Crank options for kx 107 or 109 supermini

brocsdad
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brocsdad
Edited Date/Time 8/21/2014 11:15am
I was looking at supermini options for the 2014 kx100. It seems every tuner I have spoke with except PC uses the hot rods stroker crank.

I want to stay with a 109 or below because the 112's are very high maintenance.

Does anyone have experience with super mini kx's with the stroker hot rod cranks?

Opinions?
|
slipdog
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slipdog 8/17/2014 6:04pm
8/17/2014 6:04pm
I had a father of a WORCS rider that wanted one put in his back in 2008. I advised against because I personally don't care for Hot Rods. Stroking and balancing the stock crank was going to take too long(2-3 weeks) for him so In went the Hot Rods crank with the head cut to the specs Eric Gorr recommended to me.

Performance wise, like a big bore, the motor was snappier down low, but ran flat on the top end. Eventually I added a second base gasket and removed the extra .020" from the face of the head and that brought a decent amount of over rev back. The crank tested about .002" runout before installation, yet after one practice day for break in, the big end let go 30 minutes into the very next WORCS race.

Long story short, I rebuilt the crank with an OEM bearing and thrust washers and the motor lasted the rest of the season and is still running as far as I know.
brocsdad
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brocsdad 8/17/2014 7:25pm
8/17/2014 7:25pm
Who was going to stroke and balance your crank? I'm willing to wait to ensure reliability.

I have had several motors modded by our builder and they have all turned out great. The stock kx 100 has ok mid and bottom but goes really flat on top. When installing any big bore you must port the cylinder and set the timing to get the top end overrev.

slipdog
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slipdog 8/17/2014 9:18pm
8/17/2014 9:18pm
I have have most of my crank work done by Crank Works in AZ.
Spinnin t's
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Spinnin t's 8/18/2014 2:49pm
8/18/2014 2:49pm
Hot rods and Wisco product is crap. For the best way you want to move crank pin location and do what we call a short rod stroker. A long rod stroker messes up the rod ratio and prove to be not the most reliable.

The Shop

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Jakes Dad
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Jakes Dad 8/19/2014 6:19pm
8/19/2014 6:19pm
Flat on top usually means squish not reconfigured to the 50 to 55% optimal range. Ran a 112 for 25 hours at a time before 10% drop off in compression. Motor was very reliable BUT it was carefully set up with port timing and squish right on. Was looking forward to running a 112 with a 6mm stroker but once he got on a 125 we were done on the mini's.

TDC 2 Stroke did all my porting and guided me on proper tuning and setup. Best choice I ever made.
brocsdad
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brocsdad 8/20/2014 12:28pm
8/20/2014 12:28pm
Spinnin t's wrote:
Hot rods and Wisco product is crap. For the best way you want to move crank pin location and do what we call a short rod...
Hot rods and Wisco product is crap. For the best way you want to move crank pin location and do what we call a short rod stroker. A long rod stroker messes up the rod ratio and prove to be not the most reliable.
My builder will not use Wiseo pistons or cranks but he has been buildng superminis (over 100 this year) with the Hot-Rods Cranks with no reported issues.

He is willing to send the crank to crank works but it will cost $600 more. He said if my kid was a top 3 national level rider it was worth it because they can stroke it 3mm. For the average racer he felt it was a waste of money.

I have read about some hot-rod issues but the posts seem to older.

Do you know of anyone recently who had issues?
brocsdad
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brocsdad 8/20/2014 2:05pm
8/20/2014 2:05pm
Jakes Dad wrote:
Flat on top usually means squish not reconfigured to the 50 to 55% optimal range. Ran a 112 for 25 hours at a time before 10%...
Flat on top usually means squish not reconfigured to the 50 to 55% optimal range. Ran a 112 for 25 hours at a time before 10% drop off in compression. Motor was very reliable BUT it was carefully set up with port timing and squish right on. Was looking forward to running a 112 with a 6mm stroker but once he got on a 125 we were done on the mini's.

TDC 2 Stroke did all my porting and guided me on proper tuning and setup. Best choice I ever made.
The stock KX 100 is flat on top because it's basically a kx 85 with a big bore. So yes my motor builder would port and set timing for the stroker kit.
Jakes Dad
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Jakes Dad 8/20/2014 6:06pm
8/20/2014 6:06pm
Spending that much I'd go 6mm on the crank.
brocsdad
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brocsdad 8/20/2014 6:35pm
8/20/2014 6:35pm Edited Date/Time 8/20/2014 6:37pm
It seems a lot of people associate Hot Rods with Wiseco. At one time Wiseco did distribute the Hot Rods cranks. I called Crank Works and they said they have not seen any issues with the Hot Rod cranks. The owner was honest and very informative. He even said the 14 OEM crank did not really require balancing. Again great guy!

Hot Rod's cranks are made in Taiwan and the crank rod is made in the U.S. The bearings they use are the same bearings installed in the OEM cranks. I have 2 friends who just installed Hot Rods strokers so I will see how it goes.

Spinnin t's
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Spinnin t's 8/20/2014 10:58pm
8/20/2014 10:58pm
Spinnin t's wrote:
Hot rods and Wisco product is crap. For the best way you want to move crank pin location and do what we call a short rod...
Hot rods and Wisco product is crap. For the best way you want to move crank pin location and do what we call a short rod stroker. A long rod stroker messes up the rod ratio and prove to be not the most reliable.
brocsdad wrote:
My builder will not use Wiseo pistons or cranks but he has been buildng superminis (over 100 this year) with the Hot-Rods Cranks with no reported...
My builder will not use Wiseo pistons or cranks but he has been buildng superminis (over 100 this year) with the Hot-Rods Cranks with no reported issues.

He is willing to send the crank to crank works but it will cost $600 more. He said if my kid was a top 3 national level rider it was worth it because they can stroke it 3mm. For the average racer he felt it was a waste of money.

I have read about some hot-rod issues but the posts seem to older.

Do you know of anyone recently who had issues?
This is my deal with these products... Hot rods and wiseco.... When I first got a handle on engines,not just the basics but the machine work and truing side, back in 2005. These products did not fit my "style" of building. The cranks was .003 out of true out of the box. After I got them true within .0005 they would be fine but not for long would they shake like I don't know what. Well If I have to true the damn things I may as well rebuild them from stock parts. As for the pistons... Getting tech with it is a waist of time... JUNK! So saying that I moved to quality vs quantity on my work load. I have a team of specialist that have more world titles in f1,Indy,gp's,and every other form of racing known to man. For the record pro circuit don't make a damn thing. The people I use make there parts. Special and book parts. These contacts was passed down to me by my non formal teacher. Never went to a school. . If you're not on the inside your getting mid grade shelf parts and service. I don't do that any longer. All that said I would not know how good there stuff is now because they lost my business a long time ago.
motofab36
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motofab36 8/21/2014 4:39am
8/21/2014 4:39am
Spinnin t's wrote:
Hot rods and Wisco product is crap. For the best way you want to move crank pin location and do what we call a short rod...
Hot rods and Wisco product is crap. For the best way you want to move crank pin location and do what we call a short rod stroker. A long rod stroker messes up the rod ratio and prove to be not the most reliable.
brocsdad wrote:
My builder will not use Wiseo pistons or cranks but he has been buildng superminis (over 100 this year) with the Hot-Rods Cranks with no reported...
My builder will not use Wiseo pistons or cranks but he has been buildng superminis (over 100 this year) with the Hot-Rods Cranks with no reported issues.

He is willing to send the crank to crank works but it will cost $600 more. He said if my kid was a top 3 national level rider it was worth it because they can stroke it 3mm. For the average racer he felt it was a waste of money.

I have read about some hot-rod issues but the posts seem to older.

Do you know of anyone recently who had issues?
Spinnin t's wrote:
This is my deal with these products... Hot rods and wiseco.... When I first got a handle on engines,not just the basics but the machine work...
This is my deal with these products... Hot rods and wiseco.... When I first got a handle on engines,not just the basics but the machine work and truing side, back in 2005. These products did not fit my "style" of building. The cranks was .003 out of true out of the box. After I got them true within .0005 they would be fine but not for long would they shake like I don't know what. Well If I have to true the damn things I may as well rebuild them from stock parts. As for the pistons... Getting tech with it is a waist of time... JUNK! So saying that I moved to quality vs quantity on my work load. I have a team of specialist that have more world titles in f1,Indy,gp's,and every other form of racing known to man. For the record pro circuit don't make a damn thing. The people I use make there parts. Special and book parts. These contacts was passed down to me by my non formal teacher. Never went to a school. . If you're not on the inside your getting mid grade shelf parts and service. I don't do that any longer. All that said I would not know how good there stuff is now because they lost my business a long time ago.
Wow you sound so awesome......I'm starstruck
brocsdad
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brocsdad 8/21/2014 6:43am
8/21/2014 6:43am
Spinnin t's wrote:
Hot rods and Wisco product is crap. For the best way you want to move crank pin location and do what we call a short rod...
Hot rods and Wisco product is crap. For the best way you want to move crank pin location and do what we call a short rod stroker. A long rod stroker messes up the rod ratio and prove to be not the most reliable.
brocsdad wrote:
My builder will not use Wiseo pistons or cranks but he has been buildng superminis (over 100 this year) with the Hot-Rods Cranks with no reported...
My builder will not use Wiseo pistons or cranks but he has been buildng superminis (over 100 this year) with the Hot-Rods Cranks with no reported issues.

He is willing to send the crank to crank works but it will cost $600 more. He said if my kid was a top 3 national level rider it was worth it because they can stroke it 3mm. For the average racer he felt it was a waste of money.

I have read about some hot-rod issues but the posts seem to older.

Do you know of anyone recently who had issues?
Spinnin t's wrote:
This is my deal with these products... Hot rods and wiseco.... When I first got a handle on engines,not just the basics but the machine work...
This is my deal with these products... Hot rods and wiseco.... When I first got a handle on engines,not just the basics but the machine work and truing side, back in 2005. These products did not fit my "style" of building. The cranks was .003 out of true out of the box. After I got them true within .0005 they would be fine but not for long would they shake like I don't know what. Well If I have to true the damn things I may as well rebuild them from stock parts. As for the pistons... Getting tech with it is a waist of time... JUNK! So saying that I moved to quality vs quantity on my work load. I have a team of specialist that have more world titles in f1,Indy,gp's,and every other form of racing known to man. For the record pro circuit don't make a damn thing. The people I use make there parts. Special and book parts. These contacts was passed down to me by my non formal teacher. Never went to a school. . If you're not on the inside your getting mid grade shelf parts and service. I don't do that any longer. All that said I would not know how good there stuff is now because they lost my business a long time ago.
The Hot Rods Cranks in 2005 and today are not the same. The guy from Crank Works was very honest and very informative. He even backed up what Barr’s Competition told me. He could have said the Hot Rods cranks were junk to try and sell me on a crank but he didn’t. So far no one has recommended the Wiseco cranks.

Barr’s Competition has more Championship motors than I can count and has been building motors for 30 years. I trust Bobby’s opinion. Like I said in my previous post (2) local kids are running the Hot Rods stroker cranks so I will see how it goes with them.

As far as PC we all know the parts are not made in house and Mitch Payton is not going to do your motor.

What type of motors are you building? MX? Street?

Spinnin t's
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Spinnin t's 8/21/2014 11:15am
8/21/2014 11:15am
I'm just old school in the way that if something fails to be what it is supposed to be I just don't go back. As far as to what I build.. I don't do it for a living anymore. Just when someone ask and it's something I want to do or worth doing I'll take it on. Mx was my primary customers,wrenching for Tisco also. and here and there's range from drag bikes to 600cc motors in sprint cars. I do a little with harleys also now. Those are fun! I'm really a tuner of anything that races. I watch you ride and Taylor a engine to fit the rider. I'm about lap times and not peak power.
smokinjoe909 6/24/2016 8:41pm
6/24/2016 8:41pm
Jakes Dad wrote:
Flat on top usually means squish not reconfigured to the 50 to 55% optimal range. Ran a 112 for 25 hours at a time before 10%...
Flat on top usually means squish not reconfigured to the 50 to 55% optimal range. Ran a 112 for 25 hours at a time before 10% drop off in compression. Motor was very reliable BUT it was carefully set up with port timing and squish right on. Was looking forward to running a 112 with a 6mm stroker but once he got on a 125 we were done on the mini's.

TDC 2 Stroke did all my porting and guided me on proper tuning and setup. Best choice I ever made.
hello i was wondering if anyone has an idea on what squish should be at on the 6mm kx112..when we had the motor built they never told us there was 2 base gaskets until i went to rebuild and found them..i used a caliper and there was a .020 and .010 so i asked the builder to verify and they said oh just use 2 stock ones and i said the squish would be pretty loose then a week later they verified it was a 20 and a 10..so i bought 10 .030 base gasket so i wouldnt need 2 base gaskets..bike runs great but i thought i would check squish with .050 solider and the piston barely touches it.

i race shifter karts also and the kx112 is my daughters and she took 3rd at our regional last weekend and got her golden ticket in girls sr woohoo..

with the cr 125 shifter kart we would run 32 to 35 thousandths squish measured with 50 thousandths solider..

anybody have an idea what i should be at?
thanks
cwtoyota
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cwtoyota 6/24/2016 9:26pm
6/24/2016 9:26pm
slipdog wrote:
I had a father of a WORCS rider that wanted one put in his back in 2008. I advised against because I personally don't care for...
I had a father of a WORCS rider that wanted one put in his back in 2008. I advised against because I personally don't care for Hot Rods. Stroking and balancing the stock crank was going to take too long(2-3 weeks) for him so In went the Hot Rods crank with the head cut to the specs Eric Gorr recommended to me.

Performance wise, like a big bore, the motor was snappier down low, but ran flat on the top end. Eventually I added a second base gasket and removed the extra .020" from the face of the head and that brought a decent amount of over rev back. The crank tested about .002" runout before installation, yet after one practice day for break in, the big end let go 30 minutes into the very next WORCS race.

Long story short, I rebuilt the crank with an OEM bearing and thrust washers and the motor lasted the rest of the season and is still running as far as I know.
After watching this video where they claim to be made in USA, I purchased a Hot Rods connecting rod kit for my YZ250.
The box clearly says made in Taiwan. The problems I've seen with offshore forgings is that they shatter when the bearing seizes (Wiseco rods seem to do this). The Japanese made OEM Yamaha rods don't shatter if the bearing fails. Cases are expensive, OEM rods are worth it.

https://www.youtube.com/watch?v=bXX7pnMcPeg

smokinjoe909 6/24/2016 9:51pm
6/24/2016 9:51pm
Hot rods tawain and wiseco china.. i always use oem rods or pro x on the stock crank if possible
smokinjoe909 9/29/2016 11:52am
9/29/2016 11:52am
Jakes Dad wrote:
Flat on top usually means squish not reconfigured to the 50 to 55% optimal range. Ran a 112 for 25 hours at a time before 10%...
Flat on top usually means squish not reconfigured to the 50 to 55% optimal range. Ran a 112 for 25 hours at a time before 10% drop off in compression. Motor was very reliable BUT it was carefully set up with port timing and squish right on. Was looking forward to running a 112 with a 6mm stroker but once he got on a 125 we were done on the mini's.

TDC 2 Stroke did all my porting and guided me on proper tuning and setup. Best choice I ever made.
smokinjoe909 wrote:
hello i was wondering if anyone has an idea on what squish should be at on the 6mm kx112..when we had the motor built they never...
hello i was wondering if anyone has an idea on what squish should be at on the 6mm kx112..when we had the motor built they never told us there was 2 base gaskets until i went to rebuild and found them..i used a caliper and there was a .020 and .010 so i asked the builder to verify and they said oh just use 2 stock ones and i said the squish would be pretty loose then a week later they verified it was a 20 and a 10..so i bought 10 .030 base gasket so i wouldnt need 2 base gaskets..bike runs great but i thought i would check squish with .050 solider and the piston barely touches it.

i race shifter karts also and the kx112 is my daughters and she took 3rd at our regional last weekend and got her golden ticket in girls sr woohoo..

with the cr 125 shifter kart we would run 32 to 35 thousandths squish measured with 50 thousandths solider..

anybody have an idea what i should be at?
thanks
anybody have any info on my above post? thanks joe
Jakes Dad
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Jakes Dad 9/30/2016 6:50pm
9/30/2016 6:50pm
www.torqsoft.net. Has a squish calculator tool on website, it explains how to measure before calculating.

Pit Row

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gamakona
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gamakona 10/1/2016 1:22pm
10/1/2016 1:22pm
I owned 2 pro circuit built kx 109s , a 2012 and 13. Incredible performance and built proof. We ran 50 hours ( pc says 25 hours ) on a crank with at top supermini ridrer. these cranks can be rebuilt for cheap with oem parts. I even have a brand new rebuilt pc crank and new renicked, ported pc cyl and head for sale cheap. Highly recommend .
sticecube
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sticecube 10/3/2016 2:44pm
10/3/2016 2:44pm
What we used to do was buy a stock 85 cyl and pump it out to a 100 because the smaller ports = more horsepower and them would do the stroker crank to pump it out to a 105 running a 50/50 mixture or 91 and 112 mixed at 40:1. Bike was super reliable and ripped. Id look into doing something like that.
FahQ
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FahQ 10/7/2016 5:04pm
10/7/2016 5:04pm
I have had a hot rods stroker crank for 2 seasons no issues. I also did not have the head or cylinder modified, other than opening up the exhaust port. I ordered custom gaskets from Cometic in 1.2mm thickness. This is a stock bore 100. Wossner single ring piston. Turned the motor from a mid hit only powerband to more power everywhere. Knowing the stock 100 cylinder is under ported i wanted to make the most of the stock ports as possible.

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