could a reed valve cause a lean condition?

[bob johnson]

I have been having an over heat issue slightly with one head of my motor...I have switched temp senders...no change

I have switched t -stats....no change

I have removed the heads and reinstalled...no change

didnt notice anything bad..

the water pressure is reading off the hot head...and it reads about 5-10 lbs at idle and up to 25 at 5500 rpms.

the spark plugs , i am thinking didnt look too much different..

but one heads runs up to 180 at idle many times, but usually over 160, while the other head reads 120-140.

If i throttle up and get going the temps in the hot head drops fast to 120... if i slow down and idle..it creeps up to 160 to 180 degrees.

I rebuild one carb on that side....no change...the water pressure should be the same in both heads... i have taken the t stats out and the temps NEVER get above 100!!

I am trying to figure why the one head is hot....I know I have one carb that wasnt rebuilt on that side..

i have four other carbs all rebuilt and ready for install....asmy next step..

but thought id ask before i start removing everything..if there is a chance....that I may have a lean condition and dont know it...and maybe it could be somethign other than a carb...like a reed valve that isnt closing...maybe???

just thought id ask...

i have run dish soap in my garden hose prior to running on muffs in a hope to clean out the water passages of salt...

compression is 125 across all cylinders

plus are what the book calls out for QL77JC4 gapped at .03

I usually use a little more oil than required..and change out plus twice a year at least

motor is a 1995 Johnson ocean runner 115 J115SLEO

anyone have an ideas?

thanks

bob

 

[DargelJohn]

Re: could a reed valve cause a lean condition?

bob, Reed valves will usually cause a rich condition, due to not sealing properly.

I know you have taken the heads off. Did you check the warpage tolerance? Might have a very small exhaust leak on the overheating cylinder.

 

[bob johnson]

Re: could a reed valve cause a lean condition?

bob, Reed valves will usually cause a rich condition, due to not sealing properly.

I know you have taken the heads off. Did you check the warpage tolerance? Might have a very small exhaust leak on the overheating cylinder.

I actually bought another pair of heads, and fly cut them flat before i installed them...all new seals for the t-stats openings.. and still no change!!

PS: these heads have only two large O-rings between the head and the block!!( no gasket) and you use a little gasket sealer for the water passage..


bob

 

[Tim Frank]

Re: could a reed valve cause a lean condition?

How much did you take off?
I usually lap heads to get them flat....fly-cutters are pretty aggressive...

 

[Big flop]

Re: could a reed valve cause a lean condition?

Sorry if I missed this Q answered already.
Have you done the water pump?

 

[bob johnson]

Re: could a reed valve cause a lean condition?

I think , they cleaned up less than .005" there was a little salt corrosion as the water spots.... I had to reset the T-stat seal depth as well.

the water pump was changed last yea, but the water pressure is notmal...and one head doesnt over heat....so theoretically if the water pump was suspect, id be having both heads over heat...

I have a temp sender in each head!!!!!!!!!

and i switched them , as well as their seperate gauges for all possible combinations..

no change port head wants to get hotter...

bob