mazdab2600

the pullstart screws.i put just snug with loctite.
and the shims are listed in the manual hpi#15228.
not sure on the nova head.
looked for a pic and could not find a good pic.
the button head is part of the cooling head.so yes there will be a small gap.
while its running you can check around the gap for bubbles.
if it leaks try to retighten the head in a criss-cross x pattern like the manual says to equal out the torque on the head.
http://www.hpieurope.com/manuals/pdf/15201.pdf

BigGrump

The shims are very thin, sometimes there is only one, and sometimes there are two. Usually not more than that. They go between the head button and the cylinder. The head button is the round piece that the glow plug screws into. The head button is made so it slips into the cylinder about 1/16 inch, and the shims both help seal, and provide spacers that adjust how far the head button slips into the cylinder.

Sometimes the shims stick a little to the head button, and you would swear there is none there, but when you look closely and pick at it with your finger nail, then they pull away. Very thin aluminum or brass pieces. Anyway, when you re-assemble, make sure everything is very clean, and put the head button and shim(s) into the cylinder so they sit square. At that point you are done with the hard part. The cooling head then simply bolts down to the head button and acts to hold the head button to the cylinder, thereby sealing it. The cooling head then only acts like a heat sink, pulling heat away from the head button and transferring it to the air.


I assume you are squared away with the one way bearing. From one of the pictures, previously posted, you can not only see the one way bearing, but also the little rollers inside of it. When you are spraying it with cleaner or wd40, or both, just be careful not to get so powerful with the cleaning that you dislodge and remove any of the rollers, which has happened to me. If that happens, then you need a new one, otherwise, a cleaning will fix it for a while. What usually goes wrong, is from using a fuel that either has a little too much oil or the type of oil that gets in there and sticks it up a little.

Good luck, don't worry, these things are ment to be taken apart, many times in their lifetime. You are only doing routine maintenance.

LOL

Dennis

naynay12

Ok,i found the shims on the old head,they are very thin.The gap between the head and the engine case is about 2mm,so the shimms dont cover the hole gap.What is wrong any suggestions? Thanks nathan.

naynay12

anyone?

BigGrump

Forget about the gap between the cooling head and engine case. The cooling head does not touch the engine case. The cooling head makes contact with the head button, that is the piece that holds the shims and glow plug. All the cooling head does is provide pressure against the head button, and that seals against the piston sleeve and engin block. You are looking as something that is not a problem.

Dennis

naynay12

Ok,in was just worried since the head button is actually in the cooling head,and i could see the piston,and head bolts. Thanks alot.

BigGrump

Sorry, I just assumed you hade a seperate head button from the cooling head. In your case the part of the coolling head that has the spacer shims on, simply goes inside the cylinder and the shims and the edge they touch from the cooling head make contact and seal against the cylinder. When viewed from the side, the remaining part of the cooling head would appear to be spaced up, but watch from the side when you put it together, and you will see the part I talked abut previously slip into the cylinder and drop in to make a seal.

Hope that is clear.

Dennis

fighttheban

thanks mazdab do you think oil could be leaking into my 1-way bearing from inside the backplate? and if so, what are the chances of fixinkg this leak? thanks

horeable

correct me if I am wrong but the 1 way bearing is behing the backplate. so i dont see how there would be anything leaking oil into it that could be fixed.

I found my one way started to slip as soon as i tried a gallon of blue thunder. It might have been i forgot after run oil a couple times too. I usually clean mine with wd40. I have found i can pretty much fill the engine with wd40 and crank it several times and that can help unstick it too.

my best advice is switch fuels, i always used odonells and rocketscience without problems.

naynay12

Yeh in the k4.6 the owb is behind the backplate...thanks big grump you have been a great help and everyone else...yes i understand now. Thanks alot,i should be due in for a run today or tomorrow!

naynay12

GRR again!I finished putting it all back together and what do you know...the same problem.
Last night when i was just about to start putting it back together i check the pullstart again and i had the same problem.So i took the owb out again and found out that the shaft(dont know its real name)that connects the pullstart to the owb was oily so i cleaned that and the owb once again.So everything was working well again.Then this morning when i finished putting it back together i found the exact same problem.Why do you think?Is it because it could be something else,or i did not clean a part or what? Thanks guys.

BigGrump

You might have a problem with how you put the one way bearing back into the engine and how it engages the crankshaft. Sometimes it is a little tricky to have it engaged properly when you install the backplate and shaft. Look carefully when you start to put it together so you, for sure, understand how it goes together.

Second, after it is all put together including the pull starter, take the glow plug out so it is easy to turn over and pull the pull starter many times, so you can make sure nothing is locking up inside the engine. If that is OK, then install the glow plug and try again. Should work perfect. If the one way bearing is slipping (not engaging) after all this, perhaps you need a new one way bearing and maybe even a new shaft. I believe in your engine there is also a little spring that is between the shaft and pull starter that keeps the shaft pushed in all the way when the pull starter is installed.

Just seems to me like something is mechanically wrong. You might need to take the engine to someone who knows how they should be to inspect both the equipment and your work.

Good Luck

Dennis

naynay12

Ok,and what do you mean by its a bit tricky to have it properly engaged?

Nathan