Author Topic: Is my Transmisson worn or out of adjustment (Read 2882 times)

tsransom · « **on:** July 29, 2006, 06:53:38 PM »

Hello All,

I just rode my new bike, a 1974 CB750. The only other bike I have ridden is my 1981 CB650. The CB750 transmission seams much harder to shift and neutral is very difficult to find from first gear, sometimes as I am shifting from 1st to 2nd while riding, it will go into neutral insted of 2nd(more frequent under harder acceleration). I have replaced the clutch cable and adjusted the mechanism as per the clymer manual. The clutch doesn't drag. Is ther a shift mechanism ajustment or is my gearbox badly worn? the Bike has 40,000miles on the clock.

750goes · « **Reply #1 on:** July 29, 2006, 10:18:43 PM »

I do not think there is any shifter adjustment, it could just be you getting used to the shift of the older bike.. also depending on the previous history and use/abuse of the bike, it could quite easily have worn selectors, accounting for the sometimes hard/sloppy movement in between or through gear selection.

johnny-from-bel · « **Reply #2 on:** July 30, 2006, 08:44:50 AM »

The 750 gear is hard to shift. I you do not shift correctly you will end up in what is called a false neutral. That is the position in between to gears.

So far what you experience seems normal to me. Wear ususlay shows by slipping out of gear.

supersport_CB400F · « **Reply #3 on:** July 30, 2006, 02:02:41 PM »

Change the oil and adjust the clutch again, not just the cable.

eldar · « **Reply #4 on:** July 31, 2006, 07:09:16 AM »

these clutches are pretty hard to screw up unless you actually try I think. Do the bifta thing, change oil but make sure there is no moly or energy conserving additives in it. Make sure the clutch is adjusted right too. It may be not be opening far enough to allow proper shifting.
I know my 750 shifts better than some new bikes today do. One thing you will find though, getting into neutral is a bit tough sometimes when you are not moving. So just roll either forward or back while going to neutral and it will barely take any movement, maybe an inch. or go into neutral before you stop.

tsransom · « **Reply #5 on:** July 31, 2006, 11:51:59 AM »

Thanks for the Information. I just changed the oil, I used 30W engine oil(not motorcycle specific) is this the incorrect oil? I will adjust the clucth mechanism(back off 1/4 turn after resistace is felt) and adjust the cable for freeplay.

Bob Wessner · « **Reply #6 on:** July 31, 2006, 12:04:46 PM »

You don't mean straight thirty weight do you? That would be too thick for a cold start and too thin for when hot, or do you mean 10w/30? Either way, 30 weight is a bit light.

supersport_CB400F · « **Reply #7 on:** July 31, 2006, 12:10:09 PM »

Wouldn't be my choice of oil

I use 10/40W but I am in the UK and the temp is lower than some places in the world usually.

ProTeal55 · « **Reply #8 on:** July 31, 2006, 01:03:15 PM »

You just need to slam that trans. into gear.
Mine has been a #$%* since the day I got the thing.
Just the nature of the beast, and a 30+ year old bike...

GroovieGhoulie · « **Reply #9 on:** July 31, 2006, 01:28:13 PM »

I live where it's hotter than hell, so I am trying out 20w50 right now. Seems to help clutch engagement because sometimes with 10w40, the clutch would slip as it engaged when tearing around.

Might try 10w40 again as it gets cooler.

ProTeal55 · « **Reply #10 on:** July 31, 2006, 01:29:38 PM »

I am a huge fan/believer in 20w50...

GroovieGhoulie · « **Reply #11 on:** July 31, 2006, 01:31:39 PM »

Quote from: ProTeal55 on July 31, 2006, 01:29:38 PM

I am a huge fan/believer in 20w50...

The rub is it robs about 1 HP (according to Hondaman) and the little 400 needs all the help it can get, so I tihnk I'll switch back to 10w40 at the next change.

tsransom · « **Reply #12 on:** July 31, 2006, 02:37:56 PM »

Well, I'll warm it up and drain the oil tonite. Is 10W40 Motorcycle oil OK to use? Lately it has been 20-30C C(68F-86F)Outside.

eldar · « **Reply #13 on:** July 31, 2006, 03:45:01 PM »

I have used 10-30 oil before and never had an issue. It is all in how hard you ride and how often you get stuck in traffic. 10-30 is fine if you do not ride like nuts or get stuck in traffic for long periods of time when it is hot. however, you want to stay away from oils that have moly or say "energy conserving".

10-40 is fine, it is even in the manual. Dont waste your money on motorcycle specific oil though, there is nothing special about it. Just get a quality oil such as mobil-1. I have used Havoline also and it worked ok. Castrol is also good stuff, almost as good as mobil-1 and cheaper.

diamondd · « **Reply #14 on:** July 31, 2006, 04:41:27 PM »

I to am a firm believer in 20w50. And I started using Castrol gtx. Real please with that move.

johnny-from-bel · « **Reply #15 on:** August 03, 2006, 02:55:18 PM »

Quote from: tsransom on July 31, 2006, 02:37:56 PM

Well, I'll warm it up and drain the oil tonite. Is 10W40 Motorcycle oil OK to use? Lately it has been 20-30C C(68F-86F)Outside.

For normal use at temps around 25C, 10W40 or 20W50 does not make a big difference. Don't use any syntectic or oil with friction enhancers. The wet clutched don't like that.

eldar · « **Reply #16 on:** August 03, 2006, 03:54:58 PM »

Synthetics are absolutely fine. It is oils that contain moly or energy conserving additives.

Honda makes synthetic that works fine in our bikes and some here use it.
Please do not keep to that misconception.

johnny-from-bel · « **Reply #17 on:** August 04, 2006, 10:17:55 AM »

Quote from: eldar, Master of the K8 Thunder! on August 03, 2006, 03:54:58 PM

Synthetics are absolutely fine. It is oils that contain moly or energy conserving additives.

Honda makes synthetic that works fine in our bikes and some here use it.
Please do not keep to that misconception.

Hmm..., did not know that. What Honda oil is that ?

superchode · « **Reply #18 on:** August 04, 2006, 11:44:53 AM »

there's plenty of motorcycle-specific synthetic oils around. designed for wet clutches.

i use amsoil's 10W-40 synthetic motorcycle oil in my VFR and it's in the 750 as well - although that's a couple of weeks away from being in regular use.

eldar · « **Reply #19 on:** August 04, 2006, 11:59:49 AM »

Well I think the honda hp-4 might be synthetic. I know honda DOES have synthetics thats are just fine.

nteek754 · « **Reply #20 on:** August 04, 2006, 02:47:37 PM »

dump that oil and adjust the clutch HMMMMM nature of the beast I dont believe that for nuttin got four of them in my garage the newest is a 77 750 and all of them shift great like someone else said usually worn out trannys slip out of gear now not to say the P O didnt abuse it but do whats right first then lets see good luck seven fifty four ever Craig in Maine

johnny-from-bel · « **Reply #21 on:** August 05, 2006, 05:34:12 AM »

Quote from: eldar, Master of the K8 Thunder! on August 04, 2006, 11:59:49 AM

Well I think the honda hp-4 might be synthetic. I know honda DOES have synthetics thats are just fine.

So, witch one do you use.

eldar · « **Reply #22 on:** August 06, 2006, 09:50:20 AM »

I have not actually used synthetic in mine. If I do though, it will probably be mobil-1 synthetic. Currently I use rotella t 20-50 but will probably change that out soon as in a month or so, the temp is going to start sropping here to where 20-50 will flow too slow and actually cause engine damage cause of that. Will probably drop to 10-30 maybe 10-40.

Next year I will probably do synthetic though. I NEVER buy motorcycle specific oil. Why waste my money when auto oil is just as good and cheaper.

http://www.xs11.com/stories/mcnoil94.htm

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Author Topic: Is my Transmisson worn or out of adjustment (Read 2882 times)

tsransom

johnny-from-bel

supersport_CB400F

eldar

tsransom

supersport_CB400F

tsransom

eldar

johnny-from-bel

eldar

johnny-from-bel

eldar

johnny-from-bel

eldar