Problems in starting the engine when hot

I've done some works on my Commando (including installing the TRISpark: by far better than my old Boyer). The bike starts immediately when cold, but for some strange reasons, tends to go off after a few miles; than it becomes very difficult to restart the engine. Any idea about how to solve this problem? Just let me add the the idle is perfect, and carburettors have been professionaly changed no more than three weeks ago.
R

Perhaps it's running out of fuel? Check the flow of your fuel lines.

I had the same problem with a trispark unit on my bike. Start fine, then cut out and very difficult to start. In the end she wouldnt even start when cold. I checked everything out and renewed alot of ignition parts, even down to rewiring. Still no go!!

In the end out of desparation I refitted the boyer unit and she went first time. I have just returned from tearing up the french roads with some mates, nearly 2000miles in a week, and she didnt miss a beat. To be fair to Steve Kelly I havn't returned the trispark to him for checking yet, but will do tomorrow. The symptoms seem familiar though.

gattomotore said:

I've done some works on my Commando (including installing the TRISpark: by far better than my old Boyer). The bike starts immediately when cold, but for some strange reasons, tends to go off after a few miles; than it becomes very difficult to restart the engine. Any idea about how to solve this problem? Just let me add the the idle is perfect, and carburettors have been professionaly changed no more than three weeks ago.
R

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Put the Boyer back on? At least if you still have the same problem you know it's not the Trispark.

When did this behavior start, after the Trispark? After the carbs were serviced? After any other work?

I have had nothing but good results from the Trispark but must admit that I have yet to put a lengthy run on the bike since I installed it. I keep the oem points/AAU handy and if the Trispark acts up, the points go back in with no more consideration on my part for an electronic ignition.

Mike, I can only report the same when i first fitted the trispark. It transformed her, idling was great, no problems in city traffic, great. But then after giving her a long, hot run things started to change. I will hold on my response til Steve gets the chance to check the unit out, but it all adds up one way to me...

I'm afraid you're right: I came back to the old Boyer. Same old problems, difficult to start, random idle, but no problems in starting when hot. I'll write tri-spark to try and solve the problem: perhaps I made some mistakes in installing it.

I purchased a Trispark, dual lead coil and resister plugs a couple weeks ago from Matt at CNW.
Installation was simple,with care taken to strobe the timing so 28-29 degrees showed at 3000 rpm with the timing light.

Just my opinion, but this setup is superior to my old boyar.
Bike starts with no kick back on one kick, idles cleanly and evenly, and runs the ignition advanced curve beautifully.
Very happy camper here with the trispark set up.

hey!
i don`t want to bring something new in this discussion although it isn`t the theme....

Got a pazon smart fire ignition with dual output coil [also had a boyer and changed to pazon cause of the well known reasons]:
i didn`t have any problems with fitting and setting the ignition, and my commando starts and runs very well.....also when battery is very low.

at the trispark system all the electrics are under the points cover? right? maybe it can`t handle with the heat at that point?
don`t know it...my thoughts....

chris

Hi Gattomotors/et all
It was upon reading these forums that I fitted a Tri-Spark, but now they appear to be held in a modicom of untested suspicion. However after a certain amount of tweaking around I love it. No more worrying about stalling at junctions etc.

I also replaced carbs and Tri-spark and a rewire at the same time, kept original coils. My personal experience is that it can be a bit awkward when engine hot, but careful timing plus closing the choke a little and giving it a bit of throttle,even when hot, its fine and never conks out or forces me to build up a sweat kicking it over.
When the Boyer was in situ I didnt have to open the throttle at all to get it going.
Of course we all know what works for one Commando may not/will not work for another machine. Hope you find a fix.

How about "insulation plates"between carburettors and cylinder head?.

"aries"]Hi Gattomotors/et all


giving it a bit of throttle,even when hot, its fine and never conks out or forces me to build up a sweat kicking it over.

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That can mean the carbs are a little rich, not that it matters in the scope things, hell it starts. :wink:

Cash

gattomotore said:

I've done some works on my Commando (including installing the TRISpark: by far better than my old Boyer). The bike starts immediately when cold, but for some strange reasons, tends to go off after a few miles; than it becomes very difficult to restart the engine. Any idea about how to solve this problem? Just let me add the the idle is perfect, and carburettors have been professionaly changed no more than three weeks ago.
R

Click to expand...

Checked the fuel tank cap is venting OK? That allows fuel to flow under normal air pressure. The simple test is run the bike until does what you have described. Open the tank cap and try restarting. It may also be a flow problem. Like the other guys said check the fuel flow. Try the tank completely full. With the cap shut, pull off both hoses and run both taps on into a bucket. Fuel should flow constantly at the same rate.

Check all manifold joints for tighness, thats a common cause when carbs have been refitted. When the motor warms up, the joint gap expands and you get a lextra ean mixture sucked in. Be carfull when tensioning the carbs to the manifolds, only torque them up a bit on each side to avoid warping flanges.

Mick