Curious about the engine, :question:

GoldenMotor.com

CarpsCustoms

New Member
Jan 27, 2014
108
2
0
Waterbury, Connecticut
NIICCCEEE goood to know. Okay soo i'll use a 3 stage sanding process for the deck,
clean everything up and put it together...I'll post more pics when its together. Thanks map, youre like a motorized mentor lol
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
NIICCCEEE goood to know. Okay soo i'll use a 3 stage sanding process for the deck,
clean everything up and put it together...I'll post more pics when its together. Thanks map, youre like a motorized mentor lol
glad we could help CC

I have to say thank you for the nice words, but I also have to say that in fairness the little bit I know doesnt compare to the knowledge of others here on the forum, Im still learning also and I just do my best to share what I have experienced and the experience of others whom we know we can trust so we can all know as much as possible about all the little things about these fun little engines and the great hobby.

I just try to share information that I hope will help someone the same way I would hope someone would do for me and by the way several people on here have given me a lot of good info and pointers and I appreciate all of it and just try to pass it along.

Best wishes on the engine build up, I hope it will be a good solid runner for you.
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
Just a note to those who order the upper cylinder kit from the link I posted earlier, it is possible that you could end up with a jug that has very small ports, lately I've got three different GT5 jugs from different vendors and they where all the same castings and have very small ports, they all have the same markings on themso its obvious to me that these are all coming from the same place in China, not sure what the reason for all these super small port GT5 jugs is, but I havent run one of them yet.

I guess Im gonna have to clean one up and run it to see what the overall performance is like, personally I cant see it being that good for a desired high rpm build since it looks to me like the flow will be really restricted compared to the standard sized port jugs.

Just wanted to put this out here since I have got three of these lately and had never seen them before.

lately the just listed in the link below has been the only one I've got for the GT5 that has what I call 5he standard medium size ports.

http://pages.ebay.com/link/?nav=item.view&id=321415391334&alt=web
 

Datboy

New Member
Jun 24, 2015
1
0
1
Georgia
No there not exhausting stock from the way it looks to me and the reason i say this is one simple factor that applies primarily to the Half breed engine and that is that the ZAE50 rod is a completely different rod than any of the other in shape and design, the only thing it has in common with the other short rods is just that... it is the same length but if you look is is a different rod and the only engines that use the ZAE50 rod are the half breed engines.

The 40mm stroke engine have NOT gone away, but evidently the 38mm engines must be a better deal for the vendors lately and thats why we're seeing so many of them coming over, when I had a legnthy phone conversation with Uane/thatsdax the other day I ask him about the 40mm stroke engines and he said he can still get them just the same as he did before, he just wanted to go with the current 38mm stroke engines this time around since they are well balanced also and some of his customers have requested them or like them due to the quicker spooling up into rpms that he said some of the racers had claimed.

The Half Breed/ Hybrid is just an added geometry that is not something new, I have one that I bought back in 2010, I didn't realize until recently what it was, but it is for sure a half Breed with the ZAE50 marked rod, only thing different about this old version is that it has narrow crank counters instead of the extra thick ones we're seeing with these Half Breed engines lately.

I honestly don't think anyone is thinning out inventories since the cranks and rods are completely different than are found in any of the 40mm stroke engines, these newer Hybrid engines are just a new mongrel type that takes from bot geometries to create what it actually is and that is a 38mm stroke PK80 40mm stroke variant, yes its a de-stroked 40mm engine plain and simple.

But who actually knows why they have go to this new geometry....?????

Biggest problem I see with the Half Breed is people having know way of knowing what they will get when they order from some vendors, at least in the past we kinda knew who had what, and we had two most common choices.
PK80 40mm stroke or GT5 type 38mm stroke, yes there have always been some variants even in these but now this Hybrid mongrel has added some unfamiliar flavor to the mix.
My experience, says they call it a half breed because they use the same rod in the 49cc and the 66cc . Zae50 I've recently opened up a 49cc engine and it had the same half-breed markings as my favorite former 66cc engine go figure Half Breed they can use it for a 49cc Rod or a 66cc rod