engine problem troubleshooting (and yes it's that farking EL250 )

Ok guys, time to roll your eyes and go "christ, is he still trying to fix that fucking thing?"

Before you read on, know that i am planning to take it to a mechanic to get them to
fix it, but i'd like to do as much as humanly possible prior to then.

I've gotten the camchain replaced, that wasnt much of a worry, i've adjusted the tappets
to spec (0.01 intake, 0.013 exhaust) and verified that i didnt totally screw up the engine
timing, even to the point of taking the rocker cover off *again* and verifying the markers
were in the right spots at #2 tdc.

Symptoms are
1) the bike is now a total bitch to start, as in i cant just get a quick flick on the starter motor
and away she goes, it requires some cranking to get it to pick up, and you hafta hold the
starter motor on for a good 6-7 seconds for the motor to "catch" enough to sustain enough
momentum on its own.

2) Idle, it doesnt like idling very much, and yes i've upped the idle temporarily to see if it'd
help the recalcitrant motor to work, so far not a lot of joy.

3) Sluggish, the motor revs no worries once it has warmed up, but the response is akin to
asking someone to talk with a mouthfull of cotton wool.

4) backfires like bloody anything.

anyone got any serious suggestions, and as i said, yes i am planning to take it to a mechanic
as i stated above, but that is at least a good month away, and i'd like to be able to at least
ride my bike to my new unit next weekend and not have to trailer the bike. so even if i could
just get a head start on solving the problems, i'd be rather happy,

Cheers,


Mike.S

 

The camchain will be a couple of teeth out.

Doug Cox.
Work to ride, Ride to work...

 

That's what i was hoping to hear, now the question is to figure out which way its out and by how many teeth

Mike.S

 

Yeah, could be. I thought he said he checked it, though.
Mike, did you check it? eg: when the _crank_ is at TDC,
are the cams in the right place according to their marks?

Other things which come to mind. 1: fuel, if you've had
it in bits for a while the fuel might have gone gummy
and stuffed the carbs, easily fixed by cleaning them
2: timing, if you've reassembled the ignition pickups /
whatever you can get in all sorts of trouble, and have
you made sure all the wires go where they're supposed to?

EL250 == GPX250 motor, right?

 

i swear i got it right, though i believe you were supposed to do the timing with the exhaust cam ->crank under a bitta tension,
that is what i did, #2tdc, intake & exh marks were totally level, but i am tempted to take the bastard apart again tomorrow
morning and dong some investigative surgery (*AGAIN*). the quantity of popping and difficulty in starting it definately lend
towards the exhaust (maybe intake?) being a tooth out.

I never touched the carbs, they worked great when it was together, im not about to muck with them. same goes for the
ignition picups, i only played with the bits under the rocker cover and under the clutch-cover (rhs engine cover), which
means i didnt touch the ignition bits, aside from the coil packs, but i know both cyl's were firing as their exhaust cyls were
both burning hot.

and yeah, el250 == gpx250 == zzr250 donk.

There was also a big heap of help in that a past owner of the bike used a funky white paint and dabbed the tdc points
as well as the right places on the cams.

i've got the manuals out and i am going nuts doing a bit of investigation.
i'll let you know how i fair.

Mike.S

 

Whichever way it's being pulled from, I presume, which would be the
exhaust side on your, yeah. I think.

How long's it been in pieces though?

I'd independently confirm that those marks are in the right places
first up. You'd be amazed how often things are marked wrong, and
the owner just remembers "it's one tooth past the first white mark ..."

Good luck

-----sharks

 

i swear i got it right, though i believe you were supposed to do

That's it exactly

I *NEVER* let things sit dissassembled for over a few hours while im working on
it, i always put it back together, that is with the exception of i left the rocker cover once,
but i covered it with an oily rag while i took a break from it for a couple days.

The white mark was dapped just next to what kawasaki stamped on the cam rotor
for a little bit of a hand with visibility. So i'll be suprised if it's wrong. However i may
get a mate to take a peek at it.

Mike.S

 

"sharkey" wrote

...."

Reminds me of my neighbour of a looong time ago. He had a Honda Dream
305 and fitted a new timing chain. The new chain has two shiny links
on it for timing ease. Unfortunately the link is one tooth out on all
the genuine Honda chains. Took a while to twig to that.

Theo

 

is that a typo or what you set the clearances to ???

inlet 0.08-0.13
exhaust 0.11-0.16

i reckon you have the cams outof whack , check em again

remember to only turn the crank the way it supposed to go , never backwards as this can skew your viewing of the alignment of the
cams

 

I've gotten the camchain replaced, that wasnt much of a worry, i've adjusted the tappets

hmm, well bugger me, i didnt realise that i'd made a typo, but it seems i had.
Make that 0.10 in and 0.13 ex

ok, will give em a once over and only go forward you say? that's what might have caused this
problem, it'd certainly explain it as i did back-and-forth a teeny bit to align it. Next time if i get too
far forward i'll just have to go-around again. but it'd certainly explain the cams going out maybe
5'-10' or so.

Mike.S

 

I have a set of gauges for doing plugs and another for doing tappets, and yes i saw the wink.

Mike.S

 

i reckon you have the cams outof whack , check em again

I havent taken it apart, but i think i have got the cams outta whack.
I just found some info on the forum, and apparently now im re-reading the pdf of the gpx manual, i had missed one step.

1) rotate crankshaft counter clockwise until it has 2T visible through the timing window.
2) rotate crank 90' clockwise
3) now set the inlet and exhaust markers..

Guess who managed to not notice step #2?

This will have fixed all my woes i am sure. but imagine it, running a engine with both the intake *AND* exhaust
90' off, was a wonder it turned over by hand first, let alone run (and not kill anything internally).

Time to write "DUNCE" on the back of my helmet methinks.....

Mike.S

 

Fucking hell, colour me amazed. I thought you'd be picking
bits of valve up for doing that! (I'd consider pulling the
heads and taking a look at the piston crowns for marks, though)

-----sharks

 

Ah good, I'm glad that the PDF manual has been of use to *somebody*! ;-)

Hey Nev, how many downloads have people made of it so far?


BTH

 

Before i started the bike, i manually turned the bike over to see if i encountered any
resistance and to see if anything felt a bit abnormal. That yielded no problems, so i
went and tried turning the engine over, and it worked.... Of sorts.

I now have the bike reassembled, and i suspect i've gotta clean the sparkplugs.
Yet another adventure in the path to rideableness. Hopefully i get her started tomorrow
maybe tonight if i can be bothered putting in the effort!!!

I am going to be checkin the plugs to make sure there's no bits of nuked metal on
the plugs or that they havent been smacked by anything that came from the pistons
or valves though... thats the least i can do.

Mike.S

 

i mean the timing was out by 90' in relation to the crant, i do know that the cams rotate at
50% of the engine speed, meaning it'd be about 45' out there.

In any case im gonna clean the valves woulda gone fecking CLOSE to the piston, but at no
point were they touching (i guess i woulda known about it a helluva lot earlier if they had touched.

Mike.S

 

BTW, thanks BT (tho' it hasn't been used yet)!

 

Hi;
um I'd try and recheck the valve clearances as 1 thou. is bloody hard
to get right on a used bike.
If you can crank the motor over by hand , listen for any air escaping
from the intake or exhaust .A leaky intake and it'll be hard to start and a
sticky or leaking exhaust will explain the backfiring .
Anyway see how that goes BTW 0.01 is bloody hard to get right some
times even for these so called fully qualified machanics so I set mine at
0.02 but no more than 0.03 its better to be a bit over than under as you'll
burn valves .
Cheers
neadles

 

If you're talking about 0.01 you're talking mm not thou. 0.01 mm is
0.004" a huge gap and very easy to set. Anyone who cannot set a valve
gap with stud and nut to within 0.005 mm needs to pay someone else to
do it for them.

Theo
Who sets his valves on a cold morning to 0.00mm, +0.003mm, -0.00mm.
Piece of cake.