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Author Topic: 836 big bore and oil leaks.  (Read 6994 times)

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Offline cben750f0

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Re: 836 big bore and oil leaks.
« Reply #25 on: May 14, 2005, 09:01:12 PM »
na, it was a funny thing, i went with a bloke to get his bike dyno tuned... you know power commander,aircleaner, pipe job... while i was there the owner of the dyno shop asked if i wanted to put it up...there is a vid of it on the dyno, in the move part of this forum... i said no initially... but he talked me into it... as it was i wouldnt have been able to put it on the dyno anyway, the motor was really sick wheni got the bike... and went straight to the bigbore kit... sorry no numbers..peace
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Offline Sam Green Racing

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Re: 836 big bore and oil leaks.
« Reply #26 on: May 14, 2005, 09:21:19 PM »
OK guys. thanks for the company, it's almost 5.30am in the UK and time to go home and bed. (night worker)

Hope motodave has run his bike by the time I am back on tonight. Fingers crossed for him.

See yall   Sam.
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Offline Sam Green Racing

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Re: 836 big bore and oil leaks.
« Reply #27 on: May 15, 2005, 02:49:32 PM »
Motodave,

How'd it go, no smoke I hope. 
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MotoDave

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Re: 836 big bore and oil leaks.
« Reply #28 on: May 15, 2005, 05:00:13 PM »
After some minor smoking after firing it the first time, it seems nice and tight.  However, the carb/ignition gremlins that the bike had before have returned.  The engine still has a tendency to misfire under high load/RPM.  I can tell she's got more snot, but I have yet to unrelease the power!  My bike's a K0, so I've got a set of later model K1-K6 carbs to make tuning easier, but they aren't ready yet, so I installed the originals.  I'm thinking now perhaps It's an ignition issue.  I've got new points/condensors with CB900 coils and new wires on it now, but the electronic conversion is looking tasty...
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Offline Sam Green Racing

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Re: 836 big bore and oil leaks.
« Reply #29 on: May 15, 2005, 05:18:18 PM »
Dave,  Go electronic and a cooler set of plugs, its well worth doing if the climate is hot where you are.
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Offline MRieck

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Re: 836 big bore and oil leaks.
« Reply #30 on: May 15, 2005, 06:15:53 PM »
You need an electronic ignition. I have seen 836's go from 60 to82 HP(and a little higher) DEPENDING ON MANY VARIABLES. Carb size,cam, port work. valve size, ignition, pipe, compression, deck height etc, etc. CR31's are big for that displacement- I think 29's are better. With CR's you should be in the 73 to 75 HP range (at least) with average good, smart tuning choices. Start running oversize valves with .400lift cam/port work and a Dyna 2000 with good compression and you'll see good #'s.
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MotoDave

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836 big bore and Performance
« Reply #31 on: May 16, 2005, 06:58:57 AM »
In addition to the 836 kit, she's got new Ampco 45 Bronze valve guides and oversized Kibblewhite Black Diamnond valves :D.  So the motor should be wicked tight now. Otherwise it's got stock carbs with pod filters and a 4 to 1 exhaust.
What does everyone think of the Boyer Bransden electronic ignition?  It relpaces the mechanical advancer and would seem to be a step above the Dyna ignition.
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Offline MRieck

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Re: 836 big bore and oil leaks.
« Reply #32 on: May 16, 2005, 08:02:26 AM »
I have never used the Boyer. The Dyna 2000 is digital with 5 different advance curves- I don't know if the Boyer offers that. The Dyna also has built in static timing which makes set up a breeze.
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Re: 836 big bore and oil leaks.
« Reply #33 on: May 16, 2005, 08:45:17 AM »
Ah, a Dyna 2000 is a step up from the Dyna S, correct?  The Dyna S uses the stock mechanical advancer, so I suppose the 2000 doesn't.  What kinda coin are we talkin'?
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Offline MRieck

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Re: 836 big bore and oil leaks.
« Reply #34 on: May 16, 2005, 09:16:48 AM »
Yes, it's a whole different animal from the "S". They list for about 400.00 though I'm sure you can get them cheaper. I would try "Dynoman". Dyna was out of the CB750 units for a long time and recently made up about 50 units. I sent one to a guy in Finland about 3 months ago. They are great units- I have one on my FJ1200 too which is 1314CC with alot of engine mods and nitrous. I have installed these units on over a dozen different bikes with excellent results. I thought a module had crapped the bed on one and called Dyna. I sent it to them for a diagnostic check up ( it checked out OK) which was free including return postage. Good stuff- not cheap but you get what you pay for (most of the time ::) ).
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Re: 836 big bore and oil leaks.
« Reply #35 on: May 16, 2005, 10:44:30 AM »
Wow, the Dyna 2000 kit looks awesome.  However, I'm not 100% sure that my misfiring under high load/RPM is ignition related.  I synced the carbs and it still misfires just like it used to.  I like the idea of having a rev limiter, I over-revved once last year and the adjusting nut/set screw on one of the rockers came loose!
Do our bikes need copper cored ignition wires?  I just put a set of 7mm wires on from the auto parts store...
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Offline MRieck

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Re: 836 big bore and oil leaks.
« Reply #36 on: May 16, 2005, 10:55:11 AM »
Copper wires are fine with Dyna S or points. Dyna 2000 requires spiral core or suppresion wires. Coils with alot of Ohms can cause misfire at high rpm because they cannot saturate quick enough BUT that's at pretty high RPM. Point bounce can cause alot of misfire at high Rpm also. Generally even if the carbs are out of synch it doesn't effect the engine at WOT- the slides are fully open. The rev limiter IS nice- take my word for it. :'(
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Re: 836 big bore and oil leaks.
« Reply #37 on: May 16, 2005, 07:57:19 PM »
Before I dump more money into an ignition system, I'm going to try and determine if I have an ignition problem.  I'm running Champion 810's and they seem to read OK, but the manufacturing on these plugs suck.  although they all have the same protruding length, some actually have longer insulators than others.  It's obvious with the naked eye.  While I had the plugs out I did a cold compression test and got 200,200,205,210 psi in cylinders 1-4.  A far cry from the 160-165 numbers I got before the 836 kit and valves. In any case, I'm going to put different plugs in just in case (the 810's were new.) Any diagnostic suggestions?
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Offline kghost

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Re: 836 big bore and oil leaks.
« Reply #38 on: May 16, 2005, 08:01:02 PM »
I wonder if the blow by is caused by the pistons being straight out of the cb350 twin kit?
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Offline MRieck

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Re: 836 big bore and oil leaks.
« Reply #39 on: May 17, 2005, 04:58:41 AM »
Quote from: MotoDave on May 16, 2005, 07:57:19 PM
Before I dump more money into an ignition system, I'm going to try and determine if I have an ignition problem.  I'm running Champion 810's and they seem to read OK, but the manufacturing on these plugs suck.  although they all have the same protruding length, some actually have longer insulators than others.  It's obvious with the naked eye.  While I had the plugs out I did a cold compression test and got 200,200,205,210 psi in cylinders 1-4.  A far cry from the 160-165 numbers I got before the 836 kit and valves. In any case, I'm going to put different plugs in just in case (the 810's were new.) Any diagnostic suggestions?
Those compression #'s look OK for that kit. Yeah, get rid of those Champions- they are garbage. If you want a great plug get the Denso Iridium. They are not cheap but they are a fantastic plug. Make sure your sparkplug wire boots are good- I've seen weird misfire/poor running situations once the engine is warmed up .You will eventually need a good ignition system especially with the increase in compression- the points are marginal in a stock engine. I also understand it would be nice to further explore the cause of the misfire and narrow down the possibilities.
« Last Edit: May 17, 2005, 06:35:11 AM by MRieck »
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Re: 836 big bore and oil leaks.
« Reply #40 on: May 17, 2005, 11:46:53 AM »
MRieck, what part number iridium plugs did you use?
I think I'll do the Boyer Bransden upgrade for now with the CB900 coils.
Perhaps later I'll bump it up a notch to the Dyna 2000
Thanks for the help,
Dave
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Offline cben750f0

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Re: 836 big bore and oil leaks.
« Reply #41 on: May 17, 2005, 03:59:36 PM »
you might have trouble fitting cb900 coils under the tank...peace..(ps i used vf1000 coils)
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Offline kghost

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Re: 836 big bore and oil leaks.
« Reply #42 on: May 17, 2005, 06:29:35 PM »
I'm running the Accel coils with points. Had to modify the stock coil mounts slightly but they fit under the tank great.
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Offline cben750f0

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Re: 836 big bore and oil leaks.
« Reply #43 on: May 17, 2005, 06:57:07 PM »
i know some of you have seen this, but here it is again...
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you are never to old, to act like a kid... be safe
funny thing,chasing someone down hill on a bike 30 years older than theirs..
he said \\\\\\\'it was like watching a 250kg unguided weapon getting stuck up you bum\\\\\\\ http://www.bikepics.com/members/trixtrem/

Offline MRieck

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Re: 836 big bore and oil leaks.
« Reply #44 on: May 18, 2005, 04:24:27 AM »
Quote from: MotoDave on May 17, 2005, 11:46:53 AM
MRieck, what part number iridium plugs did you use?
I think I'll do the Boyer Bransden upgrade for now with the CB900 coils.
Perhaps later I'll bump it up a notch to the Dyna 2000
Thanks for the help,
Dave
   For the Denso plugs-Standard heat range is   IX-24
                                           1 Step colder is            IX-27
  I run the colder plug.
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MotoDave

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Re: 836 big bore and oil leaks.
« Reply #45 on: May 18, 2005, 09:32:35 AM »
MRieck, what modifications does your bike have?
Wondering how modified an engine has to be to warrant colder plugs.
I threw a set of NGK D8EA plugs in last night and it runs much better.
However, I stil have to do a throttle chop to see if they are of the correct heat range.
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Offline MRieck

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Re: 836 big bore and oil leaks.
« Reply #46 on: May 18, 2005, 09:54:35 AM »
915cc kit with a good amount of compression. It makes alot of heat.
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Offline Sam Green Racing

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Re: 836 big bore and oil leaks.
« Reply #47 on: May 20, 2005, 04:00:58 PM »
Hi all,

Motodave, pleased to hear it's running beter, but as regards the Boyer ignition I have run one for two years with no problems.
The dyna system used by Mrieck sounds a better option and he sounds like he knows what he's talking about.
Have just found out how to send pic's.
« Last Edit: September 01, 2007, 06:55:41 PM by Glenn Stauffer »
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Offline Sam Green Racing

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Re: 836 big bore and oil leaks.
« Reply #48 on: May 21, 2005, 05:13:47 PM »
Hey Terry,

Thanks for the kind words, but if you think it looks good you should hear the sound.
It has cost my mate £7500 to build with a stock motor. We are just starting on a race motor for it.
« Last Edit: May 29, 2005, 07:45:04 AM by Glenn Stauffer »
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Offline Sam Green Racing

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Re: 836 big bore and oil leaks.
« Reply #49 on: July 15, 2005, 09:32:47 PM »
Hi all,

Almost two months have passed since the last post on this thread.
A few weeks ago I let a top tuner in the UK see the Wiseco 836 piston kit we are useing.
His first words, you will have problems with crankcase pressure with these pistons!
He thought that on the underside of the piston it had to many flat surfaces, and that a good tuner/ machine shop could soon put right by shamfering / knife edging these surfaces.

Regards Sam Green.
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