Force 125 lacking power

[125]

Hi I regasketed them with the modified quicksilver one and done starting fluid test around them has no effect now with the new gaskets but still have no2 not firing put on new coil and moved cyl to cylinder as I say as soon as parts come I will put back together was wondering whether to first put back with old head gasket and sealer as if I put new gasket straight on and it has to come apart again I’ve junked a new head gasket that £100 pounds here in uk

 

[jerryjerry05]

Just use the old gasket and seal with silicone.
Then do a comp test after the gaskets been
reused.
When you install the new gasket, do a comp test
to see if the readings are all the same?
It won't hurt the gasket until the motor gets hot
and melts the sealer on the gasket.

 

[Redbarron%%]

Seal that "New" used head gasket with Hylomar blue and not silicone RTV.
The Hylomar will seal and be reused. I have done it fairly often with no problems.

 

[125]

Thanks just didn’t want to waste new head gasket if it ends up being pulled apart again and I’m pretty convinced it will as everything I have looked at has had a fault but not cured problem. But nothing wrong with head head gasket but happy it got taken off as pretty bunged up around cooling galleries. More ideas please throw them out there thanks

 

[125]

So got to spend more time on motor yesterday my focus has all been on no 2 cyl.had resigned myself that was putting back together without finding anything.started cleaning water galleries threads etc. Giving bores a wipe etc.no 1 cyl when piston is in line with exhaust ports the second ring on piston has a gap right in the port looked at all others and ring goes right around port.dont think ring can of broken as no marks anywhere so I’m guessing ring has moved off of how it is supposed to be retained.but as I have no loss of compression no no1 cyl issue could this in any way cause issue on no 2 by having a gap on no1 in line with exhaust port heeelp .?im hoping it could or I have found yet another problem with this engine but not the cause of my issue. So far recirc valves not suck and blow.sparks that don’t jump rec gap coils and cdi units.transfer port cover gaskets leaking air fuel pump gasket and another diaphragm leaking air.head off my idea in case was a blow thru.exhaust plate off as found so much debris in head thought prudent.happy found all these problems but miffed each time goes back together still has original fault.once it’s sorted should feel like it’s a 200hp for all bits that were at fault

 

[The Force power]

Thanks just didn’t want to waste new head gasket if it ends up being pulled apart again and I’m pretty convinced it will as everything I have looked at has had a fault but not cured problem. But nothing wrong with head head gasket but happy it got taken off as pretty bunged up around cooling galleries. More ideas please throw them out there thanks

Like Redbarron%% said; re-seal head gasket with Hylomar blue silicon ( a word of caution) APPLY only a thin film of it but too much will result into a gap between the cylinder & cooling passage. this will result in low compression and steam-cleaning

 

[The Force power]

Once it’s sorted should feel like it’s a 200hp for all bits that were at fault

I've seen on this form someone mentioning that the 90 hp was really "a tweaked" 85 hp & the 125 really a 120 hp Having said this I only know the 85 & 90 hp motors

 

[jerryjerry05]

How big is the gap on the ring?
Normally .006 to .016 is the end gap.

 

[125]

I will take a photo of ring gap tomorrow just seems strange to have gap in line with port when no other pistons do.?.

 

[Redbarron%%]

The ring gap should have a small pin aligning them in the notch on the ID at the ring gap. At least on the later model engines.

 

[125]

Just question would the ring gap be in line with port holes I was thinking with how much solid bore there was it shouldn’t be in line with port and as I say none of the other 3cylinders are.and my other question was if as I’m thinking this is wrong and what I remember seeing is a much bigger gap than being told could no1 gap in second ring in line with exhaust port cause engine to have a problem on no2 cyl thanks again all

 

[jerryjerry05]

IF??? the ring gap was at the port cover, it would be there on all
4 pistons, you can break and loose the ring without doing damage
to the cylinder walls.
IF?? the gap is bigger than 1/8th.in. your missing part of the ring???
All Force pistons I've ever worked on has the locating pin(Redbarron)

You check for damage on the piston skirt?

 

[pnwboat]

Maybe the ring gap you're seeing is actually a broken ring?

 

[125]

Didn’t get to boat today I’ve spoken to a few motor cross people today ie 2stroke people and they say.2nd ring plays no part other than be a guide and support for piston unlike 4stroke where bottom ring is scraper oil ring they also said to get motors to rev they take out 2 ring pistons and fit singles.so looks like I’m putting back together and starting over unless anyone comes up with anything beforehand to look at thanks Dave

 

[jerryjerry05]

Good luck.
A broken ring is still a problem. A broken ring is floating
in the groove and can start scoring the walls, maybe you
found it before it got ugly?
It seems you've done everything and found a
problem.
I wouldn't disregard this.
You check the skirt like I suggested?
If the bottom ring is broken, maybe the top's bad too?

 

[125]

So I will pull the pistons hone and re ring.but that ring is on no1 cyl.my non firing cyl is no2 so looking like. I’m doing some more work and money but if it needs it so be it but still not at point of finding misfire fault

 

[125]

At least I will know my motor intimately inside and out any tips on the ring and hone job ?

 

[jerryjerry05]

Take pics(lots) and find the shop FIRST!!
Not all machine shops can do an outboard
block.