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Kicking and kicking and won't start...

9K views 26 replies 12 participants last post by  Nanonevol 
#1 ·
I’ve been having some problems with my ’66 Bonneville ever since I got it. Never really ran right even after going through every main/pilot jet combination. Long story short I ordered a new needle jet and needle, opened up the timing chest and re-aligned the cams to ensure correctness, reset everything to stock and now the bike won’t even fire up, worse than before. I should add it's been maybe three months since I last touched it.

At first I thought my carburetors were too big (running dual 32mm Mikunis), but after doing a lot of research and talking to a guy who had his running perfect with 36mms I came to decide it wasn’t the problem. So here’s the setup for the carburetors that I’m now running.

Pilot – 30
Main – 200
Air Jet – 2.0
Needle Jet – 159 P4
Needle- 6DH2
Slide – 2.5

Ignition is a Boyer Micro mk.IV, running off a battery that’s putting out >10 volts and also hooked up to a charger while I’ve been working on it.

B8ES plugs.

I literally can’t even get the bike running now, even on starting fluid. Sometimes it’ll fire two or three times and then dies, no matter if the enrichener is on or off. I’ve static timed the Boyer system a thousand times, but I can’t even get it running enough to put a light on it. Also checked for spark and compression, and both cylinders are making about 120psi.

I feel pretty positive that my jetting for these carbs should not be giving me this much trouble. And now that I know the cam timing is reset to factory timing marks I can rule out that too. But leg can only handle so much kicking :(

Any ideas? I've attached a photo of the cam alignment.... just in case.... http://imgur.com/a/G7BxE
 
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#5 ·
Pop the stator cover open, line up the marks on the alternator, and then on the timing side, line up the dot on the Boyer rotor with the clockwise timing hole in the plate.

Yes, I know 10v is low but I think that's the threshold that the Boyer doesn't automatically retard itself at. I was trying to communicate that the battery was good. Measured it when I got home from work and it read 13.15 volts which is normal.

Try Champion N3C plugs.
1. Check your valve adjustment

2. 10V is WAY too low for Boyer (the worst for low voltage of all ignition systems made)

3. DEFINITELY Champion N3C plugs as already stated

4. You should have either resistor plugs, or resistor plug caps, NOT both.

5. Stop using starting fluid

6. May need to strip the carbs and soak the bodies and low speed jets in a gallon can of warm Berryman's Chem Dip for 30 minutes, then re-assemble.

Hope you get on okay...
Yes, I loosened off on the valves to make it easier to set the cam timing and then reset the clearances afterwards.

So this is the first I've heard about the resistor plugs/plug caps. Are you saying that I have both on there currently? The caps I believe are the NGK resistor type, that were on there when I got it, but I have no idea what a resistor plug is. This is new to me... but I have some trouble believing that swapping the spark plug type could fix this problem. The local vintage guy uses the B8ES or B9ES in everything, and they run fine?

I'll definitely try a pair tomorrow though.
 
#4 ·
1. Check your valve adjustment

2. 10V is WAY too low for Boyer (the worst for low voltage of all ignition systems made)

3. DEFINITELY Champion N3C plugs as already stated

4. You should have either resistor plugs, or resistor plug caps, NOT both.

5. Stop using starting fluid

6. May need to strip the carbs and soak the bodies and low speed jets in a gallon can of warm Berryman's Chem Dip for 30 minutes, then re-assemble.

Hope you get on okay...
 
#6 ·
It's never going to start with a Boyer & that battery voltage.

Get a new battery THEN check your running alternator output, then do a plug chop & go from there with mixtures.
 
#7 ·
Since 66 did not originally have the primary side inspection plate and pointer it's best to check. When you say you re aligned the cam wheels were they not set as standard when you started?

What have you set your valve clearances to?

Do you have a consistent spark at the plugs?

Can your battery keep the headlamp on and bright for at least one minute?

Rod
 
#8 ·
It occurred to me that "re-setting the cam timing" could have involved rotating the cams independently to re-align the marks with the head still in place, certainly NOT advisable!

However, you mentioned you loosened the valves first, so likely there was no collision (I hope). It doesn't take much to cause enough damage to never be right again until nicked valve(s) are replaced.

I'm not saying you have resistor plugs and/or caps, but with an electronic ignition you SHOULD have one or the other.
 
#9 ·
It hasn't run at all, since you "fixed" the valve timing. Coincidence?

Like most Triumph riders, I have no advice at all to give you about Mikuni settings or use. Modifications like fitting alien carburettors are best tackled by experts.

Are the spark plugs clean? Have you tried wiring + and - on the Boyer directly to a fully charged battery, bypassing the bike's wiring loom?

It's also quite common to have resistance or loss of connection somewhere in the leads from Boyer box to the trigger plate.
 
#13 ·
Not necessarily G/Paul. If the pinions are not fitted as per stock they simply need to be returned to their proper positions (preferably with the pistons half way down the bore), the timing set and the engine turned carefully to check for clearance before seeing if it will run. If not, then it's time for the degree wheel. Chances are that if the cam timing lined up then the pinions are in the right position on the cam but the OP would have needed to turn the engine over and over and wait for them to align. If he simply popped the intermediate wheel and re set the timing we will never know.

We need to hear back from 650 before bombarding him with more information that could cause confusion.

TT, agree completely about Alien carbs but hey, each to their own.

Rod
 
#15 ·
As mentioned, start with the basics. First, put the ether away. Triumphs are not hard to start if everything is OK. You mentioned that you have a good battery. That doesn't mean that you have good electrical power to your electronic ignition. Measure the voltage at the input to your electronic ignition. If the voltage is correct, pull both plugs and connect plug wire to each plug. Turn off fuel petcocks and turn on ignition. Lay the plugs on the head and turn the engine over by hand, watching that each spark plug fires and you have a good spark. Do this repeatedly to make sure that the ignition isn't erratic. Check to make sure the ignition timing is correct. If these tests are successful, return to the valve timing and confirm absolutely that the valve timing is correct. I'm suspicious that you have accidentally changed the valve timing. Bottom line is that if you have reliable spark, valve timing is correct and you have fuel, it should start. Even if one carb is screwed up, it is unlikely that both are, but this is also possible. Again, forget the ether!
 
#17 ·
Sorry for the late reply, but I went back over everyone's suggestions for the millionth time. I have a degree wheel and used it to check that the rotor on on the alternator is in the correct position and hasn't loosened up or moved around, and that the mark was at 38 degrees BTDC. I also pulled the cam chest again and made sure the cam gears were on the correct keyway, and aligned correctly. I also put in a new battery/spark plugs since they're $20. Still no changes at all. Sometimes I can get the bike to start and idle terribly (backfire out exhaust) with starting fluid and the enrichener on, but it's never consistent and doesn't do anything unless I use starting fluid, and even then most of the time it just kicks back.

So overall have made exactly no progress and discovered nothing new. Still taking suggestions.
 
#20 ·
I'm getting a good spark, but the Boyer's don't fire under 300 (?) RPM, so it's impossible for me to check if it sparks consistently at the same place, but I can put a timing light on it sorta sometimes and it seems like it is in fact firing consistently, but if you have a better way to be positive everything's functioning correctly, I'll try that.

I have never had any luck with Mikunis even though they are simple to work on, and would definitely put Amals on there, but the threads on the intake spigot on the head of this bike were stripped and the flange for the Mikunis was actually welded/brazed onto the head, so I can't change them without getting a new head.

I didn't get the cam wheels aligned to check whether they were in the correct position to begin with, but since everything is the same my gut feeling says that they were, and yes, timing the Boyer in the correct hole.
 
#23 ·
Thanks, but I really don't want to spend any more money on this thing. I've already payed more than twice what I paid for the bike having people look at it and it still has problems and I honestly doubt putting Amals on would help it to run any better at this point.

If you can see the timing light flashing consistently there is a good chance that side of the system is ok, you did say sort of though? How old are the spark plugs, are they heavily fuel fouled?

If originality is a concern then 66 models were fitted with twin 389/95 Monobloc carbs.

Rod
Well, it's pretty difficult to start the bike and keep my hand on the throttle so it won't die, and also bend down while the bike is on the sidestand and shine the timing light into the inspection cover all by myself. :smile2: But from what I can tell, yeah, the ignition seems to be functioning correctly.

Plugs are brand new B8ES. I've played around with the B9ES too and Champions and nothing makes a difference. They seem like a normal wetness to me? Not dripping wet or anything and not really dry/wet fouled. I've found that the gaps are always within the manual-specified tolerances says so I never bother checking the gaps.
 
#22 ·
If you can see the timing light flashing consistently there is a good chance that side of the system is ok, you did say sort of though? How old are the spark plugs, are they heavily fuel fouled?

If originality is a concern then 66 models were fitted with twin 389/95 Monobloc carbs.

Rod
 
#24 ·
Have you tried eliminating all the main loom wiring and switches - just temporary wire the boyer direct from the battery and just the minimum wires you need to coils / pickup etc - don't use any of the wiring you already have -- could be bad wires / connections / intermittent switch fault
 
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