Author Topic: Help to analyse compression test results  (Read 9434 times)

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Offline bochnak

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Re: Help to analyse compression test results
« Reply #50 on: February 01, 2016, 06:21:38 am »
I have used Keyster kits several times with no issues. They are the only kit that comes with the emulsion tube, which can wear over time.

Not to hijack, but what were some of the negative experiences with Keyster kits?

Thanks,
Matt

the new Keyster brass stuff seems mismatched and generic which causes poor/too rich,etc. carb. performance

Thanks. Does Keihin still produce the emulsion tube?

Offline _mark

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Re: Help to analyse compression test results
« Reply #51 on: February 01, 2016, 09:35:54 am »
Hi Guys. Good news. Bike is behaving very good ! I run two hours in the last two days and it starts from cold without the need of any spray.


Offline grcamna2

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Re: Help to analyse compression test results
« Reply #52 on: February 01, 2016, 10:45:38 am »
I have used Keyster kits several times with no issues. They are the only kit that comes with the emulsion tube, which can wear over time.

Not to hijack, but what were some of the negative experiences with Keyster kits?

Thanks,
Matt

the new Keyster brass stuff seems mismatched and generic which causes poor/too rich,etc. carb. performance

Thanks. Does Keihin still produce the emulsion tube?

You can check the online parts ordering and see,like motogrid.com
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline flybox1

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Re: Help to analyse compression test results
« Reply #53 on: February 01, 2016, 11:20:10 am »
Hi Guys. Good news. Bike is behaving very good ! I run two hours in the last two days and it starts from cold without the need of any spray.
Great....sooo, what fixed it?
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

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Offline bochnak

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Re: Help to analyse compression test results
« Reply #54 on: February 01, 2016, 11:21:56 am »
I have used Keyster kits several times with no issues. They are the only kit that comes with the emulsion tube, which can wear over time.

Not to hijack, but what were some of the negative experiences with Keyster kits?

Thanks,
Matt

the new Keyster brass stuff seems mismatched and generic which causes poor/too rich,etc. carb. performance

Thanks. Does Keihin still produce the emulsion tube?

You can check the online parts ordering and see,like motogrid.com

Yes, I usually check Honda fiches first. Often times they are not available. I'm not talking about any particular model here either.

Offline flybox1

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Re: Help to analyse compression test results
« Reply #55 on: February 01, 2016, 11:38:28 am »
Emulsion tubes were never sold as an individual part.
Unless yours are severely damaged, yours can and should be reused.
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

Past Bikes
1974 550K0 (stock), 1973 CB350F (stock), 1983 Yamaha XS400K (POS)
77/78 cool 2 member #3
"Knowledge without mileage equals bullsh!t" - Henry Rollins

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Offline bochnak

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Re: Help to analyse compression test results
« Reply #56 on: February 01, 2016, 11:47:25 am »
Emulsion tubes were never sold as an individual part.
Unless yours are severely damaged, yours can and should be reused.

Yes and no, depending on the model. I reuse them if I can. I have seen some worn from the needle, again not speaking to any particular model. In cases like those, I have used Keyster kits w/o any problems because I didn't have any other options. I was just trying to get feedback on Keyster brand from you guys.

Offline flybox1

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Re: Help to analyse compression test results
« Reply #57 on: February 01, 2016, 11:52:43 am »
I learned my lesson tuning my 350F.   Its Keihin only for me, now.
Shouldn't the needle jet prevent any wear on the emulsion tube?
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

Past Bikes
1974 550K0 (stock), 1973 CB350F (stock), 1983 Yamaha XS400K (POS)
77/78 cool 2 member #3
"Knowledge without mileage equals bullsh!t" - Henry Rollins

"This is my CB. There are many like it, but this one is mine…"

Offline bochnak

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Re: Help to analyse compression test results
« Reply #58 on: February 01, 2016, 12:04:44 pm »
I learned my lesson tuning my 350F.   Its Keihin only for me, now.
Shouldn't the needle jet prevent any wear on the emulsion tube?

Here is an image from the web and shows the wear due to needle:


Offline grcamna2

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Re: Help to analyse compression test results
« Reply #59 on: February 01, 2016, 12:28:16 pm »
That piece looks like the needle jet which will come included w/ a new oem needle in the bag;sometimes the emulsion tube has the needle jet attached as one-piece..
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
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Offline grcamna2

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Re: Help to analyse compression test results
« Reply #60 on: February 01, 2016, 12:29:52 pm »
Hi Guys. Good news. Bike is behaving very good ! I run two hours in the last two days and it starts from cold without the need of any spray.
Great....sooo, what fixed it?

_mark,
How did you acheive the smooth running/idling on your bike ?
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline flybox1

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Re: Help to analyse compression test results
« Reply #61 on: February 01, 2016, 12:32:24 pm »
I learned my lesson tuning my 350F.   Its Keihin only for me, now.
Shouldn't the needle jet prevent any wear on the emulsion tube?

Here is an image from the web and shows the wear due to needle:


bochnak....good pic, and ive seen it before.
The needle jet is where the majority of the wear would occur as it centers the needle in the emulsion tube.
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

Past Bikes
1974 550K0 (stock), 1973 CB350F (stock), 1983 Yamaha XS400K (POS)
77/78 cool 2 member #3
"Knowledge without mileage equals bullsh!t" - Henry Rollins

"This is my CB. There are many like it, but this one is mine…"

Offline _mark

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Re: Help to analyse compression test results
« Reply #62 on: February 02, 2016, 08:09:18 am »
Hi Guys. Good news. Bike is behaving very good ! I run two hours in the last two days and it starts from cold without the need of any spray.
Great....sooo, what fixed it?

_mark,
How did you acheive the smooth running/idling on your bike ?

Hi guys thenks and sorry for delay of the aswer but I was busy to run the motorbike.
I simply run for some hours also in motorways and to keep high revs as adviced by my mechanic (make some gym to engine...) and then I tried two mornings to start (5° celsius)  without the help of the fluid and motorbike starts at the second foot kick (I don't use the starting motor to avoid to deplet battery).
Motorbike in my point of view is very good; run ups very fast ... but consider I'm a newbie of motorbikes so my opinion are not so considerable...
Is it normal that minimum RPM is higher in hot conditions (about 200 rpms more) ? I can mantain a setting of 1000 RPMS in hot conditons but when I start from cold I need to hold the throttle.

Thanks.




« Last Edit: February 02, 2016, 08:13:19 am by _mark »

Offline flybox1

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Re: Help to analyse compression test results
« Reply #63 on: February 02, 2016, 08:26:02 am »
Is it normal that minimum RPM is higher in hot conditions (about 200 rpms more) ? I can mantain a setting of 1000 RPMS in hot conditons but when I start from cold I need to hold the throttle.

Thanks.
Yes, this is normal.
Glad its running well
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

Past Bikes
1974 550K0 (stock), 1973 CB350F (stock), 1983 Yamaha XS400K (POS)
77/78 cool 2 member #3
"Knowledge without mileage equals bullsh!t" - Henry Rollins

"This is my CB. There are many like it, but this one is mine…"

Offline grcamna2

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Re: Help to analyse compression test results
« Reply #64 on: February 02, 2016, 09:49:24 am »
_mark,
Would you make a small video of the engine running at idle speed after you come back from your ride ?
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline strynboen

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Re: Help to analyse compression test results
« Reply #65 on: February 02, 2016, 10:01:01 am »
if all are adjustet perfekt..ther first1/3 choke is only give ca 100 rpm..and no real choke..first from half choke it Locks the choke ports..but its only on 77/78 kabel shoke kaburettors...vho have this smart ekstra help.

.on the pre 77 modells,,, handel operated choke,, the gas must be adjusted by trottel turn the handel..
i kan not speak english/but trying!!
http://forums.sohc4.net/index.php?topic=60973.0
http://forums.sohc4.net/index.php?topic=144758.0
i hate all this v-w.... vords

Offline _mark

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Re: Help to analyse compression test results
« Reply #66 on: February 03, 2016, 05:59:33 am »
Is it normal that minimum RPM is higher in hot conditions (about 200 rpms more) ? I can mantain a setting of 1000 RPMS in hot conditons but when I start from cold I need to hold the throttle.

Thanks.
Yes, this is normal.
Glad its running well

sadly in these days is raining. I will post when I can start and run.

Thanks.

Offline jonda500

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Re: Help to analyse compression test results
« Reply #67 on: February 04, 2016, 02:30:03 am »
Mark -  A few comments:
I am not convinced your Mechanic properly cleaned your carbs for 2 reasons: If fully and properly cleaned, the bike would not require a "starting fluid". And, if the carbs are not fully cleaned, it is also possible that the slides are not synchronized and thus, your compression readings will also be negatively effected.

All your reports from riding indicate a poor state of tune and dirty carbs. Get these things done personally or professionally with a guarantee of their results.

There is no benefit to using higher octane fuel in these bikes. The stock compression ratio is about 9.2-9.5:1. This is very well suited to 89 octane. Higher octane fuel only produces benefit with higher compression engines. A fuel additive like "SeaFoam" while beneficial for daily/seasonal treatment of your fuel for Ethanol-based fuels will do virtually nothing for carbs that are not cleaned properly. SeaFoam will not dissolve varnish from fuel evaporation due to prolonged storage.

Compression tests should be performed with the throttle held wide open - as such readings will not be affected by poorly synchronised carbs.
SeaFoam or similar products are exactly what I use to dissolve varnish left from fuel evaporation?
John

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Offline _mark

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Re: Help to analyse compression test results
« Reply #68 on: February 04, 2016, 08:25:45 am »
_mark,
Would you make a small video of the engine running at idle speed after you come back from your ride ?



Offline _mark

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Re: Help to analyse compression test results
« Reply #70 on: February 04, 2016, 08:50:18 am »
now is public  :D

Offline flybox1

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Re: Help to analyse compression test results
« Reply #71 on: February 04, 2016, 08:58:20 am »
sounds great!  I bet you could comfortably drop the idle even more.
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

Past Bikes
1974 550K0 (stock), 1973 CB350F (stock), 1983 Yamaha XS400K (POS)
77/78 cool 2 member #3
"Knowledge without mileage equals bullsh!t" - Henry Rollins

"This is my CB. There are many like it, but this one is mine…"

Offline _mark

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Re: Help to analyse compression test results
« Reply #72 on: February 04, 2016, 09:05:26 am »
Yes, I will   ;)

Offline bochnak

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Re: Help to analyse compression test results
« Reply #73 on: February 04, 2016, 09:22:37 am »
sounds great!  I bet you could comfortably drop the idle even more.

I agree, sounds good. Drop the idle to 1100 or so.

Just sounds like you have to figure a good procedure for starting and warm up. Every bike acts a little different and you'll have to find out what makes it happy  :)

Offline grcamna2

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Re: Help to analyse compression test results
« Reply #74 on: February 04, 2016, 09:40:11 am »
sounds great!  I bet you could comfortably drop the idle even more.

That sounds nice and smooth  :)
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.