Author Topic: Icy Bikes - '76 CB400f resto - getting ready to change out the transmission (Read 13341 times)

MCRider · « **Reply #25 on:** February 16, 2013, 06:08:30 AM »

I believe its called: 1/8" NPT. This is a tapered pipe thread. A standard size bolt will not thread in. Only a NPT plug or the sender itself.

Dream750 · « **Reply #26 on:** February 16, 2013, 07:50:18 AM »

Quote from: zachz on February 13, 2013, 01:07:48 PM

Still never had anyone answer the question on the proper screw size for the oil pressure switch - so if anyone knows.

Honda and other Japanese manufacturers used (British Standard) 1/8” BSPT 28 TPI for the oil pressure switch threads in their motorcycles and cars. The common 1/8” NPT 27 TPI will usually work going into aluminum. But it’s definitely not the correct thread size and could leak. $:-\$

zachz · « **Reply #27 on:** February 16, 2013, 10:13:49 AM »

Thanks guys - just to make sure - that is the thread for the screw that holds the electrical wire to the oil pressure switch?

MCRider · « **Reply #28 on:** February 16, 2013, 10:27:19 AM »

Quote from: zachz on February 16, 2013, 10:13:49 AM

Thanks guys - just to make sure - that is the thread for the screw that holds the electrical wire to the oil pressure switch?

No, what I posted was the thread of the sender itself into the crankcases.

After posting I thought to myself, maybe he means the screw that holds the wire on? Sure enough. I'll check mine. Coincidentally i just bought an OEM sender and it has the screw with it.

MCRider · « **Reply #29 on:** February 16, 2013, 11:00:58 AM »

The screw that holds the wire on is (from my original sender ca 1972) 4 x .7 x 6mm long. The one that came with the new OEM sender I just bought is also 4 x .7 but 8mm long. Both have lock washers on them.

zachz · « **Reply #30 on:** February 16, 2013, 03:25:10 PM »

Thank you sir! I suspected that the originally quoted sizes were for the sender unit rather than the wire. I'll see what I can find (though perhaps ignorance is bliss - probably not long as far as the engine is concerned, however).

Dream750 · « **Reply #31 on:** February 16, 2013, 07:11:22 PM »

Quote from: zachz on February 16, 2013, 03:25:10 PM

Thank you sir! I suspected that the originally quoted sizes were for the sender unit rather than the wire. I'll see what I can find (though perhaps ignorance is bliss - probably not long as far as the engine is concerned, however).

Yes, It’s the wire screw size you wanted.

Must have been a reading comprehension problem on my end.

The short screw that MCRider described is still available from Honda, part no: 93500-04005-0A

zachz · « **Reply #32 on:** February 19, 2013, 11:28:37 AM »

I'd looked through the 400f parts fiche and didn't see the screw listed separately, but I appreciate the heads up!

Now to make some room in the garage and move the bike forward from it's winter slumber.

zachz · « **Reply #33 on:** March 18, 2013, 09:36:49 PM »

In the midst of replacing steering bearing with tapered roller bearings. Front stem removed:

Naked by z5, on Flickr

zachz · « **Reply #34 on:** May 24, 2013, 08:22:15 PM »

Long overdue update. Got the bike reassembled with the new clutch plates, headlight bucket, switches and other bits that id collected over the winter. The starter switch was used but the harness unhacked and start button was still functional when I'd received it. Unwisely I pressed the button while the handle bar control was open, which brought the partial demise of the switch housing. Trying to be creative, I found that packing the space behind the starter switch assembly in the RH control restored the starter switch function. Mostly. Some additional reengineering will be required. After sitting all winter, the engine fired up on the third kick with little drama.

After a final safety check to ensure everything was snugged up properly, I took the bike out for the first time his season on Wednesday. Made it three blocks before something in the clutch loosened and the clutch lever stopped returning. Two steps forward, one step back.

zachz · « **Reply #35 on:** May 01, 2014, 03:42:03 PM »

Been a long time. On the road and generally running well, though need to repair the cam chain tensioner bolt that sheared off last year.

Purchased and installed a set of Hagons from Dave Quinn Motorcycles.

Saw this guy yesterday morning as I was warming up my bike. Thankfully he wasn't too interested in me.

Untitled

zachz · « **Reply #36 on:** August 21, 2014, 04:38:00 PM »

Been having a few small issues with my charging system. Noticed that I'm generally getting poor charging, however had the main fuse pop on my way to work yesterday morning. Have yet to fully diagnose - but wondering what my charging system should limit out at with the regulator? A quick measurement with the DVOM when I got the bike home yesterday evening indicated voltages in excess of 14.8 when I'd rev it up to 3-4k rpm.

calj737 · « **Reply #37 on:** August 21, 2014, 04:43:52 PM »

In excess of 14.8 is a problem. Very likely your fuse blowing is related. Voltage that high, or higher, will damage your battery. Is your regulator and rectifier the stock units? If so, you need to commence diagnosing the regulator for faults, then verify the rectifier.

zachz · « **Reply #38 on:** August 21, 2014, 04:49:27 PM »

I'll need to double check the actual - it was bouncing around 14.7-14.8 and I didn't want to push it too far due to the later evening hour and knowledge that yes, the fuse going was most certainly related.

Both units are stock and are up for testing next.

tjgstevens · « **Reply #39 on:** August 24, 2014, 02:53:37 PM »

new here but been working on motor cycles for over 20 years.
The honda factory manual for the 350-400 states:
1000 rpm 12.5 volts 1.6 amps day
2000 rpm 14.4 volts 1.9 amps day
3000 rpm 15 volts 2.0 amps day 4 amps night (with lights on)
4000 rpm 15 volts 1.8 amps day 2.6 amps night (with lights on)
5000 rpm 15 volts 1.6 amps day 2.0 amps night (with lights on)
6000 rpm 15 volts 1.5 amps day 1.6 amps night (with lights on)
7000 rpm 15 volts 1.4 amps day 1.4 amps night (with lights on)
8000 rpm 15 volts 1.4 amps day 1.4 amps night (with lights on)

most charging systems on cars, trucks and motorcycles run at 14.8v

hope this helps !!

zachz · « **Reply #40 on:** August 26, 2014, 06:37:44 PM »

Thanks. Was 15.2 + following a quick test over the weekend.

tjgstevens · « **Reply #41 on:** August 30, 2014, 07:29:15 PM »

as long as you are under 16v you should be ok

2strokeTrush · « **Reply #42 on:** August 31, 2014, 07:01:48 AM »

Very nice looking!

zachz · « **Reply #43 on:** March 12, 2015, 05:49:56 PM »

So new question - what gasket sets do I need to have on-hand before pulling my 400f engine to swap out the transmission? I've got a new transmission onhand but don't want to crack the case until I've got everything I need to reassemble.

calj737 · « **Reply #44 on:** March 12, 2015, 05:52:34 PM »

Clutch cover and oil pan if you aren't taking the top end down.

zachz · « **Reply #45 on:** March 12, 2015, 06:00:08 PM »

Dumb question - I don't have to crack the case to pull both sections of the transmission? The 350/400 manual has me thinking that, but I'll be happy to be wrong.

calj737 · « **Reply #46 on:** March 12, 2015, 06:04:02 PM »

It seems to me that you could invert the engine and remove the lower half to expose the transmission. But you will be splitting the case

MoMo · « **Reply #47 on:** March 12, 2015, 06:47:21 PM »

Quote from: calj737 on March 12, 2015, 06:04:02 PM

It seems to me that you could invert the engine and remove the lower half to expose the transmission. But you will be splitting the case

Just invert as Cal said. Wise idea to order any lower end seals too...Larry

zachz · « **Reply #48 on:** March 26, 2016, 11:09:14 PM »

Only took a year but getting around to it -

Sent from my iPhone using Tapatalk

MoMo · « **Reply #49 on:** March 27, 2016, 03:24:49 AM »

Guess you decided to disassemble the entire motor??....Larry

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Author Topic: Icy Bikes - '76 CB400f resto - getting ready to change out the transmission (Read 13341 times)