I forgot about that and your right, the cams can be in the wrong place and wouldn't show in your photos. Good thing you pulled the cap and checked.

With proper cam timing the marks can be 180 out but how do you time them in the first place? Why install them upside down as if you are timing the cams to #4 when you can simply time them to #1 by rotating them up. You can rotate the crank twice to bring the marks up but its best to do it correctly as follows.

1-With cams out so that you don't risk bending valve stems, bring #1 (and #4) piston up to TDC and check crank timing mark .

2-Install cams and check cam lobes on both cams (if sprocket is installed correctly, valves will be closed for both IN and EX cams on #1). If not rotate cam to get makes in step 3a and 3b. You may have to rotate sprocket 180 for that cam.

3a-The "EX" mark on the exhaust cam will be flush with the flat surface of the front of head.

3b-The "IN" mark on the inlet cam will be flush with the flat surface of the rear of the head.

Its best to get the cam chain and EX cam installed and then install the IN cam. The IN cam gets one tooth off easy and you will have to look closely at it.

 

I will bring this thread to conclusion as soon as my friend is on the mend and makes it out here to assist in redoing the cams. He was knocked off his bike this afternoon by a blind cager. He is hoping to be able to assist by Tuesday. I'd do it on my own but do not possess a torque wrench which is critical to this job. Thoughts are with you my friend, hope no broken bones etc. unless they belong to the blind cager who did this terrible thing.

 

My Goodness!

Sorry to hear that David.

I hope your friend is ok and heals rapidly.

And well done with solving the conundrum.

SB

 

And there we are, 1 x running CBR. Amazing what happens when you put the cams in the right slots. Sadly she sounds rough as a bears backside. Think no2 isn't firing at all. Still not bad for a nights work. Thanks to one of my customers who lent me his torque wrench. Now at least my broken friend can relax tomorrow and heal up properly while I figure out why I have a 3 cylinder CBR 750 Probably something small, but I'm off to bed now. Will check tomorrow

 

Tonight she sounds sweet. Seems the carbs are still the problem. I put the SC21 bank on and perfect. Trouble is they don't have a vacuum take off for the fuel tap. Going to have to either sort out the SC24 set (which has already had the benefit of a full tin of carb cleaner and a major blasting with a 8 bar compressor) or find a way to run the SC21 carbs. I'm thinking one of the vacuum ports on top of the carbs used for balancing should have enough vacuum to keep the tap open. Don't know if anyone has tried this before? Otherwise I must keep battling with the clogged 21 carbs till they come right. But not tonight. Heard her sounding good and that's it, going to get warm and relax. Advice welcome...

 

I'm thinking one of the vacuum ports on top of the carbs used for balancing should have enough vacuum to keep the tap open.


You got it - it'd work just fine

 

Thanks, for now I will just use the carbs that work, need to put some miles on this bike. Should be a simple case of putting on an airbox, tidy up the wiring and blank off the water pump bleed hose. Bolt on some bodywork and should be able to get on the road for a bit this weekend She still backfires a bit under acceleration in neutral which I guess is because she has no airbox at the moment

 

Good luck with the ride on the weekend David, it has been a bit of a saga and I hope you are rewarded with a good solid fun run on the weekend.

Post some pictures of your ride.

Cheers, SB

 

+ 1 David have a great trip man - post a pic of her on her travels ?