Triumph Rat Motorcycle Forums banner

1 - 20 of 29 Posts

·
Registered
Joined
·
70 Posts
Discussion Starter #1
Can't get my bike to start, its got a boyer EI fitted & the problem i'm having is when i can kick start it without it breaking my ankle ! it backfires & pops & thats about it, the guy i bought it from had a problem with its idle speed & he said they raised the needles in the carb & had it running fine, & then got the bike MOT'd !!

Any advice would be much appreciated.. Even my old harley 45 doesn't have anywhere near as much kickback as this one...
 

·
Registered
Joined
·
1,825 Posts
Kicking back usually indicates the timing is too advanced. Was the boyer set with a strobe? The static set up sometimes leaves them advanced. If it pops and backfires without starting, the leads from the rotor may need to be reversed. That would be the first thing I tried.
 

·
Registered
Joined
·
70 Posts
Discussion Starter #4
I don't know if they used a strobe light when fitting the boyer, I reckon it was probably fitted a couple of years ago. Do you mean the HT leads from the coils to the spark plugs ? If so do I just swap over the leads at the plugs ?

Sorry for my ignorance, not really very mechanically minded.

Paul.
 

·
Registered
Joined
·
70 Posts
Discussion Starter #6
will try changing over the leads & let you know the outcome, will also have a go at the timming, fingers crossed...
 

·
Registered
Joined
·
1,825 Posts
I was referring to the leads from the ignition stator. They would be connected to the terminal board that replaces the points plate. I wired up a Sparx EI on the Bitsa I built and had to the same symptoms until I reversed the leads. I kept moving the plate around and actually got it to run but it would still spit and pop and backfire and not run for more than a few seconds. After I switched the leads, it started first kick and would even idle. I dont think swapping sides with the plug wires will make any difference but you're welcome to try. I "THINK" the coils on a Boyer are in series and both fire together so it doesn't matter which lead goes where.
 

·
Registered
Joined
·
2,718 Posts
start

How old is the gas that's in it? Drain the float bowl and make sure there's no water in it. If the gas is old, put in the lawn mower and start over.
Got spark at both plugs? Spark should be blue/white. Starting ether or cabuerator cleaner will help isolate carb/ignition issues. One second spray in each carb, no throttle, kick all the way through to the bottom. They'll spit and kick when very lean. Smell any gas at the exhaust? Bob
 

·
Registered
Joined
·
2,718 Posts
wasted spark

You can get some serious kickback with a Boyer because both plugs fire every time. If the mixture does not ignite, another spark is coming at the wrong time and it may fire at the top of the exhaust. Bad/old gas may not ignite. A partially blocked passage leading to a lean mix may not ignite, then ignite later when gas accumulates in the chamber. Bob
 

·
Registered
Joined
·
1,228 Posts
Paul -
Let's start at the beginning.

• Sounds like you just acquired this bike. Have you ever heard this bike run?
• When was the last time it was taken out on the road?
• The number 1 issue with cranking Boyer bikes is a bad battery. What is the voltage measure of the battery when you follow the battery test on GABMA ?
• If the fuel is over 4 months old, put it in the family car and buy some new high-octane fuel
• Trying to crank with old fuel always fouls the plugs. Get some new NGK B7ES.

Give us a report on those topics, please.
 

·
Registered
Joined
·
70 Posts
Discussion Starter #11
Paul -
Let's start at the beginning.

• Sounds like you just acquired this bike. Have you ever heard this bike run?
• When was the last time it was taken out on the road?
• The number 1 issue with cranking Boyer bikes is a bad battery. What is the voltage measure of the battery when you follow the battery test on GABMA ?
• If the fuel is over 4 months old, put it in the family car and buy some new high-octane fuel
• Trying to crank with old fuel always fouls the plugs. Get some new NGK B7ES.

Give us a report on those topics, please.

1. Just had the bike a couple of days, when i originally viewed the bike 2 weeks ago it was running but the seller said it needed adjusting, which he was going to do before he took it for its MOT, i was due to collect it a couple of days later, turns out he got an auto electrician to look at it & he found a couple of dry points ? When i collected the bike I got him to show me the starting procedure & it started 1st kick, however i did notice that he kept his hand on the throttle, i commented on this and he said it just needed a good run.

2. The bike was used daily until last september.

3. When i got it home it took about 4/5 times to get it started, then it only got about 50yds down the road before it died.... After that it would not start.

4. I checked all the usual things I know, then put the battery on charge for 24 hrs, then checked all electrics working, checked for spark at both plugs & all ok..

5. All i get now when i try to start it is a very loud back fire & a kickback like nothing i've experienced before.

6. Fuel, as far as i know is fresh, but can easily change it.

I have ordered a new wiring loom as not really happy with the one thats there, seems to have been cut & joined in several places, but to be expected on an old bike, also noticed that the +VE earths are not going to a single point, so will need to rectify this i think !

The advice i've been given so far points to a problem with the ignition timing being too far advanced, which would definately explain the excessive kickback, but not sure about the seller telling me they lifted the needles or something in the carb to make it run ok ???

Would you recommend i replace the boyer EI as it seems to be quite an old one.

Have been told the ignition timming needs to be at 38' TDC for a boyer, is this an easy thing to do myself or do i need specialist tools etc...

Looking forward to any advice, Thanks, Paul.
 

·
Registered
Joined
·
1,228 Posts
Paul -
So you've never actually ridden the bike, as in 1 hour? That's bad. It could be anything causing your issues. Anything from "new owner lack of knowledge" to "very serious issues". We can summarily throw out all the PO told you as "sales hype".

OTOH.... Cold Triumphs don't idle very smoothly. I don't assign much to the hand on the throttle incident.

The Boyer is an excellent EI. It's been around 20 years or so and all the weak points are well known, understood and documented. (You can get some ideas from the ariticle on GABMA.) Most probably you won't get better with a new unit simply becasue all the "me too" EIs are all plagued with the same issues. Save your money for now.

The Boyer "box" is a plastic affair about the size of a pack of cigarettes ('fags' to Brits). Each one is marked with a small white tag with a date. If the unit is under 5 years old, Boyer will test or replace it free. Look for that.

Good wiring is critical to any EI. When you move from points ignition to EI, the transistors in the EI DEMAND that all the electrical connections be first rate, tight, correctly mated, etc, etc, just like you see inside your computer. If your computer wouldn't run with the bike's wiring, then a harness update might be mandatory.

The chief installation mistake is the return wire. Tell me what happens to the RED wire coming out of the Boyer box.

;)
 

·
Registered
Joined
·
70 Posts
Discussion Starter #14
The red wire from the boyer goes to the right hand side coil +ve terminal, after removing insulating tape to see where the wires are routed, there was a black/yellow wire from the boyer that had come lose from its connector ?

I suppose i was taking a chance on not riding the bike first, but have never been caught out before, but as they say there is always a 1st time !!

I have actually spoken to boyer electronics today as on closer inspection the top plate that connects where the points used to be is cracked & a piece about 1/2" is missing, so I have ordered a complete replacement EI from them, but i think maybe i will still have to re-do the timing.
 

·
Registered
Joined
·
70 Posts
Discussion Starter #15
paul,

you're in Surrey. Anywhere near Wrecclesham? (GU10 4QS)

try Rockerbox
01252 722973
Only about 10 mins away, can you recommend them ? Ideally would like to get it sorted myself 1st, but if I fail then maybe I can try them. Thanks.
 

·
Registered
Joined
·
1,228 Posts
The red wire from the boyer goes to the right hand side coil +ve terminal, after removing insulating tape to see where the wires are routed, there was a black/yellow wire from the boyer that had come lose from its connector ?
Well, there's 2 big problems right there...

• You unit has no power return. A quick check of the diagram shows it goes to the + coil side AND the RED wire within the harness. If you can't make it into the harness, then you need to add a wire all the way back to the base of the rectifier.

• The BLK/YEL is one of the "points" wires and makes a circuit to the Boyer magnet-coil setup. That wire and it's mate, the BLK/WHT must be plugged in and have excellent contact.

;)
 

·
Registered
Joined
·
70 Posts
Discussion Starter #18
Well, there's 2 big problems right there...

• You unit has no power return. A quick check of the diagram shows it goes to the + coil side AND the RED wire within the harness. If you can't make it into the harness, then you need to add a wire all the way back to the base of the rectifier.

• The BLK/YEL is one of the "points" wires and makes a circuit to the Boyer magnet-coil setup. That wire and it's mate, the BLK/WHT must be plugged in and have excellent contact.

;)
I'm pretty sure the connector on the 1st coil where the red wire from th EI goes is a double connector & there is another wire coming off that, so will check to see if that goes to the rectifier.

I have order a timing disc so that I can find the correct 38' BTDC so that I can re-sett the static timing & also have a strobe light so that I can time it correctly once running.

Will let you know how i get on.....fingers crossed !!!

Thanks for everyones input & advice, it is much appreciated. Paul.
 

·
Registered
Joined
·
1,228 Posts
I'm pretty sure the connector on the 1st coil where the red wire from th EI goes is a double connector & there is another wire coming off that, so will check to see if that goes to the rectifier.
On a 1969 with a stock harness the best place is then from the second + coil terminal over to the RED wire left over after removing the ignition condenser pack. That's an excellent harness return point.

I have order a timing disc so that I can find the correct 38' BTDC so that I can re-sett the static timing & also have a strobe light so that I can time it correctly once running.
There's nothing to buy. That function is already built into the 1969 engine behind the 3" window on the primary cover.


;)
 

·
Registered
Joined
·
1,131 Posts
The Boyer ignition box should never be covered with anything. It needs at least three side exposed to air flow for cooling!

The bike is not back firing because one plug is fired on the exhaust stroke. If this theory held water most modern cars would suffer the same symptom as they dual fire two cylinders, one on the exhaust stroke.

When installing a Boyer it doesn't matter which cylinder is under compression. They both fire at the same time. Verify that the timing mark on the motorcycle's rotor is 38° BTDC and align the pointer. Then align the white dot on the magnet with the clockwise hole and tighten the magnet and plate to the motorcycle.

If the timing plate wires are not connected properly it retards the timing about 30 degrees, and the bike will not start. It would be the same as if you located the magnet on a Triumph in the anti-rotation hole in the plate.

If the bike back fires it is either out of time (the magnet has come loose in the taper, the timing mark is not 38° BTDC or the white DOT is not aligned with the properly, or the carburetor is too lean.

Before you do anything be sure to clean the carburetor pilot jet. This can make it lean enough to kick back. Then really check everything, especially the timing mark on the alternator rotor and see if the magnetic rotor has come loose in the camshaft.
HTH
 
1 - 20 of 29 Posts
Top