750-900-1100 differences between engine covers

Posted: Fri Jan 27, 2012 2:26 pm

I am going to have some powder coating done on engine covers on my 1100 motor / Junior project (AKA Sybil.) I plan on using a cam cover, starter cover, ignition (timing and starter gear / engine) cover and counter shaft sprocket cover off an old 750 motor I removed from Shakey. I will use the clutch cover from the 1100. I plan on trying to temporarily install the 750 clutch cover on the 1100 so the motor is not exposed to the air while the powder coating is done.

Are there any differences between the 750 and 1100?

Posted: Fri Jan 27, 2012 2:42 pm

Yes, not all the starter gear covers, ignition covers have the same thread where they screw together. Also there are some variations in the valve covers. Test fit before you spend the money.

Posted: Fri Jan 27, 2012 3:35 pm

Umm...

They are all the same, with minor changes in the outside finishes (fins, ect)
All the valve covers are the same, timing, alternator, starter motor, front sprocket covers are all interchangeable.

The 750 clutch cover will fit too as a temp measure.

Is there really a difference with the starter clutch cover? ( I don't think so )

Posted: Fri Jan 27, 2012 6:14 pm

+ 1 all the covers are the same, 1100 has the clutch mech on the right side of the cover and the gen cover is a different design but they will all fit.

Daz. Very Happy

Posted: Fri Jan 27, 2012 7:13 pm

Thanks, The clutch cover did fit, I did not have a 1100 alternator cover for this bike so I was not so worried about that. It seems like my 1100 bike has a slight angle at the bottom of the ignition timing cover which the 750 lacks (like I will ever be in jeopardy of dragging that part!) Visually everything else looks the same. I will be dropping off the parts on Tuesday so I still have a couple of days. Over the phone the guy said somewhere around $ 150.00 and he wants me to do nothing other than bringing them relatively cleaned (as in grease free.) Doc

CB1100F Joined: May 13, 2005 Posts: 3217 Location: NE OHIO

CowTownBiomed wrote:

Umm...

They are all the same, with minor changes in the outside finishes (fins, ect)
All the valve covers are the same, timing, alternator, starter motor, front sprocket covers are all interchangeable.

The 750 clutch cover will fit too as a temp measure.

Is there really a difference with the starter clutch cover? ( I don't think so )

Yes some of the early and maybe later 750 starter clutch cover have a smaller threaded holes ( 3 ) than the 900 -1100 covers.

Posted: Sat Jan 28, 2012 11:43 am

Ok so now I am second guessing this I went to the Honda micro fiche (www.wnycycle.com then / upper left parts finder then motorcycles) and the part numbers are different. That may just be to the change in numbering over the years from 79 - 83 but I guess I will go to the storage area and swap the ignition and timing cover and as long as I am there I may as well get the sprocket cover from that bike as well. It would really suck to pay for the coating on stuff I can't use! The cam cover looks the same so I will use the 750 one.

Posted: Sat Jan 28, 2012 1:30 pm

Silver vs black is the only reason for the different part numbers on the sprocket and spark advance covers. The ignition cover differences between the models were finned, angled, and plain but all are interchangeable.

Posted: Sat Jan 28, 2012 3:07 pm

Hey Doc, I have 750/900 covers on my 1100 motor.. In fact, I purposely used the 750/900 CLUTCH cover because of the adjustable center locknut. I just replaced the 1100 pusher with a 900 one. No worries at all..

CB1100F Joined: May 13, 2005 Posts: 3217 Location: NE OHIO

cb1100fer wrote:

Silver vs black is the only reason for the different part numbers on the sprocket and spark advance covers. The ignition cover differences between the models were finned, angled, and plain but all are interchangeable.

This is not completely true. Look at the covers for the 79 750F , the screws to hold the ignition cover on are 5mm and the later 750's 900's and 1100 's are 6mm . I am sure if you wanted to you could drill out the screw holes and retapp them, as the centers are the same

Posted: Sat Jan 28, 2012 5:46 pm

Didn't know about the 5mm as I've never seen one and only the 6mm.
After looking it up it seems the 79 750 and the early 80 750's used the 5mm and all the rest were 6mm for all years.

Posted: Sat Jan 28, 2012 10:13 pm

I did not grab the sprocket cover because I didn't feel like screwing with the shifter. I actually am very glad I went back since the motor had the angled / finned 1100 timing cover. The 750 starter gear cover on the left side fit on my 1100 motor without modifications so it must have had the larger holes.

Posted: Sat Feb 04, 2012 3:28 pm

Well our extended fall up here in NNY combined with several other factors has me working towards getting Junior (AKA Sybil) ready to ride. I dropped the parts off at the powder-coater last week and they should be ready soon. SteveG and Cliffec are doing their motors simultaneously which is keeping my "head in the game" or "eye on the ball" or some other pseudo football (Go Giants) reference. Yesterday I moved it to a heated shop so I can finish the carbs and install the parts when they are done.

Posted: Wed Feb 08, 2012 1:08 am

I was going through some parts the other day and it looks like early 750 starter covers were aluminum instead of stamped steel.

Anybody else see this?

Toddk

Posted: Wed Feb 08, 2012 1:31 am

I'm not finding different parts numbers for it.

CB1100F Joined: May 13, 2005 Posts: 3217 Location: NE OHIO

toddk wrote:

I was going through some parts the other day and it looks like early 750 starter covers were aluminum instead of stamped steel.

Anybody else see this?

Toddk

I remember having, seeing one of the aluminum covers but don't remember what bike it was on. Might of been a K C SC or F. I might have to look see if I can find it in the parts bin

Posted: Wed Feb 08, 2012 3:35 am

It looks like maybe the 79 750k LTD had a different numbered starter motor cover, at least from what Service Honda's fiche currently says. It's listed as 31280-425-870 Where the other aluminum colored 750 motors used 31280-425-000.