72 750 Combat Roadster project

Richard Tool

VIP MEMBER
Joined
Aug 3, 2019
Messages
479
Country flag
Thanks all for the interest and compliments. Now need to sort out Some issues . Idles nicely with air slides (choke ) closed but races when opened . When riding I have to choke it when stopping to lower idle . I have done the bit by yanking one plug lead at a time and opening pilot screws to the point of stumbling but still idles too high when air slides are opened. I will be checking timing with timing light next as I have only static timed it but it seems to me that the static timing has to be very accurate. To be continued...
 

grandpaul

VIP MEMBER
Joined
Jan 15, 2008
Messages
11,077
Country flag
Possibly an air leak at one or the other carb/intake mounting... (or a crack in the balance hose)
 

Richard Tool

VIP MEMBER
Joined
Aug 3, 2019
Messages
479
Country flag
Sounds like your throttle slides are being held partially open...
You may be right FE - I am charging up a battery to power the timing light and I have removed the tank and I am chasing down all in the throttle train . I re routed the throttle cable to the left carb to give it a better lie.
While I had the slide out I made sure that it was bottomed out and tomorrow I will do the same to the right.
 

Richard Tool

VIP MEMBER
Joined
Aug 3, 2019
Messages
479
Country flag
FE gets the prize - throttles were raised . Chased through cables & machined down fitting @ twist grip end to give cable a little more slack . Played with pilot screw & slide screws and I think I have it dialed in now . Waiting on battery to power timing light . Test ride later - will post results and maybe video . Thanks Nigel for the hint !
Cheers - RT
 

Richard Tool

VIP MEMBER
Joined
Aug 3, 2019
Messages
479
Country flag
Carbs all sorted - starts easily, runs strong - idles nice .
Now some gearbox issues . Need to drag clutch to engage first gear - finding neutral easiest by not disengaging clutch and occasional dropping out of fourth gear .
Front brake feels soft - master cylinder has been sleeved down so I know it is supposed to be softer/more travel - a buddy has a vacuum bleeder so I may try that .
All input on these matters welcome - Thanks- RT
 

NPeteN

VIP MEMBER
Joined
Nov 20, 2018
Messages
1,061
Country flag
Here's an idea. If the cam plate is timed too close to the inner cover it can hit the cover and knock itself out of gear (4th back into 3rd) as illustrated by Mr. Hemmings below, perhaps this is causing your gear drop. Not what anyone wants hear after the box is filled with oil, hope this isn't the issue.
Screenshot_20200702-124204.png


My own neutral issues are usually down to a loose clutch cable. Hope this helps.
 

grandpaul

VIP MEMBER
Joined
Jan 15, 2008
Messages
11,077
Country flag
Yet another reason to use an inner cover gasket. No reason the cam should ever come in contact with the case.
 

NPeteN

VIP MEMBER
Joined
Nov 20, 2018
Messages
1,061
Country flag
The quadrant is what impacts the case, caused by incorrect timing of the cam.

Suspect you'd have to mess up REAL bad to have the cam itself hit the case! :oops:
 
Joined
Jun 1, 2003
Messages
1,997
Country flag
If you have a full release on the clutch with NO drag some times you will need to feed it a SMALL aount of clutch to get the first gear dogs to align but the good side is an easy neutral.
 

gortnipper

VIP MEMBER
Joined
Nov 11, 2013
Messages
3,119
Country flag
Try loosening your primary chain a smidge. After I rebuilt my box and put in an IWIS duplex, it was hard to snick it into first and had to drag clutch to do that. Loosening it up 1-2mm of play fixed that.
 

Richard Tool

VIP MEMBER
Joined
Aug 3, 2019
Messages
479
Country flag
Thanks gortnipper - eased off the primary a bit and it indeed helped matters - I’m going to leave it there for a bit and see if running in improves things . Finding neutral much better as well
 

Richard Tool

VIP MEMBER
Joined
Aug 3, 2019
Messages
479
Country flag
Thanks Steve - looking forward to see your project progress.

Somewhat afraid to put this in print for fear of what may turn around and bite but I’ve put about 50 miles on it and got it away from our seaside resort town to reach 60 mph . Running, shifting and braking beautifully. Starting on one kick , nice idle. Foot brake pedal sagging a bit now and then so brake light stays on . I’ve bought a new spring in hopes that it will cure this . That pedal really should have it’s own spring rather than rely on the brake arm - something to explore.
I don’t want to wish my life away - I’ll be turning 67 in a little more than a week - but I can’t wait till it is run in and the summertime madness is over . I want to move past 4K on the tach in some cold , dry dense air and hear that beautiful Norton high pitch growl again.
It’s coming soon enough I suppose.
Cheers - RT
 

Craig

VIP MEMBER
Joined
Dec 20, 2005
Messages
2,331
Country flag
There is a rear brake safety coil/spring that will hold your rear brake lever exactly where it should be at rest , even if your cable breaks , considered a helpful safety device , you don’t want to be rolling if cable lets go and lever digs in , you can end up on the ground ..... just a great bike RT !
 

Richard Tool

VIP MEMBER
Joined
Aug 3, 2019
Messages
479
Country flag
There is a rear brake safety coil/spring that will hold your rear brake lever exactly where it should be at rest , even if your cable breaks , considered a helpful safety device , you don’t want to be rolling if cable lets go and lever digs in , you can end up on the ground ..... just a great bike RT !
Thanks Craig - where do I find one - Andover , etc ?
 

Top