Reply
 
Thread Tools Search this Thread
 
Old 02 March 2012, 17:16   #1
Member
 
Country: UK - England
Town: Northampton
Make: RibTec
Length: 5m +
Engine: Outbaord mariner 75
Join Date: Apr 2011
Posts: 506
Odd 2 stroke issue

Hi,
Well started the old thing up again today and still noticing plug 3 is clean as a whistle while plus 1 and 2 are as they should be a little oily and sooty.

I am wondering if there is an issue with the reeds or card on cyl 3.

seems to run very nicley and revs freely with no lag or lumpyness.

Any Ideas??

ENGINE= Mariner 75 ELPTO 1991 2 stroke 3 carb.
__________________

__________________
jezza2011 is offline   Reply With Quote
Old 03 March 2012, 03:33   #2
Member
 
Country: UK - England
Town: Surrey
Boat name: Seaing Red
Make: Larson
Length: 6m +
Engine: Yamaha 140hp V4
Join Date: Mar 2012
Posts: 38
Hi Jezza,

If it was the reeds I would expect some blow back through the carb i think, and it probably wouldn't run all that well. Have you tried pulling the lead on 3 and comparing the running of the engine when you pull 1 or 2? Compression test? Do you mix the oil in the tank or is it injected?

Questions questions questions

SR
__________________

__________________
SeaingRed is offline   Reply With Quote
Old 03 March 2012, 04:21   #3
Member
 
Country: UK - England
Town: bicester
Length: no boat
Engine: outboard only
Join Date: Feb 2009
Posts: 894
remove the No 3 plug and have a good look at it and dont wipe it before you look at it ,does it glisten in the light? if so it could be the piston has picked up in the bore, now swop spark plugs to see if fault moves with the plug ,it doesnt move check to make sure the mixture screw hasnt screwed its self in, screw in until lightly seated then out for one and a half turns , is the throttles on the carbs still sycronized?remove the drain plug in the btm carb any crap come out if so remove carb and clean,you have to find out weather the fault is electric or fuel if it is electric i would also remove clean refit all earth wires, but it sounds more of a fuel problem, that lot should keep you out of mischief for a whill.
__________________
uncle al is offline   Reply With Quote
Old 03 March 2012, 06:57   #4
Member
 
Country: UK - England
Town: Northampton
Make: RibTec
Length: 5m +
Engine: Outbaord mariner 75
Join Date: Apr 2011
Posts: 506
SR: oil injected and all seems well there. Not compression tested but starts first time every time and runs well out so think the compression is ok.
Not checked for blow back. but if a reed is stuck would it not get any fuel and run like a dog and have starting issues?

Uncle Al: plugs swapped still the same. yep does have a slight sheen on it as if it were getting fule/oil
If it picked up wouldnt it be ripping itself appart?
checked the mixture screws and all seem ok.
All clean when drains removed.
Sparks checked and on no3 its sparking properly.

How am I going to tell if its picked up without taking the head off?
not sure if the carbs are synced properly. its been a whiles since its been serviced as there doesnt seem to be anyone locally.
__________________
jezza2011 is offline   Reply With Quote
Old 03 March 2012, 07:39   #5
Member
 
Country: UK - England
Town: Surrey
Boat name: Seaing Red
Make: Larson
Length: 6m +
Engine: Yamaha 140hp V4
Join Date: Mar 2012
Posts: 38
Ok, you say it's not been serviced in a while, I would definately start with a compression test, because its easy to do and can tell you alot. If thats all good then strip clean and adjust all carbs using the right rebuild kits. Then you'll be at a good starting point to diagnose further if it hasn't cured the problem.
But if you say it starts and runs ok, then needing a good service may be all the problem is!

If a cylinder has picked up then it's likely that the engine would run rough especially at idle. Compression test will tell you if theres a problem.

SR
__________________
SeaingRed is offline   Reply With Quote
Old 03 March 2012, 07:47   #6
Member
 
Country: UK - England
Town: Northampton
Make: RibTec
Length: 5m +
Engine: Outbaord mariner 75
Join Date: Apr 2011
Posts: 506
Hi SR, just checked and no3 is clean as a whistle. Hmm.
carbs look clean and the jet looks ok. just adjusted no3 as per the manual. 1 1/2 turns out.
But is been some time since its had a service so could be the carbs out..
mau try put a vid on here.
__________________
jezza2011 is offline   Reply With Quote
Old 03 March 2012, 09:58   #7
Member
 
Country: UK - England
Town: bicester
Length: no boat
Engine: outboard only
Join Date: Feb 2009
Posts: 894
as it is sometime since it had a service,this is what i would do,
remove strip and clean carburetors reassemble checking float hights
replace spark plugs
fit a fuel pump repare kit
replace fuel filter on the power head
i see you are on the site i will wait here for a while for a reply
__________________
uncle al is offline   Reply With Quote
Old 03 March 2012, 10:33   #8
Member
 
Country: UK - England
Town: Northampton
Make: RibTec
Length: 5m +
Engine: Outbaord mariner 75
Join Date: Apr 2011
Posts: 506
__________________
jezza2011 is offline   Reply With Quote
Old 03 March 2012, 10:34   #9
Member
 
Country: UK - England
Town: Northampton
Make: RibTec
Length: 5m +
Engine: Outbaord mariner 75
Join Date: Apr 2011
Posts: 506
should be able to see and hear it running there
__________________
jezza2011 is offline   Reply With Quote
Old 03 March 2012, 10:34   #10
Member
 
Country: UK - England
Town: Northampton
Make: RibTec
Length: 5m +
Engine: Outbaord mariner 75
Join Date: Apr 2011
Posts: 506
http://s1163.photobucket.com/albums/...t=PICT0002.mp4
Or here
__________________

__________________
jezza2011 is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 Off





Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 04:24.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.