Honda TRX350 -- irregular running, stalls?

[Mursal]

Yes evenings are gone now, leaving it very hard to get anything extra done. But sometimes its good to leave them for a bit to go back with a fresh approach. Yes sorry about that, ICM and CDi box will be the same thing.
ICM = Ignition Control module
CDi = Capacitor Discharge Ignition.

Coil testing:
Disconnect the two wire plug from the coil.
Connect the green terminal (that was going to the green wire) to negative on battery, or the bike chassis.
Spark plug on cylinder head.
Connect the black / yellow terminal (that was going to the BL/Y wire) to the positive terminal on the battery, but just for a moment, when you disconnect it you should see a spark across the spark plug? Just do the test 2 or 3 times, the spark might be weak, but that's fine the control box will do the rest.

In the previous post, wires I mentioned are from problems we had with other quads in the past and if you do get a spark from disconnection the wires mentioned, I can explain why, later.

Them quads are feckers when they stop ..............

 

[Mursal]

I have now found resistance figures for the ignition coil and a diagram, have you that diagram?

Primary winding resistance = 0.1 to 1.2 Ohms
Secondary winding resistance = 3600 to 4500 Ohms with no plug cap
Secondary winding resistance with the plug cap still in place = 8100 - 10,000 Ohms

I can post diagram if you need it ............

 

[Dry Rot]

Yes evenings are gone now, leaving it very hard to get anything extra done. But sometimes its good to leave them for a bit to go back with a fresh approach. Yes sorry about that, ICM and CDi box will be the same thing.
ICM = Ignition Control module
CDi = Capacitor Discharge Ignition.

Coil testing:
Disconnect the two wire plug from the coil.
Connect the green terminal (that was going to the green wire) to negative on battery, or the bike chassis.
Spark plug on cylinder head.
Connect the black / yellow terminal (that was going to the BL/Y wire) to the positive terminal on the battery, but just for a moment, when you disconnect it you should see a spark across the spark plug? Just do the test 2 or 3 times, the spark might be weak, but that's fine the control box will do the rest.

In the previous post, wires I mentioned are from problems we had with other quads in the past and if you do get a spark from disconnection the wires mentioned, I can explain why, later.

Them quads are feckers when they stop ..............

The Clymer manual says the following about the ignition coil, "The ignition coil can be tested without removing it......Connect the positive test probe to the black/yellow on the ignition coil and connect the negative test lead to ground....crank the engine for a few seconds....the minimum peak voltage is 100v".

I've done that and there is no reading on the volt meter at all. Only a minimal momentary reading (0.1v) when I stop cranking. I've paraphrased that a bit as it's obvious it must be switched on, etc!

Wouldn't that suggest that the ignition coil is toast? And would it be worth trying a £10 one off ebay? I'll try the tests you suggest in the morning. Sorry about ICM/CDi. Posts on other forums refer to both.

 

[ROBINWORKS]

You will require a peak voltage tester to do the coil test. A small plug in unit that goes between the multitester and the coil

 

[Mursal]

Yes definitely worth a £10 even just to have it as a spare.

And yes it points towards the coil, or from past experience the CDi box which provides that voltage spike across the primary of the coil. Possibly its not allowed to create the spike, because one of the control wires for the CDi box are going to earth (this is how it kills the spark to stop the engine).
Possibly getting an earth either through the voltage regulator or faulty neutral switch, hence why I suggested to disconnect to test.

Maybe not that at all, but its an easy test to disconnect the wires then go for a spark.

 

[Dry Rot]

You will require a peak voltage tester to do the coil test. A small plug in unit that goes between the multitester and the coil

Yes, the manual says ideally it needs a peak voltage meter, but can be done with the above test. . The Clymer manual is pretty good. Surely, if there was any life in it, there'd be some movement on the multimeter display?

The first manual I had for the old TRX300 was a Haynes manual, popularly known as the Haynes book of lies. It had me trying to fit the gear box back together with a washer that shouldn't have been there (local Honda mechanic told me there shouldn't be one!) and I threw out a perfectly good clutch which (apparently) ws out of spec!

 

[Dry Rot]

Yes definitely worth a £10 even just to have it as a spare.

And yes it points towards the coil, or from past experience the CDi box which provides that voltage spike across the primary of the coil. Possibly its not allowed to create the spike, because one of the control wires for the CDi box are going to earth (this is how it kills the spark to stop the engine).
Possibly getting an earth either through the voltage regulator or faulty neutral switch, hence why I suggested to disconnect to test.

Maybe not that at all, but its an easy test to disconnect the wires then go for a spark.

New coil on order -- from a UK address. Should be here in a few days. It amazes me how old uncomplicated stuff, like the old MF135, just keeps going compared with this moderrn stuff. Always starts on the button and is no problem to fix IF something does go wrong.

 

[Mursal]

The quads can be right little feckers .........

 

[Netherfield]

www.lsengineers.co.uk might have been able to supply the coil, stock quite a lot of small engine parts.

 

[Dry Rot]

Ordered one of these. If it doesn't last long, that's fine so long as it tells me the existing coil is bad! £8 including postage.

https://www.ebay.co.uk/itm/Honda-TR...h=item2c9a76768c:g:tjkAAOSwydRbjpOY:rk:3:pf:0

 

[General-Lee]

Ordered one of these. If it doesn't last long, that's fine so long as it tells me the existing coil is bad! £8 including postage.

https://www.ebay.co.uk/itm/Honda-TR...h=item2c9a76768c:g:tjkAAOSwydRbjpOY:rk:3:pf:0

You’re gonna end up with a complete new one!

 

[Mursal]

Ordered one of these.

Let us know how things go ..............

 

[Dry Rot]

You’re gonna end up with a complete new one!

Not far off that now! It already has a Chinese pot and piston set from a previous disaster. Only £130 including carriage.

Let us know how things go ..............

Yes, I will. Quite amused to see how these guys sell parts. It is obviously the same ignition coil but with lots of different prices for different models! Can't all be different, can they?

 

[Dry Rot]

Well, the cheap ignition coil has arrived and still no spark.

I've done some more research. The official manual only describes peak voltage tests for the coil and I think that needs special equipment. However, I have found a 'No spark check list" for a TRX450 with resistance tests and the specifications are said to be similar to other Honda quads.

Original ignition coil
Test across primary lugs should be 0.1 to 1.0 ohms.
It's actually 0.7.
Test from primary lugs to secondary 6.5K to 9.8K ohms
It's actually 3.03K.

Does that means it's probably bad?

New coil
Across primary lugs 1.1
Primary to secondary 1.80K
?

I am tempted to give up and take it in to the dealers, except I know it is going to cost me! I've started taking connectors apart and cleaning them up. They are difficult to dismantle!

 

[Mursal]

Only now saw your reply, sorry about that.

 

[Dry Rot]

Only now saw your reply, sorry about that.

No problem. You have done pretty well so far!

Started ripping the panels off so I can check the wiring and put switch cleaner in the connectors. Oh the joys!

 

[El Gordo]

Have you checked the voltage regulator?
Some Hondas have a wire from reg to cdi, pink wire I think. Nobody could ever tell me what its purpose is but it can result in no spark or a erratic spark.
As far as I recall you don't need a voltge reg plugged in for the bike to run, i.e. unplug the reg and see if it starts!

 

[Dry Rot]

To resurrect this thread, the problem with my Honda quad was irregular running, then no spark. The various problems have been intermittent and inconsistent and very difficult to pin down. I've found this is not unique. This is an update (I'd hardly call it a 'progress report'!). "No spark" in Honda quads seems to be a very common problem!

I haven't done much with the quad as I have been busy on other jobs and don't need it right now. Since connectors seem to be a regular problem, I decided to take apart as many as possible in odd moments, clean them up, and reassemble with dielectric grease, and at the same time check resistances with whatever data I could find online. I have come to realise why the manual talks about measuring peak voltages rather than resistances. Frankly, although I've checked the reistances of the coils (I got a new cheap Chinese one to try), I still don't know if they are working or not. Both could be faulty!

So I started doing some research into this peak voltage stuff. The "proper" equipment costs megabucks. Further research reveals that a digital voltmeter can be used to measure peak voltage using a device that would effectively delay the signal, called a DVA adaptor. The signals to be measured from the engine are so brief that a straight multimeter can't measure them, but by using an adaptor, they can. There's one of these adaptors on Amazon by ES Speciatities for £61 (https://www.amazon.co.uk/ELECTRONIC-SPECIALTIES-640-DVA-Adapter/dp/B0093U3TFG). The exact same item sells in the USA for about $25. A bit more searching brought up details of a DIY version of the same tool. There are only three basic components in the box costing under £2 in the USA, but with £15 shipping! It really is a very simple DIY job to make one. So, rip off Britain again. Details here: https://forums.iboats.com/forum/eng...0403-how-to-make-a-dva-adapter-for-multimeter .

The next problem is accessing the components. Easy enough from the USA, but they ought to be available here in the UK and I'm damned if I am paying £15 on carriage (with possible tax and duty on top). . Still working on that.

I've done a lot of research on this 'no spark' problem and there are several ingenious solutions to identify the source. One clever chap bought cheap Chinese components (total cost under £20), made up a separate wiring harness which he could plug into any quad to by pass the existing electronics, to get it to run. If that didn't work, he could safely conclude that the fault was elsewhere, probably in the wiring. But I haven't resorted to that yet! There is no way to test the CDI unit except to swop it for a known good one which, from Honda, cost around £150.

(Yeah, I know, I've probably got a screw loose somewhere but I'm not going to be beaten by this damn thing even if I have to rebuilt it from scratch! And the DVA adaptor looks like being a useful piece of equipment now most modern engines have electronic ignition controlled by a CDi).

 

[ollie989898]

I know nothing about quad bike gubbinz but I can tell you, that having followed the advice of a friend and run a variety of smaller four and two stroke engines on shell V power petrol, they definitely seem to run better. It is obviously pricier per litre but with the modest quantities involved, and the carefree nature most quadbikes are run, I can't help but think such a switch would be a very good idea if it helps keep the internals cleaner. Obviously it won't help with an ignition fault but it does help keep the machine gods a bit happier.

 

[Dry Rot]

I know nothing about quad bike gubbinz but I can tell you, that having followed the advice of a friend and run a variety of smaller four and two stroke engines on shell V power petrol, they definitely seem to run better. It is obviously pricier per litre but with the modest quantities involved, and the carefree nature most quadbikes are run, I can't help but think such a switch would be a very good idea if it helps keep the internals cleaner. Obviously it won't help with an ignition fault but it does help keep the machine gods a bit happier.

Yes, I think you are right. One type of petrol is more liable to cause "varnish" to be deposited inside the carburettor etc. than others. When they don't work, one of the first recommendations is to change the fuel and spray carb cleaner in the air intake.