blackmax 200hp 1989 problems

[johno77]

Hi,
I am having problems with my mercury 200HP.1989 not 1998
I redid the carbys 2 years ago. The engine has been sitting. I took it out a few weeks ago. I put in fresh fuel and some sea foam. I ran it on the muffs a few times during the week before heading out. Most of the carbon was gone. Not much smoke. Engine ran ok. Little bit hard to start now and then. Went skiing for a couple of hours. Seemed to be good and all rpm.
Sat for a week. When I went to start it again, it would backfire and hard to start. Tried over a few days. Did a sync and link and adjusted idle best I could to workshop manual. When it did go, one of the muffs sounded like it was firing on 5. I noticed the tacometer would go anywhere from 2 - 5 and be erratic / not consistent. I put a timing light on all plugs but did not check the timing. i just wanted to see the consistency of the light. Consistent on all bar 5. It flickered slightly quicker and at one stage the light was just on with no flicker. Then it went back to flicker.
I swapped out switch boxes with other switch boxes I had spare. Engine still seemed like it was running on 5 and rpm tacometer was not consistent.

Do you guys think this could be the trigger or stator? Or idle stabiliser modules?
I've made a dva adaptor. Any tricks to using this?
Thank you

 

[Dukedog]

does it have tha 16 or 40 amp stuff on it?
a back fire usually involves timin' in some form or another.. erratic tach usually involves either rectifier and or regulator.. if its a 40 amp motor both will be in one unit... tha big water cooled thingy under tha coils.....

 

[johno77]

does it have tha 16 or 40 amp stuff on it?
a back fire usually involves timin' in some form or another.. erratic tach usually involves either rectifier and or regulator.. if its a 40 amp motor both will be in one unit... tha big water cooled thingy under tha coils.....

Thanks for the reply 16amp
Oh and its a 1989 model

 

[Dukedog]

yeah, '89 could be either one... if its still got tha idle stab. i'd chunk it... disconnect tha regulator jus for testin'.... i'd start with tha rectifier.. that "should" clear up tha tach problem.... ya need ta test stator and trigger.... back fire would lead me mostly to tha trigger... jmo.

 

[johno77]

yeah, '89 could be either one... if its still got tha idle stab. i'd chunk it... disconnect tha regulator jus for testin'.... i'd start with tha rectifier.. that "should" clear up tha tach problem.... ya need ta test stator and trigger.... back fire would lead me mostly to tha trigger... jmo.

okay slowly learning the regulator and rectifier are two different things yeah? I just haven't read about them yet in the book I have.
My workshop manual in some parts bit hard to understand its fallen to bits.Is the idle stabilizer on top or on the port side? There's two black boxes that look the same.

 

[Dukedog]

tha stab. will have red/white and a black/white wires.. tha rectifier will have 2 yellows, 1 red and 1 gray (tach signal wire).. how many and what color are tha wires comin' outta tha other box

 

[johno77]

tha stab. will have red/white and a black/white wires.. tha rectifier will have 2 yellows, 1 red and 1 gray (tach signal wire).. how many and what color are tha wires comin' outta tha other box

I get confused easy haha. Ill send a video link hopefully tomorrow .

 

[QBhoy]

Think you have sound advice above there. I’d certainly be looking around the main fuse and its holder. I’d also never rule out the carbs either. Despite being cleaned not long ago. Doesn’t mean anything, if there is any doubt around fuel sitting dormant in there for a while.
Learned enough to also never rule out the simple things, like plugs, battery connectors and earths being suspect. Battery too even and any isolators in line.
I take it the oil injection system has been done away with long ago ? Maybe do a compression test to rule out anything nasty. Not likely the case here..she would still start and likely run with no load, if the figures were low..outwith the most serious of situations.

Back to simple things again…fuel line going the right way and not drawing air somewhere? Fitting at each end ok ? Proven the delivery of fuel to the carbs by cracking a drain on the bowls and priming through ? If there is compromised fuel in there and it’s not firing up…the fresh fuel won’t show its face far enough to have an effect for the better. The old fuel could be the cause. Prime the carbs through and see how she’s goes.

That’s what I’d be doing first. Failing a result, time for the more intrusive with the multi meter

 

[johno77]

I did some more testing, dva tested trigger, stator ,coils and packs. All tested good apart from trigger low voltage 2.2v.I then removed idle/stabilizer wires and voltage came back up to spec on trigger.
I also did this test(not in the merc manual I have). Hopefully I worded it correct.

I indexed the flywheel placed numbers 1-6 on the flywheel. I placed timing light starting on 1 working my way to six.1-4fine showed up with timing light number 6 was also fine. But On number 5 it showed numbers 3,5and1.
I would assume this is a trigger problem would I be correct?
Engine smokes a lot and backfires on start up. Top of number
5 piston is cleaner then all the rest. I'm guessing because of the erratic timing on 5 it would be backfiring on 5 would I be correct in saying this. Any help much appreciated.

 

[Dukedog]

one thing you can do since you suspect #5.. swap tha switch boxes around.. if it stays tha same then it leads to tha trigger.. if it follows then ya have a switch box problem....

 

[johno77]

one thing you can do since you suspect #5.. swap tha switch boxes around.. if it stays tha same then it leads to tha trigger.. if it follows then ya have a switch box problem....

does that involve all the wires including the wires that go to the coils?

 

[Dukedog]

yes.. move ALL wires from the inside box to the outside box and ALL wires from outside box to tha inside..... this is just at tha switch boxes only....

 

[QBhoy]

I’d maybe guess that you’re getting some sort of cross firing. I’d maybe look towards testing across a few places with a meter. Look for continuity where there shouldn’t be and continuity where there should.
I might even be tempted to get her in a shed or garage…or under cover, turn the lights out/or in the dark of night…open the switch box and run her up. Look for any sparking or shorting out around and in the box. Around the leads etc etc too.

 

[johno77]

I’d maybe guess that you’re getting some sort of cross firing. I’d maybe look towards testing across a few places with a meter. Look for continuity where there shouldn’t be and continuity where there should.
I might even be tempted to get her in a shed or garage…or under cover, turn the lights out/or in the dark of night…open the switch box and run her up. Look for any sparking or shorting out around and in the box. Around the leads etc etc too.

Thanks Good idea

 

[johno77]

yes.. move ALL wires from the inside box to the outside box and ALL wires from outside box to tha inside..... this is just at tha switch boxes only....

cheers

 

[johno77]

Just wondering is there supposed to be continuity between the black ground to red/white? their also continuity from black to single red on the stator

 

[QBhoy]

Just wondering is there supposed to be continuity between the black ground to red/white? their also continuity from black to single red on the stator

I’d say it’s more important that you don’t have continuity between ground and each of the three stator wires. Should be open circuit there. Testing between each of the three wires to each other, will show continuity I’d think. Unless your set up is different to what I’m familiar with. What exactly do you have from the stator ? 3 wires ? Of what colour ?

 

[johno77]

I’d say it’s more important that you don’t have continuity between ground and each of the three stator wires. Should be open circuit there. Testing between each of the three wires to each other, will show continuity I’d think. Unless your set up is different to what I’m familiar with. What exactly do you have from the stator ? 3 wires ? Of what colour ?

, two blue ,two red, two yellow and one black

 

[johno77]

Hi Guys thanks for both your help. Hopefully you see this message. Its been about 7months since working on the motor.
My memory is hasie and I think i may have documented a video Of the last problem on had on the engine. (Well I hope I did a video)that will help me.

Okay so what I can remember from last looking at motor is I ended up getting a new trigger. I tested with new trigger engine still ran a bit rough.(i cant remember how rough).I Tested with the home made dva tester it passed all tests and also tested with like metioned before when i indexed the flywheel i retested with timeing light and was firing as it should instead of the problem I had before on number 5cylinder showing numbers 3 5 and 1 it just showed number 5.So i belive I fixed one problem.Excuse my grammer and spelling it late here but need to get this motor stuff of my mind and know help is nearby thanks guys.
I think start ups it still backfire or i could be wrong Ill have to wait and see when i get it back together.I do remeber lastly I thought id test compression agin and all where within spec 122,120,lowest was 119 (maybey lol)I though well thats a good sign.I figure i best do spark plugs up with torque wrench and do to speck at this point i think i cross threaded the sparkplug hole thread (probably dark and tired)I though great another problem I have to fix.So i took the cylinder head off now i found it interesting that one cylinder was particular shining so i took other cylinder head of well i think i did lol.I shall have to have a look when it coold down here in ausie land.Looking at the clyinder head i was supprised to find that it had where marks from looked like a ring had caught at some stage and hit the top of the cylinder head.Im pretty sure that someone had it apart before and just put the head back on.Looking inside the cylinder there was one mark i could catch with finger nail.Yet compression was within speck.
I then noticed that at a top of one of the pistons there was what looked like water droplets so im guessing this is causing some problems.
So questions are how do i track down to find where the water is coming from?
And would it be okay to use the cylinder head with the marks in the squish band?
If gaskets look okay can i reuse them?if so should I use a locktite on the gasket.I suppose what im thinking is i dont want to put new cylinder head gaskets on if i cant find the problem.
Okay thats it for now iv rambled enough.