Teflon pad on wrist pin
 

Hi all
I have a evolution 46 nt trainer engine
I pulled the engine apart to inspect it and found only one teflon pad on the end of the wrist pin I believe their should be 2 Does any one know if this was a factory mistake or not
The engine is in perfect shape otherwise
Thanks
Allan

Re: Teflon pad on wrist pin
 

Some engines use only one piece of Teflon and a steel C clip or retainer on the other side. Look for the clip or try to push the wrist pin out the clip side, if you can't it has a steel clip that you should be able to see at the end of the wrist pin. Cheers floyd

Re: Teflon pad on wrist pin
 

Thanks Floyd
There doesn't seem to be any clips and the pin seems to be a press fit as the pin will not slide or turn in the piston Don't forget this is the trainer engine so is probably the cheapest version

Re: Teflon pad on wrist pin
 

Horizon lists a replacement wrist pin for that motor. You may be right about the press fit. Can you see any groves for a C clip on the end of the wrist pin? Because the replacement below comes with clips. Cheers floyd
Wrist Pin & Clips: E40 (EVO040213)

Re: Teflon pad on wrist pin
 

yes I checked that part out and that part is used on several 40 to 46 model engines
but I don't see any grove for the ring
If it is just a press fit why only one teflon pad
Oh yes it is $26.00 to get a$5.00 part from Horizion hobby

Re: Teflon pad on wrist pin
 

A perfect question for horizon hobbies, do you have a parts breakdown in the manual instructions ? That may show something. My past experience is engines should have something to retain the wrist pin urself from rubbing against the cylinder wall

Re: Teflon pad on wrist pin
 

Yes Len Good point The drawing shows the wrist pin and it looks like the one teflon pad and description says Wrist Pin w/Clips[Teflon]
Now are the clips the Teflon pads

Re: Teflon pad on wrist pin
 

In the past depending on the manufacturer ; most used metal wire clips as was probably cheaper but easier to get lost when trying to take off or re-install. And very hard to find on the floor afterwards....lol not sure just who brought in the Teflon pads. Could be wrong but don't think there was both. could be a Teflon pad on one end of the pin and a circlip on the other.

Found the parts breakdown and looks like one Teflon pad . sometimes what they do is not machine the wrist pin diameter all the way thru so the w/pin can only be inserted from the one side and then the Teflon pad goes in that pin side.

That is what I have found is that HH tend to leave some guessing out there on most of their products so that customers tend to mail in rather than self fix. Ie like radio parts ; box it up and send off were other brands will sell you any part they have and if you feel confident enough to self fix; then go for it.

$26.00 to mail a wrist pin ? a mite excessive, I would think. That would definitely sway me to shop around for my purchases and stick with those that have reasonable mailing and tell them, why also. on the other hand maybe email and suggest that they mail USPS first class mail as that is probably their automatic priority mailing list. Worth checking with them and if not have your local hobby shop order for you next time they order.

Re: Teflon pad on wrist pin
 

Yes I just found out this is a 40 Alpha engine but doesn't change anything I just didn't want to pull the wrist pin out of the piston as it seems OK
I was hoping someone here might have done this already if not a call to Horizon is in order Thanks

Re: Teflon pad on wrist pin
 

Saito and OS 4-Strokes use two Teflon pads. I've seen motors with one cir-clip and one Teflon pad. Where your wrist pin goes in the piston you should be able to see a grove on both sides where a clip would fit in. It wouldn't make any sense to manufacture 2 different pistons for the same motor. I think it could be tapered and uses only one Teflon pad like you said, especially if you can't see a groove for a clip. Cheers floyd