Resend my activation email : Register : Log in 
BCF: Bike Chat Forums


CDI vs POINT - CG125 WITH HIGH HOAD

Reply to topic
Bike Chat Forums Index -> The Workshop
View previous topic : View next topic  
Author Message

abuhafss
L Plate Warrior



Joined: 04 May 2014
Karma :

PostPosted: 12:18 - 04 May 2014    Post subject: CDI vs POINT - CG125 WITH HIGH HOAD Reply with quote

I am continuously facing low power complaints on CG125/CDI with high load as compared to CG125/POINTS with high load.

For example, the two bikes are traveling on a steep road for 1-2 hours continuously. After, say, 2 hours the CG125/CDI would loose its power and would compel the rider to move back to a lower gear. And some sort of ticking sound could be heard from the engine. Whereas, the other bike CG125/POINTS would keep on moving without any problem.

All CG/CDI models would behave similarly. The mechanics also endorse this performance but with no logical reason. The major difference between the two models is the ignition system so, naturally the mind would point out that the CDI is the culprit. I have learnt that CDI is far more efficient than the points and all new models are equipped with different versions of CDI.

I want to know how do we overcome the low power complaints in the CDI models? Some fellows have suggested to modify the exhaust system and/or fuel/air mixing system. Is there any modification for the CDI unit which could make some improvements??
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts
N cee thirty This post is not being displayed because the poster is banned. Unhide this post / all posts.

abuhafss
L Plate Warrior



Joined: 04 May 2014
Karma :

PostPosted: 14:51 - 04 May 2014    Post subject: Reply with quote

Not all the bikes would be having the wear problem, so why all the CDI models behave identically?
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

Teflon-Mike
tl;dr



Joined: 01 Jun 2010
Karma :

PostPosted: 15:06 - 04 May 2014    Post subject: Reply with quote

CDI's have an inbuilt 'advance by retard' system.

The ignition's 'static' timing is set quite advanced, then as revs increase, the black box reduces the delay between trigger signal and actually letting the spark go from the coil.

Points on a CG I believe are 'static timed' with no advance retard mechanism.

Would have to be mechanical, as early points Benley-Motors or OHC CB125's, with bob-weights on the end of the cam-shaft. For low-maintenance economy commuter, that's sophistication and complexity the bikes just don't need. But computerised electronic ignition made it 'cheap and easy'.

However, run a little 125 flat out for long periods, its going to get hot. Hot engine, weak mixture or over advanced spark, you get 'pinking' and bikes loose power.

Later, CDi GS's were lean jetted for better economy and tighter emission controls... so they will be far more likely to get hot, and far more likely to suffer pinking when they do, if thrashed for prolonged periods.

Bottom line is, CDi is not the cause of the 'problem'.. cause of the problem is running a little econno-commuter designed to do 30-40mph with perhaps brief bursts up to 50+, on rural 3rd world roads, 'flat out' for long periods, trying to stay over 50.

Probably compounded by poor maintenance, were valve clearances and the like, carbon deposits will only exacerbate the issue.
____________________
My Webby'Tef's-tQ, loads of stuff about my bikes, my Land-Rovers, and the stuff I do with them!
Current Bikes:'Honda VF1000F' ;'CB750F2N' ;'CB125TD ( 6 3 of em!)'; 'Montesa Cota 248'. Learner FAQ's:= 'U want to Ride a Motorbike! Where Do U start?'
 Back to top
View user's profile Send private message Visit poster's website You must be logged in to rate posts

abuhafss
L Plate Warrior



Joined: 04 May 2014
Karma :

PostPosted: 17:42 - 04 May 2014    Post subject: Reply with quote

CDI has nothing to do with this problem......Okay, got it.

This means, this problem cannot be avoided. And we have to wait until all the POINTS model die so that there is nothing is left for comparison. And one day, we will become use to this issue.

Cannot reach 50mph+ on steep rural road of third word Sad
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

Kickstart
The Oracle



Joined: 04 Feb 2002
Karma :

PostPosted: 18:51 - 04 May 2014    Post subject: Reply with quote

Hi

You could possibly try going up a size on the main jet to richen the mixture a touch, which might lower the running temp a bit. Similarly also check the oil level, or if you are feeling rich add an oil cooler.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

moonzoomer
World Chat Champion



Joined: 01 Jul 2012
Karma :

PostPosted: 21:21 - 04 May 2014    Post subject: Reply with quote

I think one or maybe 2 of the older points model CGs had those silly lean burn carbs that done the engine no good at all. You might be able to fit one of these CDI units that fit the Skyteam 125 Ace model, they have a variable advance and are based on a cg engine.
https://www.ebay.co.uk/itm/Skyteam-Ace-50-125-Performance-CDI-6-pin-Digital-/400702859071?pt=UK_Motorcycle_Parts&hash=item5d4bc0673f
 Back to top
View user's profile Send private message You must be logged in to rate posts

abuhafss
L Plate Warrior



Joined: 04 May 2014
Karma :

PostPosted: 10:52 - 05 May 2014    Post subject: Reply with quote

moonzoomer wrote:
You might be able to fit one of these CDI units that fit the Skyteam 125 Ace model, they have a variable advance and are based on a cg engine.
https://www.ebay.co.uk/itm/Skyteam-Ace-50-125-Performance-CDI-6-pin-Digital-/400702859071?pt=UK_Motorcycle_Parts&hash=item5d4bc0673f


As TEFLON-MIKE and others have pointed out that CDI is not the cause of this problem, how do you think this performance CDI from OORACER would make improvement?
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts
N cee thirty This post is not being displayed because the poster is banned. Unhide this post / all posts.

smegballs
World Chat Champion



Joined: 28 Oct 2007
Karma :

PostPosted: 11:22 - 05 May 2014    Post subject: Reply with quote

Kickstart wrote:
Hi

You could possibly try going up a size on the main jet to richen the mixture a touch, which might lower the running temp a bit. Similarly also check the oil level, or if you are feeling rich add an oil cooler.

All the best

Keith


Out of interest how do you go about adding an oil cooler to an aircooled bike?? Shifty

I have considered it before, but it seemed I had no idea of where to tap into the pressurised oil feed sump.

I've seen the flow of oil on its way to the engine should go.

Sump>Pump>Filter>Cooler>Big end/cams etc
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

Kickstart
The Oracle



Joined: 04 Feb 2002
Karma :

PostPosted: 12:46 - 05 May 2014    Post subject: Reply with quote

Hi

Would depend on the exact engine (and I don't know the oil flow in detail of the CG engine). There are loads of engines which are not liquid cooled which do have oil coolers. The ones that are easiest in general will be those with an external spin on oil filter.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

smegballs
World Chat Champion



Joined: 28 Oct 2007
Karma :

PostPosted: 14:06 - 05 May 2014    Post subject: Reply with quote

Would a "safer" method of oil cooling, be just to tap from the sump, use an automotive fuel pump to push the oil through a cooler which drains back to the sump.

You could put a check valve or two in the system so the pump is always primed with oil, plus a thermo switch of somekind to only operate the pump when the oil temps are high. Plus if you don't wan't to the system any more a couple of plugs and its off.
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

Kickstart
The Oracle



Joined: 04 Feb 2002
Karma :

PostPosted: 14:15 - 05 May 2014    Post subject: Reply with quote

Hi

Not sure a normal car fuel pump would cope with the heat, higher viscosity and flow rate (although on the last the flow rate of a CG125 is probably pretty low so likely not something to worry about). Would probably be easier to just squirt cool water from a reservoir over the engine every so often.

But as there is already a pump pushing oil around it doesn't seem worthwhile to add another pump.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

smegballs
World Chat Champion



Joined: 28 Oct 2007
Karma :

PostPosted: 14:35 - 05 May 2014    Post subject: Reply with quote

I'm thinking more of my GN250 than a CG, seeing as I'm planning to run it for long periods in hot countries (35-40 deg C air temp) this summer.

Found these on advrider:

https://i1210.photobucket.com/albums/cc416/lizrdbrth/brianscool.jpg

Which is obviously the kind of thing that is required, here fitted to a TW200.

They explain its operation as:

Quote:
This engine family uses submersion-oiled roller bearings in its bottom end, and the small rod end, piston skirts and tranny gears are splash-oiled. The oil pump in this motor pretty much exists solely to serve the cam bearings and operates at a very low pressure (10 PSI, or less).

This difference is significant in that a cooler does not interrupt any high-pressure main arteries as it would on an engine with babbit-type bearings. Hence no need for braided stainless or hard lines. More on this later.

Any oil not used to feed the cam is bypassed to the crankcase. It is this bypass oil which is being re-routed and cooled.


I just checked the GN's fiches and it seems that the big-end is needles and the mains balls, so may well be a similar system? I guess it's just a matter of how to tap into the bypass feed.

https://i.imgur.com/APV7nxV.png

The GN's oil pressure should be between 0.3-0.7 km/cm2, when tested. This works out as 4.3-10psi, so it does seem that the GN doesn't run a high pressure oil system.


Last edited by smegballs on 14:41 - 05 May 2014; edited 1 time in total
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

Kickstart
The Oracle



Joined: 04 Feb 2002
Karma :

PostPosted: 14:40 - 05 May 2014    Post subject: Reply with quote

Hi

If the bypass is significant then that might well do it.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

Teflon-Mike
tl;dr



Joined: 01 Jun 2010
Karma :

PostPosted: 14:47 - 05 May 2014    Post subject: Reply with quote

smegballs wrote:
I'm thinking more of my GN250 than a CG, seeing as I'm planning to run it for long periods in hot countries (35-40 deg C air temp) this summer.

There's a much simpler, more reliable and tidier way to solve the POSSIBLE problem your bike may overheat on the way to Portugal.

Stop frequently to take photos; have a drink; have a pee; or check your map; don't 'thrash' the bike, or so long, without letting it cool down a bit.

You are much less likely to waste as much time on your trip stopped in lay-bys doing that, than 'developing' an un-tested auxilliary cooling sytem that could be utterly unnecessary.
____________________
My Webby'Tef's-tQ, loads of stuff about my bikes, my Land-Rovers, and the stuff I do with them!
Current Bikes:'Honda VF1000F' ;'CB750F2N' ;'CB125TD ( 6 3 of em!)'; 'Montesa Cota 248'. Learner FAQ's:= 'U want to Ride a Motorbike! Where Do U start?'
 Back to top
View user's profile Send private message Visit poster's website You must be logged in to rate posts

Kickstart
The Oracle



Joined: 04 Feb 2002
Karma :

PostPosted: 14:57 - 05 May 2014    Post subject: Reply with quote

smegballs wrote:
I just checked the GN's fiches and it seems that the big-end is needles and the mains balls, so may well be a similar system? I guess it's just a matter of how to tap into the bypass feed.


May well be, but could also still pump that oil through the bottom end bearings rather than relying on splash lube.

That said, thinking about it in this situation I think I agree with Tef. 30~40 degrees isn't [i]that[/] hot. The original suggestion was for an engine that is showing signs of issues that could well be temp related. If you want to ride it flat out the whole way on holiday and notice such a loss in performance then you might well have a long push or wait at some point Laughing .

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts
unitynotsocri... This post is not being displayed because the poster is banned. Unhide this post / all posts.

smegballs
World Chat Champion



Joined: 28 Oct 2007
Karma :

PostPosted: 15:20 - 05 May 2014    Post subject: Reply with quote

Okay, okay. To be honest I wasn't too fond of the idea of drilling/tapping my clutch cover/crankcases.

I have found however a nice oil temp gauge, plus a sump plug adapterising device that allows me to screw the 1/8 npt temp sender right into the sump plug. That way I can just watch the nice guage whilst riding.

I only plan to cruise the GN at 50-55 or so, I feel mean making it go faster as the rev needle looms further to the redline than I'd like. Funny as on my 125 I'd just have the throttle pinned to the stop and not care less, leading to faster speed overall.
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts
unitynotsocri... This post is not being displayed because the poster is banned. Unhide this post / all posts.

Teflon-Mike
tl;dr



Joined: 01 Jun 2010
Karma :

PostPosted: 15:42 - 05 May 2014    Post subject: Reply with quote

smegballs wrote:
I have found however a nice oil temp gauge, plus a sump plug adapterising device that allows me to screw the 1/8 npt temp sender right into the sump plug. That way I can just watch the nice guage whilst riding.

I think you are trying to over-prep this bike for your trip still; remember first advice I offered; before looking for more than standard, make sure you have what you should AS standard.

Anyway; my main concern on a long run like that would be keeping the motor oil tight. So more standard the better.

For oil temp guage, I would probably use one of those cheap maplin 'turkey-temp' thingies, and stick it no the OUTSIDE of the rocker cover, to give me idea of running temp, without any added leak-points. I dont need to know how hot the oil is to within half a degree.. just whether the motor's getting a bit warm and could do with a rest, and its the top of the engine that's the important bit, not the sump.

As for oil cooling; probably redundant on your bike, I suspect it has vertically split crank cases; so just for academic interest; on bikes with horizontally split cases, and a separate 'sump-pan', old trick for race/rally prep was a deep sump, or sump extender, basically a bit of perhaps 1/2 ali plate cut to the shape of the sump gasket, fitted between sump and block with two sump gaskets to increase sump volume.

For some engines you could actually buy deep sumps, that held maybe an extra pint of oil, so it had more time to settle and cool before being re-circulated, and extending oil change intervals. They often had extra and deeper finning on them to help add extra oil cooling. This is of course old-tech from days before reliable higher pressure recirculating oil systems allowed forced cooling through a remote heat exchanger; but still useful and valid principle.
____________________
My Webby'Tef's-tQ, loads of stuff about my bikes, my Land-Rovers, and the stuff I do with them!
Current Bikes:'Honda VF1000F' ;'CB750F2N' ;'CB125TD ( 6 3 of em!)'; 'Montesa Cota 248'. Learner FAQ's:= 'U want to Ride a Motorbike! Where Do U start?'
 Back to top
View user's profile Send private message Visit poster's website You must be logged in to rate posts

Cyclingbiker
Spanner Monkey



Joined: 05 Aug 2012
Karma :

PostPosted: 17:48 - 05 May 2014    Post subject: Reply with quote

Points CG's actually do have an advance/retard mechanism on the flywheel. The are bob weights which change the position of the cam that moves the points relative to the crank, so the ignition timing varies according to engine speed.
____________________
Honda CB500s (1999) - Honda CG 125 BR-J (1991)

Mod 1 - Passed - 12/11/12 --- Mod 2 - Passed - 26/11/12
 Back to top
View user's profile Send private message You must be logged in to rate posts
Old Thread Alert!

The last post was made 12 years, 195 days ago. Instead of replying here, would creating a new thread be more useful?
  Display posts from previous:   
This page may contain affiliate links, which means we may earn a small commission if a visitor clicks through and makes a purchase. By clicking on an affiliate link, you accept that third-party cookies will be set.

Post new topic   Reply to topic    Bike Chat Forums Index -> The Workshop All times are GMT
Page 1 of 1

 
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum

Read the Terms of Use! - Powered by phpBB © phpBB Group
 

Debug Mode: ON - Server: biskey (www) - Page Generation Time: 0.10 Sec - Server Load: 0.33 - MySQL Queries: 13 - Page Size: 129.17 Kb