Force 125 lacking power

[125]

Thank you once again Jerry for taking time to read and advise hope to get another look later this week will report findings

 

[125]

Thanks jerry got a look today my engine has for covers behind coils stalls when I spray start fluid mainly on the one that has fuel pump mounted to it which is effectively no 3 and my worst cyl was no 2 but air can do funny things great help mate as before I removed coils with out your knowledge didn’t even know that these plates existed or their purpose I will report back as soon as I’ve regasketed all 4 don’t know how long for parts here uk thanks once again Jerry all the best Dave

 

[125]

Thanks jerry got a look today my engine has for covers behind coils stalls when I spray start fluid mainly on the one that has fuel pump mounted to it which is effectively no 3 and my worst cyl was no 2 but air can do funny things great help mate as before I removed coils with out your knowledge didn’t even know that these plates existed or their purpose I will report back as soon as I’ve regasketed all 4 don’t know how long for parts here uk thanks once again Jerry all the best Dave

Jerry is there any other parts in that area need replacing whilst doing as everything on the engine is 1989 apart from bits mentioned in previous posts any where else near here starting fluid would get drawn in thanks again

 

[racerone]

Sprayed starter fluid can get to the intake.-----Give you a warm fuzzy feeling and false impression.------Good idea to remove those bypass covers.----Will let you look at pistons and rings.

 

[jerryjerry05]

Usually any air leaks come from the port covers,
once in a while the gaskets under the carbs.
Things like electrical contacts need sanding, cleaning.
All the connectors on the trigger and stator, if I have
any question I replace them ALL.
Just be careful as the trigger wires are very thin and
can break when squeezing the end.

 

[125]

Jerry all my terminals all new cdi units new cfi by pass covers and gaskets new carbs cleaned gasketed set up link sync timing done fuel pipes filter separator new 4 good spark jumping big gap as per your suggestion start fluid sprayed onto transfer ports stopped the engine from the ports not getting into carbs as racerone suggested as if was case would get in carbs. When spraying other 3 ports so got to strip today none of the gaskets in great condition so will be ordering those thought while apart I would remove Reed assemblies some showing light some not couple have big gaps but all in good condition piston rings pistons all like brand new. Please advise been told I can simply turn reed petals over is that so. On assembly do gaskets go up dry or is sealer used. And lastly I brought this engine brand new in 1990 so 31 years old very low hours due to uk weather tides etc we are lucky if we get out 6 to 8 times a year for couple three hours at a time.but was going to ask your opinion on whilst stripped is it worth pulling off cylinder head for new gasket thanks once again for your time cheers Dave

 

[125]

Has always been maintained flushed and looked after like a baby by the way and apart from this hiccup now has never missed a beat plugs gear oil impellers and service is all the engine has required oh and couple of lower shock mounts wish I’d faired as well in 31 years

 

[jerryjerry05]

If it's been ran in salt water? then I'd think
about changing the head gasket.
The bolts might be hard to remove?? the
corrosion on the bolts can make it hard to
remove, take your time or you'll twist the
heads off the bolts.
If the reeds have minor gaps?? then they'll
be ok. They're designed to stop the gas from
going out and small gaps will close off when
running. If there's gas coming out the front
of the carb when running, then fix them.

 

[125]

Was the info I was given correct about being able to turn read petals over Jerry there are couple small areas where light shines through and two or three where you can actually see petal has quite a gap thanks

 

[racerone]

Install new reeds.

 

[Nordin]

Well as racerone says change the reed pedals, do not flip them over.
BTW: I gave you the advise of checking the reeds i #29 post.

 

[jerryjerry05]

Gaps???
.010-.020 ?? That's acceptable.

 

[125]

Ok so put motor back together.new transfer port cover gaskets modification ones with silicon bead.turned over reed petals as temp measure have ordered a carbon fibre set from the states ccms racing.re gasketed reeds housing carbs etc.fired up and is still miss firing no2 cylinder.so as I had said before I pulled the head.pulled the exhaust cover as well but found no evidence of blow by crossfire etc.but I could not believe the amount of crystallised crap in my motor that needs cleaning out and this motor always flushed after every use. But alas still no problem to be seen ref running. So order on Monday new gaskets should I have the head surfaced skimmed ? Bores pitons rings all look good the only thing is on no2 prison is a shiner round mark clean thru the carbon in line with spark plug and diameter of plug where as 1 3 4 have carbon over whole crown will try adding videos photos.as always all suggestions appreciated thanks in advance dave

 

[125]

So pictures are between 1 & 2 and video is no 2 bore and piston crown hopefully showing burn thru carbon I spoke about
View attachment D2ED8A8C-E6BA-4BA8-A6C4-72449C218D18.MOV

 

[125]

I am right out of ideas and depth now with uk season that lasts all of a few weeks if we are lucky fast approaching and each order I make up to a two week wait to get is there any point in pulling pistons while I’m this far in.is a head skim reface recommended how much off new carbon fibre reeds from USA ccms racing.head gasket. New stat and bits should all arrive approx same time.new exhaust port cover gasket and plate. One broken bolt in that to deal with all threads and bolts cleaned and lubed anything else while I’m waiting to do .?? Thanks all

 

[jerryjerry05]

Just one bolt??? Man did you get lucky!!!!
The exhaust plate: It's famous for breaking bolts
and being a real pain to reseal.
If possible try to get the surfaces milled so they
match up.
If not, use lots of sealer.

 

[125]

So did you have any more ideas jerry as I said pulled the head in the hope of finding fault on gasket. But nothing found.same pistons bores rings all looking good.so am going to put back together carbon fibre reeds new head gasket new exhaust plate all machined etc but pretty sure I’m still going to have no2. Not firing? Is it a possibility that it could be a trigger fault although there I a spark it not triggered at right time.or is it possible for the block to draw air on two halves had that on two stroke motor cycle once am I right to assume that a crank seal would not affect cyl 2 I’m really starting clutching at straws right now. Anyone with any fresh ideas

 

[jerryjerry05]

No spark on #2??
Try swapping the packs around and see if the
no spark moves to #4???
Try swapping the coils around?
The trigger leads are very thin and break under
the shrink wrap, tug on them and see if one's
loose??

 

[125]

I have run it with spark tester on sparking.i brought the adjustable spark jumper you recommended jumps great big gap. This is why was asking about drawing air on two halves of block or triggers.i took head off hoping to find a blow thru from. Cyl 2 to cyl1 or 2 to 3 not the case all good on head so now will put back together and try over but I have previously swapped packs 1 new cdi 1 new coil and swapped cyl to cyl always comes back no2 all new terminals on connections from cdi s flywheel etc

 

[jerryjerry05]

Try the starting fluid test around the port covers?
You say you swapped coils?