[CXPHREAK]

Just a thought, could it have some sort of diode? And measuring resistance in the other direction will give a different number?

Though I think randomness says I've already done this.

 

[D-Fresh]

Phreak,

You obviously know what you are doing and have done multiples of this type of thing and it works out but being a toolmaker for 20 years i cringe at using a "flapwheel" sander to make a precision bore, I guess you are that good! I have visions of using a Bridgeport and boring head to do that type of operation but i don't have access to that type of equipment anymore since i'm out of that line of work now and will have to use that method myself when i get to that point.

 

[Sidecar Bob]

Just a thought, could it have some sort of diode? And measuring resistance in the other direction will give a different number?

I was wondering that myself.

Re flap wheel & precision: Any method of opening up the bore is only as precise as the person doing it is careful. Since most of us don't have access to the proper equipment (or the funds to have it done at a machine shop that does) the flap wheel method has been used many times since just after the difference between early & late seals was first realized by people on a predecessor of this forum over 15 years ago. The trick is to run the flap wheel in the bore just a few seconds, measure and run it again until the desired opening is achieved.

 

[CXPHREAK]

The flap wheel is an imprecise method to do a relatively precision job but I've only ever Shepped the first one I did on my 500C when I got it 11 years ago.

I don't actually know how many hogouts I've done now. Quite a few. Never a leak or a problem.

I would use my drillpress, but it's small size makes it near impossible to get a cover positioned on the deck.

Also, the design of the mech seal will allow it to compensate for minor degrees of linear alignment and concentricity issues.

Bob, I'll measure in both directions when I lock the shed shortly.

 

[Reg in Bristol]

My GL gauge has a resistance of 48 ohms and if I apply 7V across it
(7V one side, ground the other) form my bench power supply,
I see the needle climb and the supply shows it using about 120 mA.

If disconnect the ground wire and measure the voltage either side of the gauge
its the same as you'd expect

I wouldn't be surprised to see 6.45V if one end was connected to the sender at 20C or so
which can be circa 600 ohms at 20C as i recall

Using Marks gauge resistance of 38 ohms and a guess at 600ohms for the sender

V out = VsxR2/R1 + R2

that's 7x600/38+600

or 4200/638 = 6.58V

 

[Sidecar Bob]

You're absolutely correct and here's the problem: I misread and thought that the sender was 38 ohms (it was the end of a long day).

Here's what I should have said:

You know the resistance of the gauge (Rg) and the voltage (7.04V). Measure the resistance of the sender (Rs)

[Rs / (Rs + Rg)] x 7.04 = Voltage across sender. (This is the same formula Reg used but turned around a bit)

I'll bet the sender is close to 415.4 ohms when the voltage across it is 6.45V

(I have added a correction where I posted it last night)

 

[CXPHREAK]

Thanks fellers. That's the great thing about this place - someone generally knows the stuff I don't and you've likely helped me retain my sanity.

I could never grasp equations at school, maths not being my strongpoint. I was actually booted out of maths class for asking what equations could be used for. It was an honest question.

The gauge does measure the same in both directions. The sender was indeed connected ... and 600 something ohms when checked. This seems pretty typical of all the senders here measured at ambient temperature.

Here's a few photos I took including my cleaned up headlight shell/wiring.

 

[CXPHREAK]

And some perty new bores. Still awaiting a detergent bath to get rid of the honing oil, [email protected] and general detritis.

I will likely assemble this as a short motor this weekend. And then it'll be waiting for a set of heads to be ported and built.

 

[murrayf]

run a tap down all those bolt holes and blow them out

 

[CXPHREAK]

Will do Murray.

I don't have a tap for the head bolt holes but I do have a headbolt I've cut flutes in.

Thanks for the heads up on which sleeves to use.

 

[CXPHREAK]

Block detergent washed with stinking hot water straight from our shower on the massage setting. This gives 3 solid high pressure jets. Scrubbed with tooth brushes and spraygun cleaning brushes. Blown dry and cylinders oiled.

Have just finished measuring for mains. Block is 47.1. The crank cap that came with the crank {thanks JC} measures 47 even. As the mains that came with this crank have nothing wrong with them I'll use these. This block works out at black mains - a size I only have 2 new bearings in.

Now, onto chasing out all the bolt holes.

 

[CXPHREAK]

Crank and rear gearbox bearings.

I started assembling the thingummy motor this weekend.

After resleeving the block was given a hot detergent wash as outlined above. Before starting assembly yesterday I blew it out with 2 cans of aerosol degreaser, blew everything out with the compressor gun and then white rag wiped it out.

First thing was to fit the new gearbox bearings that live in the engine block.

I found that my tool for installing lower steering bearings into the frame to be the correct size for the 6205 and with the thick washer from a tapered bearing kit also drove in the 6204.

The bearings go here.

Fit the oil lock piece that sits behind the 6204.

Followed by both bearings.

The seals were removed before proceeding with adding the gearbox. Honda left a seal behind the 6204 so I did too.

 

[CXPHREAK]

Crank and gearbox.

This is my main bearing press. Kindly made for me by Ralph.

 

[CXPHREAK]

I elected to fit new main bearings. I went with brown which the measurement {between 3 and 4 thou} should give an oil clearance of about 1.75 thou

 

[CXPHREAK]

Pistons, rods etc.

Here's the bits to be assembled in this step.

Piston fitted to rod. A grade used piston pin {aftermarket replacements weigh 20 or so grams more than these, so weren't used.} And new piston pin clips. New yellow rod bearings.

Ring gaps are all 6 thou out of the packet.

Cover bolts to protect crank journals while fitting. I had some trouble with this step with access. I realised later that I normally ignore the FSM recommendation to set the motor at TDC for each piston insertion. BDC gives much better access for fitting the caps and bolts as well as torque wrench access.

Rods are fitted to pistons so that the oiler hole faces the engine centreline and the 'in' is at the back of the piston.

Rings fitted to piston. The rings are rings we've had made. They are the same ones fitted to the motor in the bike I am currently riding.

 

[murrayf]

to shiny

go get that stuff oily and dirty!

 

[CXPHREAK]

I had already rebuilt this transmission, but didn't replace any bearings at the time. Here, I've dismantled this one only far enough to replace the 6305 bearing on the mainshaft.

I think I'll just let the pictures tell the story here.

One note on the 6204 bearing fitted earlier. I found this caused the secondary shaft to bind a little. I removed the transmission and investigated. At first I thought the bearing hadn't seated all the way into the block. Checked that. No different. Looking at an old bearing compared to the new the old bearing has more of a rounded shoulder than the new one, so seats .10 mm deeper.

Rather than pull this bearing back out and chamfer one edge I decided to remove the .10 from the thrust washer that fits against this bearing. Binding fixed - but only after having the transmission in and out about a dozen times for test fits.

I have more of these trans to fit bearings to when they are fitted to motors. In future I'll bevel the bearing before fitting it. And before removing the bearing seals.

 

[CXPHREAK]

A note on the couple of bearings not replaced here. In the front of the trans is a smallish roller bearing. These are unavailable. I do have a couple of crowded roller bearings in this size from Honda dirtbike suspension, but as they are a different type of bearing I don't know their suitability. I will install one and check it out at some point, but not in this motor. Fortunately, these bearings generally seem to be in good condition.

I didn't even try to source any shift drum bearings as they live an easy life and generally seem to be good for reuse.

 

[CXPHREAK]

 

[CXPHREAK]