damaging anything. I imagine that carefully grinding the top of the valves down a couple millimeters could easily solve the problem without affecting how they seat into the head, but I wanted to ask for advice since I am no expert on engine modifications.
Thank you for your time and have a great day!

-StripeySnake

P.S. I am happy to send pictures of anything mentioned if it will help.

Inspect the centrifugal clutch, that could also be another possibility where the scraping noise is coming from
BTW put a fingernail size amount of grease on the one way bearing,

As for using the "Q" head with all 8mm bolt holes - a few possibilities
1) Put 8mm Heli Coil in the cylinders two 10mm bolt holes
2) Drill head for 10mm bolts
3) 10mm to 8mm step studs
 
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