Help & FAQs    Search BCF    Members    Groups    Events Calendar
Resend my activation email : Register : Log in 
BCF: Bike Chat Forums


Bike starts but wont idle, cuts out when not on choke?

 Reply to topic
Bike Chat Forums Index -> The Workshop
View previous topic : View next topic  
Author Message

Whosthedaddy
Super Spammer



Joined: 11 Dec 2005
Karma :
PostPosted: 14:15 - 28 May 2010    Post subject: Bike starts but wont idle, cuts out when not on choke? Reply with quote
The TRX will start from cold with just a flick of a switch but no sooner started have the revs dropped and cuts out.

If I start with choke then again, fires into action but this time the revs stay at just under 1000 revs / min. A few minutes on the sidestand or even down the road at idle, the revs remain lower than the 'warmed' up idle and have cut out again if not gently blipped.

After a few more miles, no problems, idle at 1,250+ revs.

This is summer? No real problems during the winter as always started on choke, but come on, I shouldn't be needing choke now to this extent?



Its a standard bike with standard cans, service was done a few 1000 miles ago.
____________________
Current : MSX 125 Past : CBR 900RR Monkeybike : c50 LAC : ZXR750 H2 : FZR600 : ZX7R P3 : YW100 : TRX850: Trophy 900 T309 : GSXR 600 L0: Monkeybike : XJ6S Whosthedaddy
 Back to top
View user's profile Send private message You must be logged in to rate posts

Crafty
Derestricted Danger



Joined: 24 May 2010
Karma :
PostPosted: 15:13 - 28 May 2010    Post subject: Re: Bike starts but wont idle, cuts out when not on choke? Reply with quote
[quote="Whosthedaddy"] but come on, I shouldn't be needing choke now to this extent?



Clealy the engine is saying it does need choke then.
Have you tried starting it on full (or even 1/2) choke & then reducing it to so the engine idles @1500rpm once its running?
Unfotunatly the electronic fuel injection systems have ruined the art of knowing how to start an engine the old skool way Crying or Very sad
____________________
To FINNISH 1ST, 1ST you gotta FINNISH.
Fastest is the 1ST to CROSS the FINNISH LINE.
2ND, IS the 1ST of all the LOSERS.
 Back to top
View user's profile Send private message You must be logged in to rate posts

Jesta_ZX6R
Borekit Bruiser



Joined: 23 May 2010
Karma :
PostPosted: 15:59 - 30 May 2010    Post subject: Re: Bike starts but wont idle, cuts out when not on choke? Reply with quote
Crafty wrote:

Unfotunatly the electronic fuel injection systems have ruined the art of knowing how to start an engine the old skool way Crying or Very sad


Agreed.

Have you checked the possibility of the usual suspects, ie clogged jets and float heights? If an engine is lean it will run better once hot, if an engine is rich it will run worse when hot, so it sounds like its very lean IMO

Once warm, can it hold revs around 9k for a mile or so, if not it could be fuel starvation, which usually boils down to a kinked fuel pipe
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

temeluchus
World Chat Champion



Joined: 01 Oct 2008
Karma :
PostPosted: 16:15 - 30 May 2010    Post subject: Reply with quote
Yeah make sure its all clean. Factories also often specify leanish settings stock. Try turning out your idle mixture screws a 1/4-1/2 turn.
____________________
Some shite cruiser. Now with guns and FREEDOM!
 Back to top
View user's profile Send private message Visit poster's website You must be logged in to rate posts

Whosthedaddy
Super Spammer



Joined: 11 Dec 2005
Karma :
PostPosted: 22:42 - 31 May 2010    Post subject: Re: Bike starts but wont idle, cuts out when not on choke? Reply with quote
Jesta_ZX6R wrote:
Once warm, can it hold revs around 9k for a mile or so, if not it could be fuel starvation, which usually boils down to a kinked fuel pipe


Nope, it cannot hold 9k revs as being the TRX and a twin maxes out at 8.
____________________
Current : MSX 125 Past : CBR 900RR Monkeybike : c50 LAC : ZXR750 H2 : FZR600 : ZX7R P3 : YW100 : TRX850: Trophy 900 T309 : GSXR 600 L0: Monkeybike : XJ6S Whosthedaddy
 Back to top
View user's profile Send private message You must be logged in to rate posts

Jesta_ZX6R
Borekit Bruiser



Joined: 23 May 2010
Karma :
PostPosted: 23:21 - 31 May 2010    Post subject: Re: Bike starts but wont idle, cuts out when not on choke? Reply with quote
Whosthedaddy wrote:


Nope, it cannot hold 9k revs as being the TRX and a twin maxes out at 8.


I see, the max RPM of your bike is not something I am familiar with and so you would have to improvise with a suitably high point in your rev range, perhaps 5-6k would be more appropriate as is the scenario of your bikes capabilities.

The purpose of what I am requesting is that as your rpm increases, as does your fuel consumption, if you have a blockage in the fuel delivery system then your bike will not be able to sustain a prolonged period at the rate of higher consumption. Which will be down to float height being set too low, a kinked fuel pipe or blocked fuel filter.

My money is on float or pilot.
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

molex
Renault 5 Driver



Joined: 07 Aug 2007
Karma :
PostPosted: 03:45 - 01 Jun 2010    Post subject: Reply with quote
For my experience "opinion" your TRX start air leak.!
better to check the joint between carburetor and engine
is it old enough to replace the parts.?

How to check air leak

https://www.mikuni.com/pdf/hsr_tuningmanual_021003.pdf

good luck.!
 Back to top
View user's profile Send private message You must be logged in to rate posts

Whosthedaddy
Super Spammer



Joined: 11 Dec 2005
Karma :
PostPosted: 07:41 - 01 Jun 2010    Post subject: Re: Bike starts but wont idle, cuts out when not on choke? Reply with quote
Jesta_ZX6R wrote:

The purpose of what I am requesting is that as your rpm increases, as does your fuel consumption, if you have a blockage in the fuel delivery system then your bike will not be able to sustain a prolonged period at the rate of higher consumption. Which will be down to float height being set too low, a kinked fuel pipe or blocked fuel filter.

My money is on float or pilot.


Oh no, the bike will more than happily pull and pull all the way towards a very long way past the NSL and quite comfortably stay there. Not that this is done on a regular basis Officer.

Very Happy

Will have a little nosy today for leaks.
____________________
Current : MSX 125 Past : CBR 900RR Monkeybike : c50 LAC : ZXR750 H2 : FZR600 : ZX7R P3 : YW100 : TRX850: Trophy 900 T309 : GSXR 600 L0: Monkeybike : XJ6S Whosthedaddy
 Back to top
View user's profile Send private message You must be logged in to rate posts

Jesta_ZX6R
Borekit Bruiser



Joined: 23 May 2010
Karma :
PostPosted: 07:47 - 01 Jun 2010    Post subject: Reply with quote
Thats a good point molex, I havent had one before myself, but it would also give the same symptons, you havent made any modifications to the airbox/filter have you?
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

molex
Renault 5 Driver



Joined: 07 Aug 2007
Karma :
PostPosted: 16:31 - 01 Jun 2010    Post subject: Reply with quote
My suggestion is tie up the pipe intake screw and clamp then test run.
 Back to top
View user's profile Send private message You must be logged in to rate posts
Old Thread Alert!

The last post was made 15 years, 268 days ago. Instead of replying here, would creating a new thread be more useful?
  Display posts from previous:   
This page may contain affiliate links, which means we may earn a small commission if a visitor clicks through and makes a purchase. By clicking on an affiliate link, you accept that third-party cookies will be set.

Post new topic   Reply to topic    Bike Chat Forums Index -> The Workshop All times are GMT
Page 1 of 1

 
 You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum

Read the Terms of Use! - Powered by phpBB © phpBB Group
 
Debug Mode: ON - Server: birks (www) - Page Generation Time: 0.10 Sec - Server Load: 1.24 - MySQL Queries: 13 - Page Size: 68.2 Kb