All of a sudden my 70 T120R won't even bark much less start - Triumph Forum: Triumph Rat Motorcycle Forums
Classic, Vintage & Veteran For Coventry and Meriden Models. Anything pre-Hinckley goes.

 3Likes
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 19 (permalink) Old 04-22-2019, 03:44 PM Thread Starter
SuperStock
Main Motorcycle: 70 Bonneville
Senior Member
 
Join Date: Sep 2011
Location: Folsom, CA
Posts: 223
Other Motorcycle: Norton Commando, OSSA MAR
All of a sudden my 70 T120R won't even bark much less start

My 1970 T120R was for the most part a one kick bike and ran well. Just as the good weather was ending I went to take it out and while it tried to catch a couple of times it was mostly non responsive. So I checked it for spark using the tool that goes between the lead and the plug and it showed to have spark on both cylinders. I replaced all of the fuel lines and filters just in case the filters were somehow plugged (even though they looked fine). I got real busy with lots of things and I am just now trying to start it with the new gas lines and filters. It has a months old high quality battery and lights the headlight bright (that stays on tender when not in use), an older Boyer ignition, and a newer electronic regulator.
When I kick it over (on the center stand so I can get the best kick) I get nothing. I was sort of waiting for warm weather so everything was going for me. It is in the low 80s today, but it doesn't even try to start. One more thing: late last Fall when it wouldn't start, after many kicks it would catch start to rev then immediately die. After those couple of short bursts, it has been totally non responsive.
Any help would be greatly appreciated. Jim
williekiote likes this.
yellow_cad is offline  
Sponsored Links
Advertisement
 
post #2 of 19 (permalink) Old 04-22-2019, 03:49 PM
Site Supporter
Commentator
Main Motorcycle: T140 E
Lifetime Premium
 
Join Date: Jun 2009
Location: Reading Berks UK
Posts: 9,230
Other Motorcycle: 56 Plunger Tatty Cub
Extra Motorcycle: CZ winter bike
Have you taken the plugs out and seen them spark? Are they wet?
Happyfeet likes this.
DAVE M is offline  
post #3 of 19 (permalink) Old 04-22-2019, 04:19 PM Thread Starter
SuperStock
Main Motorcycle: 70 Bonneville
Senior Member
 
Join Date: Sep 2011
Location: Folsom, CA
Posts: 223
Other Motorcycle: Norton Commando, OSSA MAR
Dave, I've only seen them spark with the linkage piece I mentioned (since I'm working alone) and the plugs seemed to be somewhat wet.

Since I first posted I kicked it another dozen times and it finally started and ran. I ran it just a bit, but it seemed fine. Since it doesn't idle until it is well warmed up, I let it die while I plugged in the fan I use to let it run in the garage. Now it was somewhat warmed up, but when I went to restart it, I got nothing again for a number of kicks.
yellow_cad is offline  
 
post #4 of 19 (permalink) Old 04-22-2019, 04:47 PM
SOTP Vintage Series
Main Motorcycle: 1971 t120r
Senior Member
 
rambo's Avatar
 
Join Date: Mar 2005
Location: exmouth devon uk
Posts: 6,950
Other Motorcycle: Triumph Rocket 111
Extra Motorcycle: Triumph Thunderbird LT
Garage
I was having a few starting problems. New plug caps fixed it. It did always start and run after a few kicks but much better for having new caps. The resistor was burnt out in one.

Now,where did that bit fall off ?
rambo is offline  
post #5 of 19 (permalink) Old 04-22-2019, 05:11 PM Thread Starter
SuperStock
Main Motorcycle: 70 Bonneville
Senior Member
 
Join Date: Sep 2011
Location: Folsom, CA
Posts: 223
Other Motorcycle: Norton Commando, OSSA MAR
Rambo, my spark plug leads are fairly new. Did your start problems with the bad caps sound like mine which is either it starts and runs (on a few occassions) or absolutely nothing (most of the kicks)?
yellow_cad is offline  
post #6 of 19 (permalink) Old 04-22-2019, 05:50 PM
Grand Prix 250
Main Motorcycle: 73 Tiger 750
Member
 
Join Date: Jul 2018
Location: Northern NSW Australia
Posts: 72
Other Motorcycle: Ducati ST3
Are you sure the plugs are getting wet?
I had a similar thing yesterday when I thought I was going for a ride today, so I went to start it to move to my other parking spot but no go.
When I pulled the plugs they were dry -ish , definitely not flooded as they should have been.
I had a weird issue at the end of the previous ride where it cut out completely a couple of times.
Although I took off the tank and checked the flow from the right side petcock it seems that is the culprit as when I turn on the left side I can hear the fuel filling the carb and then it starts easily.
I'm assuming there's an obstruction over that right petcock inside the tank so will investigate further and remove it and get a mirror in for a squiz.
Maybe you have obstructions on both sides, such as flakes of rust? Have you shone a torch and had a good look in there? Also the fine gauze filters on each petcock could have got blocked partially which would cause the bad behaviour.
Otherwise I'd be pulling the carb off for a good look and a clean. You could have a little bit of crap floating about that sometimes restricts or blocks a jet. Sounds very likely to me.

Last edited by Trumpkin; 04-22-2019 at 05:52 PM.
Trumpkin is offline  
post #7 of 19 (permalink) Old 04-22-2019, 06:03 PM Thread Starter
SuperStock
Main Motorcycle: 70 Bonneville
Senior Member
 
Join Date: Sep 2011
Location: Folsom, CA
Posts: 223
Other Motorcycle: Norton Commando, OSSA MAR
Quote:
Originally Posted by Trumpkin View Post
Are you sure the plugs are getting wet?
I had a similar thing yesterday when I thought I was going for a ride today, so I went to start it to move to my other parking spot but no go.
When I pulled the plugs they were dry -ish , definitely not flooded as they should have been.
I had a weird issue at the end of the previous ride where it cut out completely a couple of times.
Although I took off the tank and checked the flow from the right side petcock it seems that is the culprit as when I turn on the left side I can hear the fuel filling the carb and then it starts easily.
I'm assuming there's an obstruction over that right petcock inside the tank so will investigate further and remove it and get a mirror in for a squiz.
Maybe you have obstructions on both sides, such as flakes of rust? Have you shone a torch and had a good look in there? Also the fine gauze filters on each petcock could have got blocked partially which would cause the bad behaviour.
Otherwise I'd be pulling the carb off for a good look and a clean. You could have a little bit of crap floating about that sometimes restricts or blocks a jet. Sounds very likely to me.
Thanks Trumkin. I use two petcocks and tank if totally rust free. Also, I have two carbs. The few times lately that it has started and run, it seems to run fine, but just won't restart.
yellow_cad is offline  
post #8 of 19 (permalink) Old 04-22-2019, 06:04 PM
SOTP Vintage Series
Main Motorcycle: 1971 t120r
Senior Member
 
rambo's Avatar
 
Join Date: Mar 2005
Location: exmouth devon uk
Posts: 6,950
Other Motorcycle: Triumph Rocket 111
Extra Motorcycle: Triumph Thunderbird LT
Garage
With one of the resistors burnt out, the spark did get through at higher engine speeds so the engine ran fine. of course, at kick start speed, there was not enough energy produced to get over the fault. It was very lazy to get started and often started on one cylinder before the other cut in after running on one cylinder for a few seconds. It might be worth checking continuity on the caps. I now use caps with no resistors.

Now,where did that bit fall off ?
rambo is offline  
post #9 of 19 (permalink) Old 04-22-2019, 06:14 PM Thread Starter
SuperStock
Main Motorcycle: 70 Bonneville
Senior Member
 
Join Date: Sep 2011
Location: Folsom, CA
Posts: 223
Other Motorcycle: Norton Commando, OSSA MAR
Quote:
Originally Posted by rambo View Post
With one of the resistors burnt out, the spark did get through at higher engine speeds so the engine ran fine. of course, at kick start speed, there was not enough energy produced to get over the fault. It was very lazy to get started and often started on one cylinder before the other cut in after running on one cylinder for a few seconds. It might be worth checking continuity on the caps. I now use caps with no resistors.
I'm pretty sure that I have caps with no resistors.
yellow_cad is offline  
post #10 of 19 (permalink) Old 04-22-2019, 06:18 PM
Grand Prix 250
Main Motorcycle: 73 Tiger 750
Member
 
Join Date: Jul 2018
Location: Northern NSW Australia
Posts: 72
Other Motorcycle: Ducati ST3
You should have resistor caps with electronic ignition.
Have you checked the coil? The spark may not be as good as you think.

At least my other suggestions can be ruled out.
Trumpkin is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options
All posts must adhere to Forum Rules

Register Now



In order to be able to post messages on the Triumph Forum: Triumph Rat Motorcycle Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter your valid email address, that can receive an automated confirmation message. Otherwise, you won't be able to gain full access.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
start then click Collings Water Cooled Twins Technical Talk 22 04-30-2019 09:39 AM
No start when bike is hot Run Sprint Run Sprint Forum 4 04-29-2018 08:56 AM
1971 t120r won't start, help! Schrodinger Classic, Vintage & Veteran 23 08-29-2017 06:21 AM
02 955i need help/ wont start! mrclean826 Daytona Deliberations 10 12-17-2008 11:02 PM
Cold start, Backfire, Now won't start Alterna T3 Sport / Touring Forum 15 12-15-2008 01:48 AM

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome