Only firing on 2 cylinders, Same side so its not cam Options

[skline]

The odds of having 2 bad valve seats on the same head which was just done by Rimco less than 1000 miles ago is highly unlikely. We will find out what it is tomorrow and post the results. I am still betting its lifters, either collapsed or broken. It pops on the cylinders when the RPM's go up. See who guesses the resolve. Winner gets a Boobie prize. (IMG:style_emoticons/default/biggrin.gif)

[Aaron Cox]

loose rockers or bad lifters is my guess...

hows it goin scott?

[skline]

I aint touching mine again till Friday. Jared said he was going to come out and help me. I have to cut the mounts for the exhaust (Hangers) and then remove the muffler system to get the transmission out so I can make the modification that Renegade said. Should have it out and done in about 3 or 4 hours. Then its time to adjust the clutch and see if it moves on its own. While I am at it, I am going to figure out some way of making the exhaust removable without cutting the hangers again.

[JB 914]

ok..so its strictly mechanical then.... cam - lifter - pushrod - rocker - valve - valve seat pick your poison

I'm gonna pretend it's the fuel injection problem even though i have Carbs.

let me live in DENIAL at least one more night (IMG:style_emoticons/default/ohmy.gif)

[DrifterJay]

yeah me 2...hehe... (IMG:style_emoticons/default/biggrin.gif)

[DJsRepS]

Pull coil wire and turn engin over to hear if it has a dead compression, cylinder if in doupt pull the plugs and use tool. Assumeing it has enough to fire all 4 and you have fuel inj then check the trigger points with ohm meter or pull the dist and clean and inspect and Ohm out with meter anyway. As for your valve motion the best one can do without rebuild is valve adjustment and or pull pushrods inspect for bent. (Slim chance of bent) Also check all grounds at block under intake!!

[DJsRepS]

Scratch the trigger points I didnt read page 2. Good luck.

[JB 914]

compression seem pretty low on both cylinders. didn't have time to check the 'good' side

so, it looks like rings (IMG:style_emoticons/default/headbang.gif) (IMG:style_emoticons/default/headbang.gif) (IMG:style_emoticons/default/headbang.gif) (IMG:style_emoticons/default/headbang.gif)

less than 1500 miles. i guess they never seated.

looks like i'm pulling it out and tearing it down again. (IMG:style_emoticons/default/barf.gif)

anyone up for a rebuilding party? i'll smoke some good pork w/ home made BBQ sauce (IMG:style_emoticons/default/chowtime.gif)

[Aaron Cox]

compression seem pretty low on both cylinders. didn't have time to check the 'good' side

so, it looks like rings (IMG:style_emoticons/default/headbang.gif) (IMG:style_emoticons/default/headbang.gif) (IMG:style_emoticons/default/headbang.gif) (IMG:style_emoticons/default/headbang.gif)

less than 1500 miles. i guess they never seated.

looks like i'm pulling it out and tearing it down again. (IMG:style_emoticons/default/barf.gif)

anyone up for a rebuilding party? i'll smoke some good pork w/ home made BBQ sauce (IMG:style_emoticons/default/chowtime.gif)

that sucks! you sure the valves are closing all the way?


(IMG:style_emoticons/default/wacko.gif) (IMG:style_emoticons/default/beerchug.gif)

[JB 914]

compression seem pretty low on both cylinders.  didn't have time to check the 'good' side

so, it looks like rings (IMG:style_emoticons/default/headbang.gif)  :headbang:  :headbang:  :headbang:

less than 1500 miles.  i guess they never seated.  

looks like i'm pulling it out and tearing it down again.   (IMG:style_emoticons/default/barf.gif)

anyone up for a rebuilding party?  i'll smoke some good pork w/ home made BBQ sauce (IMG:style_emoticons/default/chowtime.gif)

that sucks! you sure the valves are closing all the way?


(IMG:style_emoticons/default/wacko.gif) (IMG:style_emoticons/default/beerchug.gif)

compression held and did not go down, so, i don't think it's valves. it was 75 on one and about 85 on the other one.

i pulled off both valve and they were moving about the same on both sides, so, i'm ruling out lifters.

that compression seems way too low. i thought it should be over 100? i'm not sure what is acceptable.

[ematulac]

I had the same exact problem when my car sat in storage for a few years.

Remove the top of the carb and check the float and the needle valve.

What I found in mine was that the little wire spring that goes on the end of the needle valve had corroded to gunk and was keeping the needle valve from opening. So basically, the carb was getting gas but the gas wasn't flowing through the carb.

Hope that helps. (IMG:style_emoticons/default/wink.gif)

[skline]

The gas is flowing through the carb, you can open the throttle plates while its running and watch the fuel flow in, he removed the plugs and they were wet so he is going to pick up some new plugs and try it again. When we pulled the heads off last time I remember noticing there was a lot of deck height (Space between the top of the piston and the head) so I am thinking that is why the compression is so low. If it were mine, I would take the cylinders to Rimco and have about 1/4 inch or so shaved off the top and then replace the rings and lap them in again and run it. I am sure he could take off at leasst 1/4 inch off the top and even still have too much deck height. As I recall, there was about 1/2 inch or so. The guy he bought this engine kit from was building it for a plane so the low compression would be what the guy was shooting for. I would bet the other 2 cylinders are about the same compression.