collapse

www.dimecitycycles.com

https://www.townmoto.com/collections/vanson-leathers


www.restocycle.com

www.CITYLIMITMOTO.com

www.jadusmotorcycleparts.com

www.bisonmotorsports.com

www.speedmotoco.com

www.lostapostlejewelry.com

www.cognitomoto.com

www.sparckmoto.com

www.pistonsociety.com

www.steeltowngarage.com


Author Topic: Re: Scott's 1974 CB360 project- She is alive!!  (Read 55359 times)

Offline stript.714 o/c

  • Posts: 703
  • Monkey see monkey do is all i see now days!
Re: My 1974 CB360 project
« Reply #30 on: Feb 21, 2011, 19:47:01 »
That is a sweet looking bike i cant belive they are so darn expensive :o :o :o

Offline Maritime

  • DTT SUPPORTER
  • *
  • Posts: 9387
Re: My 1974 CB360 project
« Reply #31 on: Feb 23, 2011, 10:47:25 »
Nice build so far, puts my ratty half cafe to shame. If I make it for a ride up to your neck of the woods I will stop by the shop and say hello.  Keep up the great work, paint is very nice.  Oh yeah and the discussion on the oil issue, the head are starved from the factory causing pre-mature wear, some guys drill out the oil channel to help, then add an oil cooler to increase the amount of oil in the bike to help not starve the bottom after.

Cheers,

Maritime
The GL Rebirth: http://www.dotheton.com/forum/index.php?topic=68337.0
CX500 Low budget Bobber : http://www.dotheton.com/forum/index.php?topic=43617.0
"Beer makes you feel the way you ought to feel without beer" -Henry Lawson
"Beer is proof that God loves us and wants us to be happy." - Thomas Jefferson

Offline SpottheDogg

  • Posts: 242
Re: My 1974 CB360 project
« Reply #32 on: Feb 24, 2011, 12:58:54 »
OK, so I took some compression readings but it was hard since the motor is out and I could only get weak kicks after a few I only got 70psi in each cylinder. Is this because of it being cold, out on the floor or my technique or am I missing something. It did run and I don't think it would with 70psi...
I don't have the updated cam chain tensioner or rocker shafts. Is this a major concern?

The cam shaft does have a fair bit of side to side runout, I guess it will need some shims. Overall wear looks minimal

Offline stript.714 o/c

  • Posts: 703
  • Monkey see monkey do is all i see now days!
Re: My 1974 CB360 project
« Reply #33 on: Feb 24, 2011, 17:38:49 »
OK, so I took some compression readings but it was hard since the motor is out and I could only get weak kicks after a few I only got 70psi in each cylinder. Is this because of it being cold, out on the floor or my technique or am I missing something. It did run and I don't think it would with 70psi...
I don't have the updated cam chain tensioner or rocker shafts. Is this a major concern?

The cam shaft does have a fair bit of side to side runout, I guess it will need some shims. Overall wear looks minimal

 Well i dont see you being able to really get a good compression reading if your bike is not in the frame. 70 psi is very low .you want around 180 psi. 150 is your minimum and that is also conciderd low. I recomend since you have your engine out hone it ,get new rings , new gaskets,and ,replace the valves if needed. Keep this in mind if eigther cylinder is 10 t0 15 psi from one another then you need to rebuild your top end. Just some food for thought!!

Offline SpottheDogg

  • Posts: 242
Re: My 1974 CB360 project
« Reply #34 on: Feb 24, 2011, 17:39:36 »
The updated or any cam chain tensioner seems pretty rare, mine really show very little wear and I'm wondering if I can get away with them. I found updated rocker shafts on eBay NOS for cheap.

Offline SpottheDogg

  • Posts: 242
Re: My 1974 CB360 project
« Reply #35 on: Feb 24, 2011, 17:43:53 »

 Well i dont see you being able to really get a good compression reading if your bike is not in the frame. 70 psi is very low .you want around 180 psi. 150 is your minimum and that is also conciderd low. I recomend since you have your engine out hone it ,get new rings , new gaskets,and ,replace the valves if needed. Keep this in mind if eigther cylinder is 10 t0 15 psi from one another then you need to rebuild your top end. Just some food for thought!!


 Thank you, everything looks pretty good in there. I ordered some new rings (stock size) and I already had a complete gasket kit coming. I think the cylinders just need to be de-glazed and I will get the valves seated. What can I do as far as planing the decks? How much can come off?

Offline stript.714 o/c

  • Posts: 703
  • Monkey see monkey do is all i see now days!
Re: My 1974 CB360 project
« Reply #36 on: Feb 24, 2011, 17:52:45 »
  I dont know the answer to this question sorry!!

Offline frogman

  • DTT SUPPORTER
  • *
  • Posts: 1965
  • '74 CB360, '71 CB450, '75 CB550SS
Re: My 1974 CB360 project
« Reply #37 on: Feb 24, 2011, 21:35:01 »
OK as far as checking the compression on an engine that is not PHYSICALLY mounted in something that will let you kick the shit out of the kick start I wouldn't even try to do the test.  Put the sucker back in the frame if you can, and then try to do the test.  Shoot for about 150-160 cold, the sides should be within 10 psi of each other as mentioned. If you get that then I would call it gravy for now.  If not then put about a cap full of oil in the plug holes and give it a min to settle in. Then do the test again  If the pressure jumps up then your rings are prolly shot.  If it crawls up or doesn't change your valves may be leaking. You can hear the valves leak when the compression cycle hits.

IF you think the valves are leaking then do this, go to the store, buy some acetone, pull the head and set the head on its side and pour the stuff into the ports and look at your valves. You should not see any wetness on the combustion side of the valves.  Do the other side. If you see stuff leaking out then your valves are not sealing and you need to figure out why.  I had this issue with my bike and both the exhaust valves some how got bent. The intake valve seats were pretty screwed up too.  I had spares so I pulled the valves out and lapped them all and presto, good seal NO LEAKS.

If your head is good then the next issue is the rings or the cylinders. Get your manual and some measuring devices, feeler gauge and caliper, and get to checking the ring gaps, piston and cylinder wear and such.  The manual will tell you what things should look like although I can say that if you can still see the markings on the tops of the rings you may be close to tolerance on the ring grooves in the pistons, if they are shiny they are prolly shot. I would have ordered the rings after I measured things, I also like ordering the next size up so I can hand file fit each ring to each cylinder.  After deglazing that is. 

The cam should have a shim on the right side, again this is something that the manual will tell you as far as how out it can be without it. You may look around in the engine it might have fallen in if you have the head off. 

There is really nothing wrong with the old tensioners other than you have to be DILIGENT about keeping the effing cam chain TIGHT.  Too mcuh slack will cause the chain to slap the top tensioner mount and tear shit up. It will also chew up the case as well.  KEEP an EYE on eBay, they come by all the time.  The big thing I see with the rocker deal was stronger bolts to hold the head down.  The shafts are pretty much the same size. 

Decking the head is something a machinist will have to go through with you.  There are ways to measure but that is another story.  Find a good reputable guy, tell them what you want and you may have to bring most of the engine to them for measuring, they should tell you what they need. 

Worst part about taking the engine apart is finding shit you don't want to see. MY PO ran the dog piss outa this machine, with a clogged oil filter screen and possibly gas in the oil, for a LONG time.  I found all sorta worn out crap and spent a lot of time measuring things and digging through eBay looking for deals.  I ended up having to do the entire top end and the crank shaft because you can't take the bitch apart and change con rods.

Offline AimSmall

  • Posts: 121
Re: My 1974 CB360 project
« Reply #38 on: Feb 25, 2011, 02:37:24 »
Hey what clip ons are those? Can you give us a link please?

Offline SpottheDogg

  • Posts: 242
Re: My 1974 CB360 project
« Reply #39 on: Feb 25, 2011, 17:09:44 »
Thanks frogman, I canceled the ring order for now. I thought there was only one ring size per piston? If you go up a size in rings go up to oversize piston is what I was told. I have a guy doing the valve seats and measuring the cylinders, they are clean very smooth.

Tarozzi clip ons I bought at www.fastfromthepast.com