[cafecbn]

When I drop it down to 1st the gear goes in pretty harsh.... And it is not really responding coming out of first gear either. I ve tried to do clutch adjustments, but the clutch lever is still very loose. Once you get it going she goes through the gears fine, but pulling on to traffic with no response is pretty sketchy. I opened the clutch up and measured both pressure and friction plates and found that 2 of the friction plates, and 4 of the pressure plates were warped (Reffering to Manual specs). Will my problems go away once I get a new clutch kit? or should I also change the clutch cable?



Edited by - cafecbn on Jan 21 2007 11:28:11 AM

 

[cafecbn]

Its a 1974 CB 750.... Thanks in advanced.

 

[kenessex]

Change the cable and the plates. lube up the old cable and keep it for a spare(you'll need it sooner or later). Also replace the clutch springs and check the outer clutch basket for grooves where the tabs on the fiber plates hit and the inner clutch basket where the fingers on the steel plates bear. Grooves or notches in either of those places will cause issues, too.
Ken

AHRMA 412
Vintage racing - old guys on old bikes

 

[joe c]

yeah, if you have notches in your basket notches, the plates will hang and do really weird things at intermittent times. so check that too. springs, probably not in my opinion. warped plates i dont think would cause your problems either, but fix them none the less. although if they are warped i guess they could be hanging up. keep us posted.

jc

 

[cafecbn]

Thanks for the info, How do you check the basket? is it something visible, because from looking at it... all is well. But then again I may be missing something.

 

[joe c]

the basket has those tangs that kind of stick up. the clutch plates slide into them and stay aligned on the outside of the plate. those tangs should be smooth, top to bottom. no notchiness.

j

 

[cafecbn]

I found notches on some places along the basket, can I get away with it by fileing them down to smooth? or will it mess up the integrity of the teeth... some are visible marks from time, and others you can actually feel the groves...

 

[joe c]

i guess you could try and file them. i doubt it would hurt the basket but it might make noise in the clutch if there is too much play. i saw this same thing on the rs125 clutch basket and it was definitely causing a hang problem. it actually wasnt letting the bike into gear all of the way because it was hanging up.

guess it cant hurt to try eh?


j

 

[cafecbn]

I just spoke to a tech over the phone, and he mentioned that the problem may be from the Shift drum or Shift shaft?? He stated that if that was the case it would be a shit load of work and engine would have to be pulled out? I am hoping for the best after I change the friction and pressure plates, fuck I am a bit worried.

 

[imslow]

a tech over the phone? Was he (she) from India?

 

[cafecbn]

Funny... It was some local guy in FL giving his two cents.

 

[Geeto67]

most of the basses have already been covered but I'm just going to add this in:

Since you have to replace your warped plates, go with stock honda steels and fibers (replace all of them) and replace the springs with barnett springs. This is the best clutch setup for a street cb as the barnett plates will be too hard and the stock springs are too soft.

with cb750s it is better to replace than file down to work, the parts are cheap enough and it isn't a hard job.

 

[fuzzybutt]

speaking of cb clutches, lol. is there a better quality clutch plate available for the sohc 750's? just synoed mine this afternoon and the 95hp at the wheels just CANT be a good thing on stock friction materials with super heavy duty springs. i know theyre gonna let go before i have 1000 miles on the new motor.

some people are like slinkies, basically useless but they still make me smile when i push them down the stairs

 

[Geeto67]

quote:
speaking of cb clutches, lol. is there a better quality clutch plate available for the sohc 750's? just synoed mine this afternoon and the 95hp at the wheels just CANT be a good thing on stock friction materials with super heavy duty springs. i know theyre gonna let go before i have 1000 miles on the new motor.

some people are like slinkies, basically useless but they still make me smile when i push them down the stairs

barnett makes a heavy duty clutch for the SOHC but the lever feel is way too heavy for the street (plates and fibers are thicker and in some instances there is one more plate and fiber than stock). The stock clutch will probably spin itself to death with 95rwhp. A few guys I know with hot rodded motors (including myself) run the stock steels and fibers but with the heavy duty barnett springs, since it is the spring clamping force that helps hold it together once engaged.

I just have to ask - how are you getting 95rwhp out of a cb750 SOHC? Considering most make between 53 and 58 rwhp 95hp is no small feat. Most guys with 836 kits don't come close to that without porting, pipes, and carbs. MReik on the SOHC board makes more with his "million dollar cb" but not by much and he is a tuning master and that bike uses every trick in the book.

 

[fuzzybutt]

11:1 compression (bastard to kick start) 890cc's with a late model 750f cylinders and cases, forged rods, fgrind harmon cam, ported/flowbenched 750f head, 32mm mikunis from sudco, dyna ignition and coils and a new supertrapp header and kerker silencer as well as aluminum sprockets

some people are like slinkies, basically useless but they still make me smile when i push them down the stairs

 

[joe c]

and no pic. loser!

jc

 

[Geeto67]

quote:
11:1 compression (bastard to kick start) 890cc's with a late model 750f cylinders and cases, forged rods, fgrind harmon cam, ported/flowbenched 750f head, 32mm mikunis from sudco, dyna ignition and coils and a new supertrapp header and kerker silencer as well as aluminum sprockets

some people are like slinkies, basically useless but they still make me smile when i push them down the stairs

where did you get the 890cc pistons from? are they forged? must have been a pretty penny. Most of the performance stuff in the market is geared toward the K stuff, using the F head is unique and personally I think the right way to go.

 

[fuzzybutt]

got em on e-bay cheap only 350 bucks. the downside is the bike isnt as streetable as it was with the stock compression 810cc motor i built earlier this year. i may end up taking the 890 out and putting it into an amen savior frame i have and selling it. this time of year this high compression motor isnt so bad but i imagine with the beastly hot summers we have here with heat index at 110 or so i'll be regretting it. and yes they are forged with total seal rings. big ass studs on the barrells too.

some people are like slinkies, basically useless but they still make me smile when i push them down the stairs

Edited by - fuzzybutt on Jan 31 2007 4:25:30 PM