kick back when trying to pull start my 25hp

[bigscott]

Hi guys im hoping you can help.

I have a 25hp 2 stroke. When I try to pull start the engine I get about halfway and the flywheel just stops turning. I spoke to a guy over the weekend who reckons this is a common problem with older engines and theres nothing I can do about it apart from slowly pulling the pull start all the way out and trying again. IT happens a good few times before I get the engine going.


Any idea's?

OH forgot to say, the problem is become more common the more I use it

[PeterM]

Sounds sort of normal for pull starting. I have (I think) the same engine and it just needs a really good pull.

The modern motors have all sorts of fancy things to reduce the compression on pull starting but I think you are just feeling the cylinder compress as it comes up the stroke - just before they go 'pop' and the motor starts.

The solution is I think just pull harder......

I'm starting mine on Sat morning - if I remember I'll video it ...

[bigscott]

Aahh thanks for the quick reply PeterM its good news to know its not dying on me (hopefully)

It seems to happen regardless of how hard I pull so im going to buy a new pull cord and carry a backup just incase

[Ian M]

When I was first instructed in the noble art of swinging an engine, I was told to turn the engine until I felt it come up to compression (ie felt a resistance on the pull cord - you can experiment by pulling it past this point and see if the resistance suddenly reduces significantly; it has then gone past TDC) let the recoil mechanism recover the pull cord fully in, and then pull for all you are worth Sorry if I am instructing you in egg sucking

[bigscott]

sounds Good Ian So it could very well be down to my technique aswell ( don't tell the wife )

[Ian M]

we'll keep it to ourselves shall we?

[uncle al]

it sounds like it is the timming advancing ,it hurts like hell

[bigscott]

Yes it Does!!!! especially 2 or 3 times in a row. How would I go about changing the timming or is this a job best left to the experts

[uncle al]

just have the throttle in the tickover position then pull to start if it still does kick back you will have to find either a linkage fell of somewhere or it could be stuck/siezed in the advanced position, if it is electric advance the ecm may be faulty, tick over to fast ther you are something to keep you out of mischief good luck

[bigscott]

Cheers Uncle Al Ive had a quick look at the manual for checking and changing the timming. Lots of tinkering coming up

[9D280]

!!!!!!!!!!!! BE VERY CAREFUL WHEN MUCKING ABOUT WITH THE TIMING ON A 2-STROKE!!!!!!!

Thanks to the previous owner of my Merc I had a 3 pot rebore & 3 new pistons - if you advance the spark too far, when it starts there ends up being more fuel on the inlet side of the "piston dam" than the exhaust, which means when it sparks the bigger bang occurs on the inlet side and the piston is pushed sideways hard into the edge of the exhaust port..... The rest, as they say, is expensive.

Try the IanM approach first, and unless you really know what you are doing with spark settings, give it to a dealer!

I also guess it's a 2 cyl engine? They are very "lumpy" to pull generally. I manually started a Yam 55 2 cyl. It was like <brick wall> - <weeeee> - <brick wall> - <Wheeee> ... when pulled.

[uncle al]

you will require to check/adjust your timing,
1x timing light
1x rev counter
1x spark checker so you can remove the s/plugs and check the idle timing buy using the pull start
and the w/shop info to tell you what revs the timing should be (ie idle and wide open throttle)
dont just let the ht leads dangle in the air you could damage the stator

[Turbodiesel]

Im placing my bet on either, HT leads round the wrong way. Or Flywheel Keyway has broken and put the timing well out. See it loads of times on mariner 25's.

[bigscott]

Guys thanks for all the words of wisedom and help with this Ive decided that its out of my comfort zone and the engine will be going for a check up once Ive raised the cash.

The thought of me damaging the outboard by fiddling with the timing has basicly put the fear of god in me so best to leave it to the experts

[uncle al]

the definition of an expert is: ex is a has been , and a spurt is a drip under preasure beware of expurts sorry people