CB350 Built by a teen (Weld Now, Grind Later)

Re: CB350 Built by a teen (Millin' and billdin')

haplo_84 said:
lol, I'm super happy to see you making progress man. Been following since like around page 70. This is like a timeline measurement for me. :D
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me too. I kind of wish i was spending less time in Malta (leaving tuesday for a month) so that I could get the bike done.
 
Re: CB350 Built by a teen (Millin' and billdin')

Hey, you know what man, your doing alot more than i could ever do at your age. I wish i could even get anything done on mine. I work at night and my neighbors in the apt complex already got pissy with me for working on it at night when i had days off. I had to kinda put it aside and put in more planning for later.
 
Re: CB350 Built by a teen (Millin' and billdin')

surffly is popping by with a spare parts motor that i can mess around with at a later date, also going to double check that I totally didnt screw up my cam install.

thanks to vonyinzer I'll be coming back to some kick ass finned points covers! my search of two years is over =D
 
Re: CB350 Built by a teen (Millin' and billdin')

thanks to surffly for stopping by...

will have to spend some time getting the timing right with the motor. I had noticed that the tension on the ka tensioner goes from tight to loose and tight again as if the chain wheels are out of round. neither me, will, or his friend could figure it out. guess ill be pulling shit apart again unless if someone has an idea.

sigh; total pain in the ass. least I have a spare parts motor if worst comes to worse.
 
Re: CB350 Built by a teen (F***** problems, yay)

Either cam is bent (unlikely) or sprocket isn't fitted properly.
You did check cam for run-out?
 
Re: CB350 Built by a teen (F***** problems, yay)

crazypj said:
Either cam is bent (unlikely) or sprocket isn't fitted properly.
You did check cam for run-out?
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i did by eyeing it, but I'll check again. sprocket not fitted properly is a possibility as I hadn't tightened down the bolts on it completely? either way, the amount the tension seems to vary is quite large.... maybe its enough for there to be an issue? least I have a spare cam.... the cam I have in there now has minor pitting on one of the lobes anyway; I figure I might as well install the nicer one.


PJ... quick question on setting valve timing. The way I'm going to do it is to find TDC (I was using the pencil in bore method to find the high point, check on degree wheel, keep turning till it goes down, divide two degrees, set that point as TDC yada yada) then attach my degree wheel to the rotor with that point as TDC, make a pointer attached to motor to see where I'm at easily, turn motor to 10* BTDC on the left piston intake stroke, and use my dial caliper hooked up to a stand to set the intake lobe on the cam to JUST start opening at 10* BTDC (10* BTDC is spec I found online for stock cam... if you have a number that performs a little better I'm open to using that... I'm thinking 8* BTDC to make up for minor chain stretch/valve lash?).

anyway. it will all wait till I get back
 
Re: CB350 Built by a teen (F***** problems, yay)

Keep in mind that when valves are being opened, the crank pulls the cam,
while being closed it's other way round, know what I mean?
 
Re: CB350 Built by a teen (F***** problems, yay)

scm said:
Keep in mind that when valves are being opened, the crank pulls the cam,
while being closed it's other way round, know what I mean?
Click to expand...

yes, got you...


anyway, back from my very nice vacation. while there I bought myself a mini to leave there. no, not the bmw monstrosities... a 1972 (same year as bike!) austin mini 1000, with a metro motor and body kit. new interior and in very clean condition, for 1100 euro =D. next summer I'll do more work to that thing, but for now I'll just forget about it and work on my bike.

so, checked the camshaft for any runout, and theres none at all. its all straight and good. so thats bad luck, as that means its either bent crank (dont see HOW though...) or possibly the cam wheel wasnt manufactured properly. I'll try fitting the stock one and see if that gets rid of the issue.

got less then two weeks before i go off to college, so trying to get as much done as I can before then.
 
Re: CB350 Built by a teen (F***** problems, yay)

Rocan said:
i did by eyeing it, but I'll check again. sprocket not fitted properly is a possibility as I hadn't tightened down the bolts on it completely? either way, the amount the tension seems to vary is quite large.... maybe its enough for there to be an issue? least I have a spare cam.... the cam I have in there now has minor pitting on one of the lobes anyway; I figure I might as well install the nicer one.


PJ... quick question on setting valve timing. The way I'm going to do it is to find TDC (I was using the pencil in bore method to find the high point, check on degree wheel, keep turning till it goes down, divide two degrees, set that point as TDC yada yada) then attach my degree wheel to the rotor with that point as TDC, make a pointer attached to motor to see where I'm at easily, turn motor to 10* BTDC on the left piston intake stroke, and use my dial caliper hooked up to a stand to set the intake lobe on the cam to JUST start opening at 10* BTDC (10* BTDC is spec I found online for stock cam... if you have a number that performs a little better I'm open to using that... I'm thinking 8* BTDC to make up for minor chain stretch/valve lash?).

anyway. it will all wait till I get back
Click to expand...

Hi Slacker ;D
Where's pics of topless tarts? ;)

Pretty sure cam won't be bent, you have something assembled wrong.
It is a new cam chain?
did you wash it out and re-oil? Could be tight spot from grease in rollers

You need a positive stop. , pencil in plug hole can vary be 10 degrees or more.
Get an old plug, break out the center (grind the swaged area off) Tap 8x1.25 and thread in a rod with rounded end.
Put piston just BEFORE where you think TDC is, fit degree wheel to crank and fit pointer.
Rotate crank 360 degrees, you'll have to go backwards (if sprocket isn't bolted up there is no chance of valves hitting stop)
Real TDC is half way between points.
I usually fit degree wheel with head off, still use a positive stop though. (as pics in my 360 'novel' ;D )
 
Re: CB350 Built by a teen (F***** problems, yay)

Honda specs for cams is at 1.0mm IIRC, so the cam should have lifted the valve 1.0mm at that 10 degree point.

Almost impossible to bend a crank. Cam is possible but not common. Most likely it's a tight spot in the chain as PJ mentioned of something odd about that cam sprocket.
 
Re: CB350 Built by a teen (F***** problems, yay)

hmm, so tight spot in crank would simply go away after being run in a bit. I'll check the cam sprocket for being out of round, but doubt it as its a machined piece. though possible that the sprocket was machined in a way that caused some of the teeth to be deeper then the others? hmm... will figure it out. chain wasnt washed then re-oiled... live and learn.

that method makes a ton of sense for finding tdc... thanks pj.

teazer... 1.0mm at 10* BTDC correct? hmmm.. how the hell am i supposed to measure valve lift with the head together? My understanding was that the cam should just begin to open the valve at 10*btdc (way i would find it would be to fit dial caliper to cam lobe, and at 10* BTDC the dial caliper should just begin to lift).

unless if someone knows how many mm of lift on the cam lobe corresponds to valve lift? or in other words the rocker arm ratio (assuming unworn rocker arms and zero lash?)
 
Re: CB350 Built by a teen (F***** problems, yay)

You take tappet cover off and use DTI on spring retainer, go look at the pics of my 360.
http://www.dotheton.com/forum/index.php?topic=11736.125
You will need an extension in DTI, but, working in a cycle shop you should be able to find a spoke that threads into DTI (they are either 2.5mm or 4x '40 something' thread, I forget exactly, probably 48tpi?)
Just unscrew the ball end tip on DTI
 
Re: CB350 Built by a teen (F***** problems, yay)

I can rarely find the right extension for my DTI (dial test indicator aka dial gauge) and have been known to modify almost anything, including a spare carb needle to do duty as an exension. They are typically around 2.5mm diameter at the root.

Yes. the valve should be lifted 1.0mm by 10 degrees and so on. It takes a bit of time to set up teh DTI and make up a bracket. It doesn't have to be hugely solid, but if it flexes much the answers will all be wrong.
 
Re: CB350 Built by a teen (F***** problems, yay)

very helpful stuff... only problem im running into now is finding a way to hold crank in place as i tighten the degree wheel on, and then being able to move the crank without knocking degree wheel out of place. >,>

I feel like giving up and fitting stock sprocket for now then changing it later when i get a hotter grind on my cam
 
Re: CB350 Built by a teen (F***** problems, yay)

water? what water.... the beer is cheaper then a soft drink at most places! not to mention im legal there xD

anyway... realized that the bore-tech sprockets inside diameter was larger then that of the cam, causing it to only be resting on the bolts (and hence, the tight spots) got fed up with it and installed the stock cam, and low and behold, no tight spots, and its actually easy to line up timing marks ;)

set valve clearance, everything spins without issue and no valves hitting pistons, so i think i actually did something right!

started on electronic ignition install
 
Re: CB350 Built by a teen (F***** problems, yay)

timing set! engine is "done" (besides for adjustment and hooking up carbs/exhaust). need to make an ignition only wiring harness to test run the engine. sweet.
 
Re: CB350 Built by a teen (F***** problems, yay)

Rocan said:
timing set! engine is "done" (besides for adjustment and hooking up carbs/exhaust). need to make an ignition only wiring harness to test run the engine. sweet.
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Not that hard. :b
Keep it up bud the hard work is done..
 
Re: CB350 Built by a teen (F***** problems, yay)

Weh hey! Buffy is back !
Did you have a good time living it large in the Med?
Do we get to see your Mini then.
:)
 
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