Suzuki2Strokes.com

Sundial Moto Sports

Suzuki Two-Stroke Message Board
Suzuki2Strokes.com
It is currently Thu Sep 20, 2018 9:39 am

All times are UTC - 6 hours




Post new topic Reply to topic  [ 29 posts ]  Go to page Previous  1, 2
Author Message
 Post subject: Re: Poor Running
PostPosted: Mon Sep 10, 2018 9:53 am 
Offline
Moto GP
User avatar

Joined: Mon Nov 03, 2008 10:47 am
Posts: 5981
Location: Illinois
Just an off the wall thought, but are both slides correct and in the same way?

It's not unusual for someone to fit slides in the wrong carbs so they face backwards, but if a PO replaced the slides, it may be that one is in backwards.


Top
 Profile  
 
 Post subject: Re: Poor Running
PostPosted: Mon Sep 10, 2018 12:47 pm 
Offline
On the street

Joined: Mon Dec 11, 2017 3:19 pm
Posts: 42
Country: United Kingdom
Bikes owned: T250 Hustler
Hello
I started it tonight with the airbox removed and when I placed my hand over the left hand carb there was no suction compared to the right one which tried to suck my hand in.

Any ideas what would cause this?

Paul


Top
 Profile  
 
 Post subject: Re: Poor Running
PostPosted: Mon Sep 10, 2018 1:39 pm 
Offline
To the on ramp

Joined: Tue Mar 10, 2015 12:35 pm
Posts: 402
Location: Wales
Country: WALES
Bikes owned: suzuki gt 550j
That could be very bad news I'm afraid. The most likely reason there is no suction is a bad crank seal which is an engine strip down. I would do a leak down test to confirm it if you can't perform this I would go to a good bike mechanic who has the equipment.

_________________
98 carb Blackbird and GT550j


Top
 Profile  
 
 Post subject: Re: Poor Running
PostPosted: Mon Sep 10, 2018 3:03 pm 
Offline
On the street

Joined: Mon Dec 11, 2017 3:19 pm
Posts: 42
Country: United Kingdom
Bikes owned: T250 Hustler
Hello
Could that be the outer seal ?

Thanks


Top
 Profile  
 
 Post subject: Re: Poor Running
PostPosted: Mon Sep 10, 2018 4:59 pm 
Offline
On the main road
User avatar

Joined: Mon Jun 12, 2017 12:01 pm
Posts: 165
Location: Galveston County, Tx.
Country: USA
Bikes owned: '75 T500M since '93 Ridden it over 100,000 mi
As a matter of orderly troubleshooting (we have kinda skipped that),would you please address the comments from members about the throttle valves (sliders). You can use a small mirror to look at them easier now that you have the air box off. Also, there is a rod for the sliders......I've read that they can be bent and cause problems......maybe even causing the slider to detach from throttle cable?

Here is a picture how they should be ......cutaway FACING air box. Turn the throttle grip and look if they are both entering (or one not moving at all) at the same exact time
https://m.ebay.com/itm/1972-Suzuki-T250 ... 4335.l8656"
......and you are getting a healthy stream of fuel from each outlet of the fuel petcock and lines are known clear.....correct?

Good Luck

_________________
______________
______________________
_______________________________
GONE.......WITH A PUFF OF SMOKE AND A BLUR OF SPOKE


Top
 Profile  
 
 Post subject: Re: Poor Running
PostPosted: Mon Sep 10, 2018 6:46 pm 
Offline
On the main road

Joined: Sat Sep 05, 2015 3:14 pm
Posts: 129
Location: southeast pa
Country: us
Bikes owned: GT
dorT500 wrote:
As a matter of orderly troubleshooting (we have kinda skipped that),would you please address the comments from members about the throttle valves (sliders)

+1 on that.
The carb slides must move together from idle to wide open throttle.
If the slides are at different positions, or incorrect, the vacuum will be at different levels.
dorT500 wrote:
Also, there is a rod for the sliders......I've read that they can be bent and cause problems

+1 on that also.
The idle rods bend easily and don't allow slides to drop all the way down in carb at idle, if one slide is higher than the other you will have an uneven running engine.
Your video makes me think your left carb slide is to high compared to the right slide.
You can also have trouble if carbs are over tightened, not allowing slides to move freely.
Your first post said the left cylinder was ok, right cylinder was intermittent, has the left cylinder now stopped firing?

_________________
76 GT185
77 GT250
77 GT380
76 GT500
73 GT550
73 GT750
74 GT750
71 T250 scrambler
75 T500 cafe


Top
 Profile  
 
 Post subject: Re: Poor Running
PostPosted: Tue Sep 11, 2018 12:55 pm 
Offline
On the street

Joined: Mon Dec 11, 2017 3:19 pm
Posts: 42
Country: United Kingdom
Bikes owned: T250 Hustler
Hello

Both slides seem to be lifting at the same time but I swapped the carbs over tonight and when it was running I placed my hand over each carb (one at a time) and it was sucking and it nearly stalled the engine. The other night when I tried placing my hand over the intake it was on the r/h side carb that was sucking but there was nothing from the left carb I have checked the carb tops and they are not over tightened

The r/h cylinder is still getting hot while the L/h one remains cold.

Does this point more to a carburettor problem? All the carb internals have been changed using new genuine parts except for the floats which seemed in good condition so I reused them.

Appreciate the advice

Paul


Top
 Profile  
 
 Post subject: Re: Poor Running
PostPosted: Tue Sep 11, 2018 2:20 pm 
Offline
To the on ramp

Joined: Fri Aug 11, 2017 7:09 am
Posts: 260
Country: england
Bikes owned: several gt250 ramairs
have you done anything off the list i advised earlier? namely, take the left crank drain plug out and see if it's full of mixture? if it is it won't run on that pot :(
let's get this right :D the cylinder with the choke carb on it is the one that's not firing? the left pot?
[1] take the drain plug out, empty if necessary, refit drain plug - tight.
[2] take the airbox off and stuff a rolled up CLEAN rag in the left carb inlet.
[3] hold throttle just open and kick her up, see if she now runs on both cylinders.
[4] don't whack the throttle open and let engine swallow the rag :D remove it and see if engine runs on 2 pots.
[5] if so, you're done, if not, remove left exhaust and see if it's full of mixture - it could be by now.
[6] follow ALL the good advice that everybody on here has posted for you - not just bits of it.
[7] we'll sort the little s o b eventually :D
cheers, dd.
ps, i've tried the rag in the carb many times, always after a rebuild. sometimes they need a little help just to get that first lung full through. after that it's first kick every time - but don't forget to remove the rag once she's running :D

_________________
GTS250 road registered. TS250 engine, Ramair frame.
GT250 big bang road registered. Both pistons fire the same time. USD forks.
GT285 road registered. Overbored - 58mm and TS125 +2 pistons fitted.
GT10 road registered. '65 T10 engine, GT250 frame.


Top
 Profile  
 
 Post subject: Re: Poor Running
PostPosted: Wed Sep 12, 2018 5:29 am 
Offline
On the street

Joined: Mon Dec 11, 2017 3:19 pm
Posts: 42
Country: United Kingdom
Bikes owned: T250 Hustler
Hello DD
In answer to your questions
A) it is the right hand cylinder as you sit on the bike which is not running correctly the choke liver is on the L/ H carb with a rod which connects to the right carb.
B) I have taken both drain plugs out and I did get some fuel mixed with oil but I did this again last night after I have been messing about trying to get it running properly and nothing came out.
C) I have had it running about 2500 rpm and you can see on the video it is smoking from the left cylinder and making a put put sound from the right side and there is no pressure out of the end of the exhaust
D) I swapped the carbs over and both carbs are sucking through the intake but when I change them back again the L/H one is not sucking air
E) I haven't removed the left exhaust yet

Thanks for the help because I'm floundering at the moment.

Regards
Paul


Top
 Profile  
 
 Post subject: Re: Poor Running
PostPosted: Wed Sep 12, 2018 8:19 am 
Offline
To the on ramp

Joined: Fri Aug 11, 2017 7:09 am
Posts: 260
Country: england
Bikes owned: several gt250 ramairs
hmm, strange that. the left side is working, but the left carb isn't sucking air? that doesn't make sense to me :o
you have the early carbs with the joined chokes? do they both open and close together properly?
do you have a fuel feed to each carb, or is there a tube from the left to the right carb? if so, is it blocked or kinked enough to stop fuel getting through?
double check everything. i've had this problem with newly rebuilt engines and every time it's been the right pot that didn't run [odd that], and 90% of the time it's been the ignition circuit, points, plug, coil, condensor etc. if you emptied both crank drains and there was mixture in both, then fuel is getting through. take the spark plugs out and turn the engine over on the kickstarter whilst watching the points. when one side closes, make absolutely sure it's properly closed. same with the other side. this is something simple that we've missed :D i've still got a few ideas left, but try those first :D
cheers, dd.

_________________
GTS250 road registered. TS250 engine, Ramair frame.
GT250 big bang road registered. Both pistons fire the same time. USD forks.
GT285 road registered. Overbored - 58mm and TS125 +2 pistons fitted.
GT10 road registered. '65 T10 engine, GT250 frame.


Top
 Profile  
 
 Post subject: Re: Poor Running
PostPosted: Wed Sep 12, 2018 9:44 am 
Offline
On the main road
User avatar

Joined: Mon Jun 12, 2017 12:01 pm
Posts: 165
Location: Galveston County, Tx.
Country: USA
Bikes owned: '75 T500M since '93 Ridden it over 100,000 mi
There is some type of communication problem going on here. Anyway, here we are, doubling back and starting where the trouble shooting should have started in the first place.....the battery(and yes, even if its brand new) , and ignition related parts.

I'm as guilty as the next guy that has not done an orderly troubleshooting procedure sometimes but overall, it is the way to save time and frustration.


Yes, he said he was getting spark at both cylinders... fat blue spark or weak yellowish spark, intermittent? We can get to a possibility that the right side carb has been distorted just a bit from uneven tightening at the flange but first we want to know that all is as it should be at least the ignition breaker points and adequate fuel flow.....both of these brought up by members early on but not addressed.

I'm doing this on my phone right now and it's kinda of a hassle doing it that way (details) but two things have been crossing my mind all along......that is the battery and the points gap adjustment at least on the rightside has slipped and the gap is down to next to nothing.

T250,T350 and T500 have been known to drop the rightside cylinder when there is a battery issue.

_________________
______________
______________________
_______________________________
GONE.......WITH A PUFF OF SMOKE AND A BLUR OF SPOKE


Top
 Profile  
 
 Post subject: Running At Last
PostPosted: Wed Sep 12, 2018 1:10 pm 
Offline
On the street

Joined: Mon Dec 11, 2017 3:19 pm
Posts: 42
Country: United Kingdom
Bikes owned: T250 Hustler
Hello
Thanks for all the advice swapped the carbs back onto their correct cylinders after swapping them to see if it made any difference I put my hand of each carb and they were sucking air well then a flame came out of the R/H carb and then the right cylinder chimed in.
Thank God For That

https://youtu.be/P-0akGpWkS4

Big thanks for all the advice :D


Top
 Profile  
 
 Post subject: Re: Poor Running
PostPosted: Wed Sep 12, 2018 1:34 pm 
Online
On the main road
User avatar

Joined: Mon Oct 24, 2016 12:35 pm
Posts: 114
Location: Macon, GA
Country: USA
Bikes owned: 76 GT750, 72 H2 750, 84 RZ350, 67 YR1, 82 MB5
Sounds good! So what fixed the issue?

_________________
1976 Suzuki GT750 (Maui Blue), 1972 Kawasaki H2 750 Mach IV (Candytone Blue), 1984 Yamaha RZ350 (KRR- Yellow/ Black), 1967 Yamaha YR1 (Red).


Top
 Profile  
 
 Post subject: Re: Poor Running
PostPosted: Wed Sep 12, 2018 2:47 pm 
Offline
On the street

Joined: Mon Dec 11, 2017 3:19 pm
Posts: 42
Country: United Kingdom
Bikes owned: T250 Hustler
Hello
I'm not sure whether there was something up with one of the carbs before I swapped them the R/H one was not sucking air but after putting them back onto the correct barrels they were both sucking air and then the cylinder stared firing correctly

Cheers
Paul


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 29 posts ]  Go to page Previous  1, 2

All times are UTC - 6 hours


Who is online

Users browsing this forum: Google [Bot] and 58 guests


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 post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group
Sundial Moto Sports forum © by Eric F. Kalamaja
Suzuki2Strokes.com