Aaarrrgggghhh!!!!!!!!!!

[VectorPat]

Well after finding the blown head gasket that I thought was causing my midrange miss, I put the new heads shaved .050 on instead of the .100 ones that were on there..That got my compression down to 135-140 instead of 155-160..Bumped the timing up to 25deg..And took it out and ran it..Well I lost 2mph and 200rpm now and still have the miss:mad: :mad: ..I went up higher with the jackplate and got my speed and rpm pretty much back but still have this miss..Someone had been cutting on the throttle cam so maybe thats what it is...It just sounds like its dropping a cylinder over 1500 to about 4500 after that its fine..I guess I`m going to have to get of the water and off my ass and build me a real motor for this thing..
Any other ideas guys:confused: :confused: ????Oh , its a 175, horz. reed motor by the way..

[Bruce Washburn]

I am not sure of everything you have checked so far but here are a couple of ideas.
1. Check the ferites on the coils for cracks. Pull the coils off, pull the rubber boots off the coils and look for visable cracks on the ferites. The cracks can make the engine less reponsive or seem like it has a miss.
2. Have you gone throught the carbs? Also check the reeds while you have the carbs off.
3. When you check the plugs is there one that looks much wetter or dryer than the others?
4. There are some electrical problems as simple as bad wires that could cause a miss or weak fire/miss. Also the bias circuit in the switch box can also cause serious problems including burning a cylinder. I have also seen stators make an engine run poorly but it does not sound like a stator.
I hope that this helps. Good luck
Bruce

[us1]

Bruce is probably right about it being the electrical. Put a timing light on each cylinder and rev it up past the miss RPM. Check to see if your spark is dropping out.

[VectorPat]

I have been thru the carbs and they are ok..It has 2 brand new switch boxs on it..They didnt change anything..All the plugs look the same...it only does it under a load..I`ll check the coils out and see what they look like..Thanks guys!!!!!

[VectorPat]

Pulled the coils off..3 of them cracked all the way through, this one the worse..I have acouple dead powerheads at work..Hopefully I can scavenge 3 coils off of them:D
thanks again Guys!!!!!!

[175checkmate]

I hope thats solves the propblem. Beats going into the powerhead again.

[Superdave]

Start the motor in the dark with the cowling off. Sometimes you can see the spark jump from coil to spark plug wire.
Dave

[VectorPat]

Well, The coils I had to try were the old style with the little ground wire on them..I took the metal ground strap off of my original coils and put them on the donor coils..Just got back from the lake and it runs much better :D :D!!!! Still has the same topend though..Just seems like it should have more,but I guess thats all this tired little motor can do.. I`ll order new coils monday..

[Talon2.5]

hey pat,

have you done a compression test? just curious what it is thats all ;)

[ShorePounder]

Had the original coil do that very same thing on my inline. You had a couple more coils to keep things going. I didn't :( Glad to see you found the problem. Now it's time to make some go-fast tweaks. :D :D

[VectorPat]

The compression was around 155 with the .100 heads,with the .050`s its 135-140 now..

[Talon2.5]

sounds like it's still fairly stout then :cool:

[B.Mac]

Easy to find..........in the dark with a spray bottle full of salt water. It'll light up like the forth of July.......at least gives you an idea WHERE to begin.
B.MAC:D

[VectorPat]

I dont know how well this would have shown up in the dark..I have never tried the water trick,I`ll have to remember that..There is a rubber boot that goes around it then its under a plastic cover..Anyway its fixed and should hopefully get on plane now with 3 people in the boat:D