Dead # 2 cylinder with good spark 1997 75hp 3 cyl. Force

leorupp

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Hello everybody , New to this forum thanks for letting me join. Here's what I have going on...I've been scrolling thru here for several days reading everybody's advice and tip's and suggestions on trouble shooting miss fires , rough idle , hard starts and so on...So after several days of trying all the good advice here's what I'm left with....1997 Force 3 cylinder , 75hp , ELPT serial # OE255798..with a dead #2 cylinder...I have 140# of compression in all three cylinders...I have spark ..(really GOOD spark) on all three cylinders..Here's what I've done so far ...while engine is running I pulled the plug wires one at a time , when I seen that pulling # 2 DID NOT change the way the motor ran I swapped coils to see if a different coil on #2 made a difference...It did not..So my question is where to next..? got fuel, got spark , got compression...I see a lot of suggestions with dead cylinders to change head gasket , which makes sense if you have low compression...or water in the cylinder..I don't have those issues....Thanks in advance..
 

GA_Boater

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Welcome aboard.

Is there unburned fuel on the dead cylinder? Since you have good spark on all three, have you tried swapping the spark plug with one of the good cylinders? Swap and pull the plug wire again.

Does this motor have 3 carbs?
 

Jiggz

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As mentioned, the next troubleshooting step is to verify fuel air mix is getting into the #2 cylinder. You can easily do this by checking the plug on #2. If there is sign of fuel wetting, then fuel is getting in. Then the next step is to dismount the carb and check the reed on #2.

If this is a single carb engine, reed is probably the cause of no fire on #2. If this has the 3 carbs, then check on the carb feeding #2 to make sure it is providing fuel. But if there is fuel wetting on the spark plug on #2 and still has no fire, then most likely the cause of your problem is you have broken reeds on #2.
 

leorupp

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Ok...so this is a 1 carb motor...I pulled the plugs when I noticed no change in engine when pulling plug wires...the #2 plug was wet but didn't look like it was firing ...swapped plugs after cleaning them , same result after running for a few minutes ...dead hole , wet plug...still looks like brand new...So being impatient like I am....I figured lets pull the head gasket just to see what the hell it looks like....no breaks or burnt areas or scores in the gasket...there was a very small amount of water in that cylinder .... the plug smells like gas...maybe the exhaust gaskets are bad...? I will pull the carb and check the reeds ...can you see them all thru the intake opening ...?
 

leorupp

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Ok I guess I shouldn't be so impatient...I pulled the intake off and low and behold there's a missing reed on the #2 cylinder...so I created a bunch of extra work for my self...you guy's really know your stuff...THANKS FOR THE HELP...needless to say before I pulled the intake I started to pull the exhaust plate...so I might as well change those too...So new head gasket ,new exhaust gaskets, new reed assembly...I better learn to be more Patient... Next big question WHERE DID THE REED GO TO...??? Looked all over in the cylinder and cant see anything...makes me a little nervous...Tried to upload a photo but the site wont let me...
 

GA_Boater

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You have three posts now, so the newbie post attachment restriction is met.

Click on Forum Help in the sig below and look at the tutorial about posting pics.

I don't know about your Force, but some 2 strokes have a removable reed block. The missing reed might be behind it.

After pulling up a parts diagram, it looks like your block does too.
reedblock.PNG


Remove the manifold #1, adapter plate #6 and the three reed blocks #8 are attached to the adapter. Maybe you got to this stage already.
 

leorupp

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Yep already ripped her apart...should've been a little more patient for a response though....now I have to change head gasket ,exhaust plate gasket and so on...any suggestions on getting the two bottom bolts out the exhaust plate ....very tight situation in there...I would skip that gasket but I've already broke them all loose ...
 

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GA_Boater

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You made more work for yourself, but hey, now you know where the bolts are.

I hope you are replacing all 12 reeds. One missing, one with a chunk gone and possibly others are damaged.

If the exhaust plate is still tight to the block, put the bolts back in and tighten them up. If the plate is coming away at the top, The gasket is damaged. The powerhead may need to be lifted to get to those bolts and more gaskets will be needed. Impatience may have cost you. :blue:
 

pnwboat

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To get to the lower exhaust plate bolts you might try unbolting the lower engine cover. Maybe 10 or 12 bolts. This will allow you to shift the lower cover away from the exhaust plate giving you a couple of inches of additional space.

Very common for the 1995 and later motors to break reed petals. Not sure why?
 

leorupp

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Thanks for all the advice...GA BOATER I'm gonna take your suggestion and retighten those exhaust plate bolts....the cover is still stuck to the powerhead...And yes I'm replacing all of the reed block assemblies ...pretty spendy items..$105 ea.
 

leorupp

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Does any one have any idea as to where the missing reed plate might have went.....?????:confused::confused::confused::confused:
 

jerryjerry05

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It probably went through the system and out the exhaust.
​If you haven't gotten the exhaust chest bolts out?? Just put them back in and be thankful you didn't break any.
 

Jiggz

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While the reed block is off, double check the crankcase cavity for it. Use inspection mirror to make sure it it not stuck anywhere including the intake ports. If you do not see it it's most likely went through the system out the exhaust already in pieces.
 

pnwboat

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I replaced my reed petals with some aftermarket composite ones. A complete set for your motor should run a little over $100. Some folks are have said that the composite don't last as long, but I've been using them for 6 years now and I recently looked at them and they looked as good as the day I installed them. Just another option.
 

leorupp

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pnwboat do have the part # for those and where you got them....My local shop wants a $ 105 for each set...that's $315 ...ouch !!!!!
 

pnwboat

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Boyesen reeds P/N B234.

There is a new set on Ebay for less than $90. Be aware that the B235 is for the 1992 and earlier motors that have reed petals that are rounded on the ends. The B234 are for the 1993 and later motors that have the squared off ends like yours.

One package of reeds replaces all of the reeds on the motor.
 

leorupp

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Thanks pnwboat...I orderd a set of those reeds...you saved me a couple of hundreds of dollars...My local boat shop wanted $466 and some change for all the parts I needed...Thanks to ebay and pnwboat, I got everything I needed for less than $180...!!!!! now just have to wait for it all to show up..:D
 

pnwboat

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Good luck with your "project". Wanted to mention to use some blue locktite on the screws that hold the reed petals in place and tighten them firm but don't crank on them as hard as you can. It will distort the reed petals if you over tighten them.

I thought about replacing the reed petals on my motor with the OEM factory replacements, but I've seen so many of the 1995 and later model motors with cracked, chipped or missing reed petals, plus the cost, I decided to go with the composite. So far I have not regretted my decision. I do check the reed petals every few years but so far they have worked great in my situation.
 
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leorupp

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Will do with the Loctite....I hear you on the price of the OEM reeds ....I figure if these composite ones go for even just 5 yrs. hopefully I will be able to upgrade the motor by then and if not well they were only $90...not $315
 
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