CB350 rebuild at home

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yasirsa (yasirsa) 2013-09-10 13:59:46 +0500 #41

abbasi sab pistion sequence is 0 then .25 and 50 75 and last is 100. but using a same piston i might need to change the glass . both pistons are in good shap acutally as before i said the bike was in running condtion and reason due too berings noises timing chain leakages in engine. this is not my taste to run the bike in that condition .after opening engine i came to know to that poor mechanic has adjusted wrong timing between crank and cam and i feel my self lucky that it hasnt damage my engine too much just rollers were bad timing chain cam shaft etc etc were faulty and inshAllah

piston size is approx 66 mm and rings which i am going to use is alto car 1000 cc it has same piston size as mine but after detailed checkup and satisfactory is required.

now going for Kawasaki piston is my last option and they size 68 mm . they are light weight and performance pistons for cb350 but study and technical issues are there.

and your jaggi deserve to import badges parts for her she is beauty and ofcourse if i had her i must do justice her

take care

msabbasi (msabbasi) 2013-09-10 14:50:14 +0500 #42

yasirsa;4042407:

abbasi sab pistion sequence is 0 then .25 and 50 75 and last is 100. but using a same piston i might need to change the glass . both pistons are in good shap acutally as before i said the bike was in running condtion and reason due too berings noises timing chain leakages in engine. this is not my taste to run the bike in that condition .after opening engine i came to know to that poor mechanic has adjusted wrong timing between crank and cam and i feel my self lucky that it hasnt damage my engine too much just rollers were bad timing chain cam shaft etc etc were faulty and inshAllah

piston size is approx 66 mm and rings which i am going to use is alto car 1000 cc it has same piston size as mine but after detailed checkup and satisfactory is required.

now going for Kawasaki piston is my last option and they size 68 mm . they are light weight and performance pistons for cb350 but study and technical issues are there.

and your jaggi deserve to import badges parts for her she is beauty and ofcourse if i had her i must do justice her

take care

I am in agreement with you. I hate to drive a machine that is not 100% good. It is lucky that you opened the engine before more damage could have taken place. This peek inside showed you the handiwork of the previous mechanic (that is why I have done all the work on my project myself).

Lighter pitons do not necessarily mean higher performance. Pistons/con rods/crank assembly is dynamically balanced at the factory. The counter weight is drilled to reduce weight ensuring that the assembly is balanced. If you go for lighter/heavier pistons, you will disturb this dynamic balance and that will result in nasty vibrations. That is what was wrong with my Triumph. Someone had replaced the pistons making it very nasty to ride and I could never get it to run well. If your engine was basically good before you began, then you are 90% there to a successful rebuild. Your plan about the rings is good. Just make sure that the Alto 1000cc car has same size cylinder bore as the CB350 also fix the rings in the pistons and check the ring/grove gap. About 0.002" to 0.003" (0.05 - 0.08mm) should be OK. If the Alto bore is not EXACTLY the came size as your CB350, your engine WILL smoke.

Read this for general interest: cb350 piston/cylinder clearance - page 1 - HELP! 1-800-CAFE-HELP - DO THE TON

Also this hondatwins.net • View topic - Piston ring order, in general

What about the valve guides? bad valve guides/seals will result in a smoking engine too.

Regards

yasirsa (yasirsa) 2013-09-11 08:10:58 +0500 #43

thanks for the web sites . i have studied them and very use full knowledge u share. am taking my engine to check whether they can bore it or not .other wise i would need pindi expert numbers.

Also am buying spray machine

it will also help me to respray my ke70;)

msabbasi (msabbasi) 2013-09-11 13:34:55 +0500 #44

If you are stuck for the pistons, you could consider sleeving your engine. That way your old pistons can be reused and you can control the piston/cylinder clearance to the desired tolerance.

Xulfiqar (Xulfiqar) 2013-09-11 14:16:27 +0500 #45

problem is that installing sleeves in an air cooled engine requires a bit of craftsmanship with dry ice etc. You really need to shrink the sleeves and bake the cylinder to get a solid fusing.

vickytulla (vickytulla) 2013-09-12 03:35:13 +0500 #46

superb suggestion... but sadly not in next century would a lathe machine and cylinder sleevers in Pakistan would understand what you just said ...

yasirsa (yasirsa) 2013-09-13 03:19:13 +0500 #47

thank you xuLfi bhai for clicking idea :). i have started first with crank and i think its not repairable in peshawar.

ovais909 (ovais909) 2013-09-13 03:49:10 +0500 #48

I install bearings like that

yasirsa (yasirsa) 2013-09-13 07:48:35 +0500 #49

What if I just freez sleeves. Will this work

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yasirsa (yasirsa) 2013-09-15 08:12:52 +0500 #50

crank is finaly handed over for repair

yasirsa (yasirsa) 2013-09-16 09:07:12 +0500 #51

and its repaired(H)

msabbasi (msabbasi) 2013-09-16 11:30:16 +0500 #52

This is very good news. Can you share a picture with us? The same shop that did your crank can also have a go with your piston/rings/cylinders etc. In the earlier posts you mentioned that your bike was smoking. Have you found out the cause?

yasirsa (yasirsa) 2013-09-16 14:09:38 +0500 #53

right now crank is laying with him i visit him from my office and cant take it with me to my office (they will be like yar tum job kar rahay hoo ya apnay kam ) anyways he is ready for everything head cylinder valve jobs making teflon rollers making points he said welcome but he is expensive 2 . he satisfied me my every technical question he is educated too . and one of oldest engineer son so he got skills from his father too i will post his pic later

Xulfiqar (Xulfiqar) 2013-09-16 15:09:37 +0500 #54

I had a few machinists freinds in Karachi who would work with me on such items. I also gave them a lot of specialist chemicals like bearing lock, plastigauge strips, FIPG etc - I once explained on what is torque setting and they made a setup with a spring balance pulling on a tommy to make do. Their words were that most customers dont want to pay anything at all for work. They want it free hence they cannot fathom what precision work is.

Xulfiqar (Xulfiqar) 2013-09-16 15:11:05 +0500 #55

Pretty strange office you have there. What does it matter if you have a crankshaft sitting under your desk.

yasirsa (yasirsa) 2013-09-16 15:38:18 +0500 #56

Xulfi Bhai Ke70 with new Honda city engine pls comment

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yasirsa (yasirsa) 2013-09-16 15:41:13 +0500 #57

Xulfi Bhai city vtech engine in Ke70? Possible

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Xulfiqar (Xulfiqar) 2013-09-16 15:58:08 +0500 #58

WHY - why use that piddly scrap metal worth engine when you can fit a very very nice sounding 4AGE blacktop in there.

yasirsa (yasirsa) 2013-09-16 16:08:17 +0500 #59

Bcuz city engine is cheap plus New and economic and compare to k4 it's almost 35 hp plus

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Xulfiqar (Xulfiqar) 2013-09-16 16:14:06 +0500 #60

you forgot one part, its got NO low end torque at all. And the worst part is no transmission bolts to it. The original 4K is not that bad in economy too. Why change it?