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Message started by James Lynch on 02/28/17 at 11:23:20

Title: Mid Range Failure - timing or ??
Post by James Lynch on 02/28/17 at 11:23:20

Hello! As the new season approaches I am working with my local shop to diagnose and fix a problem that crept up last year, we are all ears and hoping someone can shed a little light on what may be happening and how to address the issue. Here's the scoop -

86 Savage, had it 4 years, runs beautifully when it runs. Nothing too major done to it but I have swapped for a Raptor petcock, it uses a K&N filter, and I went up a size on my main jet and did the spacer mod (it was already done I just replaced the washer once) which decreased backfiring and ran a little stronger. Otherwise I have replaced the iginition coil and starter when they began to falter but no other special work to it.

Late last year it began to cut out at mid range RPM, whether in gear or not. It would idle strong, then when gassed it would rev up and begin to 'miss' then backfire, then choke out if you did not let off the accelerator back to idle. As it would continue to idle it would get worse quickly, eventually failing at lower RPM and not recovering at all. I would let it sit a while, usually charge the battery or something, and repeat the process.

I have the bike at Moto Classic Garage in Los Angeles, good guys and familiar actually somewhat with the Savage. They cleaned and checked the carb, checked the plugs, compression, fuel system, and went through some basic diagnostics. They have another Savage in the shop and have even gone through swapping pieces between the bikes to try and find the problem but no luck yet. One mechanic thinks it is related to timing but not sure how to be sure, the other wants to plug into another black box and see if that reveals anything.

So I am asking for any advice or suggestions, we are all pretty curious at this point what is happening ha, and as it gets warmer every day I am certainly motivated to get it back on the road. Would the cam chain adjustor play a role in such a problem? Is there another way to check the timing or a related component we have not tried? Does this sound like a problem we simply haven't thought to look for? Or is the black box truly the next thing to swap?

Thanks so much in advance, this site is a great resource!

Title: Re: Mid Range Failure - timing or ??
Post by verslagen1 on 02/28/17 at 11:47:06

There's not much you can do with the timing. Electronic pickup under the stator cover with the advance controlled electronically by the TDI. Black boxes for the 86 thru 88 are not compatible with later years due to the connector and timing.

But, 30 yr old electronics are suspect, solder joints just don't last forever.

I suggest you go back to stock jetting and spacer to see the result. The 86 is already rich and unless you have a straight pipe shouldn't need a larger jet. If fact my 88 I went down a size.

Regarding the cam chain, have you checked it? what mileage? If it has jumped a cog (highly unlikely) it could limit the high end.

Title: Re: Mid Range Failure - timing or ??
Post by ohiomoto on 02/28/17 at 11:50:16

Sounds like a lack of fuel to me. I would check the float level. Maybe even swap carbs if they have one.

I guess the ignitor or CDI box could be bad.

I have a couple of spares (carbs and ignitor boxes) if you end up needing one, but is sounds like the place you are working with has stuff.

Title: Re: Mid Range Failure - timing or ??
Post by James Lynch on 02/28/17 at 14:30:03

Thanks for the input here, I will share this with the garage as well. A couple notes though to further clarify regarding your suggestions -

They swapped carbs on it with a nicely functioning one off another savage and the same issue occurred. It does feel like a fuel issue however here is the strange part - it doesn't sputter or anything as it approaches it's fail point, and once it hits it there is a total loss of ignition until it catches again, not just a quick misfire. This led the guys to look electrical issues possibly after checking the fuel system and plug.

I'll point them to this thread and see if they have some more details, thanks!

Title: Re: Mid Range Failure - timing or ??
Post by stewmills on 02/28/17 at 14:55:54

Did you do anything to the muffler? Maybe too little or too much back pressure (a plug loose and twisted sideways or either no plug at all?).

Just another thing to consider. Our bikes need the back pressure to work properly and major increases or decreases ca impede performance.

Good luck.

Title: Re: Mid Range Failure - timing or ??
Post by batman on 02/28/17 at 15:25:07

Your using the raptor petcock ,I'd check to make sure whatever was used to plug the port for the vacuum line isn't leaking, and causing the motor to run lean. I'd also take a look at the carb diaphragm for pinhole leaks and the TEV valve and passages if they weren't cleaned.Make sure the washer is put back in place just above the main jet,it holds the needle jet up in place ,and the carb will run super rich(flood) above idle without it.Let us know how you make out.

Title: Re: Mid Range Failure - timing or ??
Post by Ed L. on 02/28/17 at 17:23:27

Check your side stand safety switch, they have a bad habit of acting up and shutting off the engine.

Title: Re: Mid Range Failure - timing or ??
Post by James Lynch on 02/28/17 at 18:08:53

This is all great input right off the bat, thanks! I'm going to stop by tomorrow and talk through them with the guys, I'll report back from there.

Concerning muffler though, I never touched it but it is an aftermarket exhaust, I think close to stock just cut a little shorter and straighter at the end I'll try to grab a pic if interested more on that.

Concerning the petcock, I'll double check good idea, I plugged it with a nice little rubber cap fit snugly and replaced it actually about a year and a half ago because the original one I used began to look weathered and brittle. I'll double check all the fittings tomorrow though and go over the questions about carb and washer to check all points.

And ed I'm actually unaware of the side stand safety switch? Is that something the 86 models have? I just haven't ever seen that mentioned, will check it out though thanks!

Title: Re: Mid Range Failure - timing or ??
Post by justin_o_guy2 on 02/28/17 at 20:27:53

I'd hafta hook an induction timing light on the plug wire and see how the ignition system is acting. It's either gonna be flashing so fast it looks like a steady lite or not. At 3,500 rpm you'll get 7,000 flashes a minute.Will that fry one? IDK..
I've heard of spark plugs breaking down under load,
If I saw steady ignition by the light, I'd swap out the plug. Easy as that is, I'd probably start there. Crud hides next to the plug, blow it clear first, examine, whatever you are comfortable with.

Title: Re: Mid Range Failure - timing or ??
Post by Dave on 03/01/17 at 03:57:51

2C2B352A28252E460 wrote:

They cleaned and checked the carb, checked the plugs

Did they replace the plug with a new one?

It is impossible to look at a plug and tell if it is any good...what matters is what it does when the engine is running and under load.

Title: Re: Mid Range Failure - timing or ??
Post by hotrod on 03/01/17 at 06:32:16

Good luck. At least you can be comfortable knowing that your bike is in good hands.

Title: Re: Mid Range Failure - timing or ??
Post by Kenny G on 03/01/17 at 06:56:12

James,

Don't overlook checking that the gas cap is venting properly.

Over the course of riding for 65 years I have had clogged fuel tank vents, and partially clogged fuel tank vents, more often than I like to admit.

I would say this can be one of the most elusive conditions to detect.

Kenny G :-/

Title: Re: Mid Range Failure - timing or ??
Post by justin_o_guy2 on 03/01/17 at 08:29:12

504F494E53546555655D4F43083A0 wrote:

Sure,the mechanic can swap out the ignition, If they're compatible. Some year models don't work with the wrong year model engine, or so I have, possibly, wrongly gathered here.
A timing light would seem like such an easy test.

Title: Re: Mid Range Failure - timing or ??
Post by HAPPYDAN on 03/01/17 at 13:13:50

4668634E7F6C7E650D0 wrote:

No kidding. I picked up a cobbled-up Honda CT110 last summer. Originally a Cal version with the charcoal canister attached to the fuel tank. Owner had plugged the line to the canister. It ran fine for 5 minutes, then sputtered and conked out. Push home, check everything, find nothing, scratch head. Kick over, starts right up, 5 minutes, conks out. Disconnect canister, problem solved. Solution: The canister line was the tank vent. Order vented gas cap, all is now well. Open the tank and run it to see if that helps.

Title: Re: Mid Range Failure - timing or ??
Post by Kenny G on 03/01/17 at 13:56:05

Dan,

I have had similar problems to darned often over the years. If anything acts up on the engine the first thing I do is loosen the gas cap and see if the problem goes away.

Kenny G :-/

Title: Re: Mid Range Failure - timing or ??
Post by jcstokes on 03/01/17 at 17:41:31

What sort and size Raptor did you use?

Title: Re: Mid Range Failure - timing or ??
Post by justin_o_guy2 on 03/01/17 at 19:00:34

454C5C5B40444A5C2F0 wrote:

What sort and size Raptor did you use?

The question is
Did you put a $12.00 Chinese turd on it or a Gin U Wine Yammyhammer petcock on it?

Title: Re: Mid Range Failure - timing or ??
Post by batman on 03/02/17 at 08:38:30

Not only did the 86 have a side stand safety switch,this switch had a warning light ,it's to the right of the neutral light in the speedometer.That being said I don't think it has much to due with your problem, I would be suspect of the spark coil/plug wire ,it may well be weak due to age. the coil to work well must build a strong field in the primary loop ,in a matter of milliseconds ,the faster the RPM the less time it has,so at idle speeds it could be producing a good spark ,but at higher speeds the spark could be falling off an not high enough to jump the gap at the plug.(the plug wire core is carbon impregnated fiberglass ,and can fail in as little as 5 years)I'd try swapping the coil off the bike they have that's running.You have fuel ,compression,that only leaves spark. If the CDI was toast the bike wouldn't run,the CDI retards timeing to help the bike start, and only advances the timing about 5 degrees @ about 5000 rpm ,that leaves the coil (has it ever been changed?). It's the number one suspect in my book.Did you replace the coil with a after market coil? or a used coil? either could be a problem. An aftermarket coil could have less resistance and cause flyback , that hurts proper operation of the coil and could damage the TDI.You could have a bad or loose connection, or a bad stock coil , which you could test, 1-7 ohms for the primary , 10,000 to 25,000 ohms for the secondary.

Title: Re: Mid Range Failure - timing or ??
Post by James Lynch on 04/20/17 at 15:07:44

It was the cdi box! Went through everything else and finally swapped it out, runs great again! Ha, what a ride, thank you everyone for your suggestions :)

Title: Re: Mid Range Failure - timing or ??
Post by LANCER on 04/20/17 at 17:26:44

If you have issues in the future, stop by here first...it may save you some time.

Title: Re: Mid Range Failure - timing or ??
Post by ohiomoto on 04/21/17 at 05:03:07

5F5846595B565D350 wrote:

It was the cdi box! Went through everything else and finally swapped it out, runs great again! Ha, what a ride, thank you everyone for your suggestions :)

----------------------------

Good news! Glad it worked out for you. I guess you'll have some carbs for sale soon. Someone was looking for one the other day.

Title: Re: Mid Range Failure - timing or ??
Post by James Lynch on 04/24/17 at 10:42:58

Absolutely, thank you for the package! I'll list them here for anyone and pass the savings on, so happy to be back on the road :)