RG150 Piston dimensions

[rc_36_rider]

I have been searching the net for hours (obviously in the wrong places!) trying to find the gudgeon pin diameter and gudgeon to piston crown height (compression height I believe) for the RG150 to complete the homework for a project I am wanting to build before I start spending money.
Anyone out there have an old RG150 piston they could measure for me please??

[husaberg]

I have been searching the net for hours (obviously in the wrong places!) trying to find the gudgeon pin diameter and gudgeon to piston crown height (compression height I believe) for the RG150 to complete the homework for a project I am wanting to build before I start spending money.
Anyone out there have an old RG150 piston they could measure for me please??

http://www.tkrj.co.jp/goods/m-AS0650X--12B05.php
http://www.tkrj.co.jp/goods/m-AS0530X--36A06.php

The compression height for a CR80 os piston (wiesco make them)
is 27,00mm
or a 1976-1980 ish RM100 which has a 14mm pin
Other options are using another rod and a YZ100 piston.
or Road bike such as RG400
or kart pistons
Or going to a 24mm restricted 110cc with a 52mm Strike piston. KT100.

[rc_36_rider]

http://www.tkrj.co.jp/goods/m-AS0650X--12B05.php
http://www.tkrj.co.jp/goods/m-AS0530X--36A06.php

The compression height for a CR80 os piston (wiesco make them)
is 27,00mm
or a 1976-1980 ish RM100 which has a 14mm pin
Other options are using another rod and a YZ100 piston.
or Road bike such as RG400
or kart pistons
Or going to a 24mm restricted 110cc with a 52mm Strike piston. KT100.

Hmmm, I have also found the pistons sizes for the RGV 150 but they are different to the RG150 59mm bore vs 61mm on the RG150, interestingly the RGV avd RG125 have the same pin and compression sizes possibly the same as RG150.
I have been thinking about KTM 105 SX they are 14mm pin, you can get a 52 sleeve and piston for them and the stroke is only 1.6mm different to the RG150 so the port location should be close the only question there is will the sleeve be big enough to fit the RG 61mm bore, I have emailed LA sleeve co who make them asking for the od but no answer yet. The other problem is the 105 SX is only 24mm compression height so I would have to take lots off the head and barrel to get the compression up.

Also I dont really want to use an air cooled motors piston, I'm lead to believe they have different clearances if different places compared to water cooled pistons.

It would be nice to know the compression height and pin size for the RG400 as they go out to 52mm oversize.

I'm trying to avoid having a custom 1 off sleeve made. It would be nice to use off the shelf parts making engine refreshments easier and cheaper in the future.

[husaberg]

Hmmm, I have also found the pistons sizes for the RGV 150 but they are different to the RG150 59mm bore vs 61mm on the RG150, interestingly the RGV avd RG125 have the same pin and compression sizes possibly the same as RG150.
I have been thinking about KTM 105 SX they are 14mm pin, you can get a 52 sleeve and piston for them and the stroke is only 1.6mm different to the RG150 so the port location should be close the only question there is will the sleeve be big enough to fit the RG 61mm bore, I have emailed LA sleeve co who make them asking for the od but no answer yet. The other problem is the 105 SX is only 24mm compression height so I would have to take lots off the head and barrel to get the compression up.

Also I dont really want to use an air cooled motors piston, I'm lead to believe they have different clearances if different places compared to water cooled pistons.

It would be nice to know the compression height and pin size for the RG400 as they go out to 52mm oversize.

I'm trying to avoid having a custom 1 off sleeve made. It would be nice to use off the shelf parts making engine refreshments easier and cheaper in the future.

Its highly unlikely LA sleeve make one especially for a Rg150 as they were not sold in the states even more unlikly that they would have one for a 100cc conversion. SO it will end up a one off regardless.Akunar used to sell blanks that where Yow ling got his from. At very resonable prices.
Wiesco used to list the sleeve sizes more than likely they were la Sleeves anyway.
The KTM105 looks nice but pretty sure they have some high mounted windows?


Wob had the sleeve made up for Nigels Rg100 in alloy and it was plated
there is some detail change between the Rg125 and the 150 in regards to the water cooling arround the exhaust port as well as transfer passages and crankshaft.
You could always bin the RG150 cylinder and just use a RGV250 one. or better still a RG125 one as they have a straight plug.

https://www.kiwibiker.co.nz/forums/s...post1130149522
https://www.kiwibiker.co.nz/forums/s...post1130150434

https://www.kiwibiker.co.nz/forums/s...post1130150762
https://www.kiwibiker.co.nz/forums/s...post1130150811
https://www.kiwibiker.co.nz/forums/s...post1130151754
https://www.kiwibiker.co.nz/forums/s...post1130671022
https://www.kiwibiker.co.nz/forums/s...post1130671148
https://www.kiwibiker.co.nz/forums/s...post1130099495
https://www.kiwibiker.co.nz/forums/s...post1129984716

[rc_36_rider]

Its highly unlikely LA sleeve make one especially for a Rg150 as they were not sold in the states even more unlikly that they would have one for a 100cc conversion. SO it will end up a one off regardless.Akunar used to sell blanks that where Yow ling got his from. At very resonable prices.
Wiesco used to list the sleeve sizes more than likely they were la Sleeves anyway.
The KTM105 looks nice but pretty sure they have some high mounted windows?


Wob had the sleeve made up for Nigels Rg100 in alloy and it was plated
there is some detail change between the Rg125 and the 150 in regards to the water cooling arround the exhaust port as well as transfer passages and crankshaft.
You could always bin the RG150 cylinder and just use a RGV250 one. or better still a RG125 one as they have a straight plug.

https://www.kiwibiker.co.nz/forums/s...post1130149522
https://www.kiwibiker.co.nz/forums/s...post1130150434

https://www.kiwibiker.co.nz/forums/s...post1130150762
https://www.kiwibiker.co.nz/forums/s...post1130150811
https://www.kiwibiker.co.nz/forums/s...post1130151754
https://www.kiwibiker.co.nz/forums/s...post1130671022
https://www.kiwibiker.co.nz/forums/s...post1130671148
https://www.kiwibiker.co.nz/forums/s...post1130099495
https://www.kiwibiker.co.nz/forums/s...post1129984716

Thanks for the links, I have tried to read this thread many times but it is crazy long and seems to encompass many builds from different people and pointless banter making it very busy and hard to follow. Its a real shame they didn't make new threads for the other builds. But now I have some starting points to read from cheers.

So far I gather the best barrel to use is the RGV250 VJ22a apparently fits the RG150 cases and ports best and the RG125 head fits this barrel with the centralized plug making it easy to reduce cc wise. Still not sure what 52mm piston to use, need to check dimensions on RG400 2mm oversize pistons.

I heard back from LA sleeve and the 105 sleeve wont fit the RG150 Barrel but it would fit the RGV barrel, I'm thinking I just order one and see how the ports line up. For $100usd it could save lots of hours making a one off sleeve.

I went and looked at a bucket last night and the guy also has and RGV250 and spares so I could at least borrow one of his barrels to do some measurements with to check port alignment to the sleeve.

But now I'm also in the predicament of do I buy and mod an RG150 or finish off his bucket. Was told it was an RG150 running a GT125 motor but it looks like an RG50 Frame, running 18" spooked wheels so will need to change them eventually and still running points so would want to change that strait away and then there is the carb issue of the 2t twin, it currently has a bad 2 into 1 inlet manifold and 24mm carb...

I want to do both projects but only have room for one, hmmm poker night tonight, may have to ask the boys who has room in the shed to spare

[husaberg]

Thanks for the links, I have tried to read this thread many times but it is crazy long and seems to encompass many builds from different people and pointless banter making it very busy and hard to follow. Its a real shame they didn't make new threads for the other builds. But now I have some starting points to read from cheers.

So far I gather the best barrel to use is the RGV250 VJ22a apparently fits the RG150 cases and ports best and the RG125 head fits this barrel with the centralized plug making it easy to reduce cc wise. Still not sure what 52mm piston to use, need to check dimensions on RG400 2mm oversize pistons.

I heard back from LA sleeve and the 105 sleeve wont fit the RG150 Barrel but it would fit the RGV barrel, I'm thinking I just order one and see how the ports line up. For $100usd it could save lots of hours making a one off sleeve.

I went and looked at a bucket last night and the guy also has and RGV250 and spares so I could at least borrow one of his barrels to do some measurements with to check port alignment to the sleeve.

But now I'm also in the predicament of do I buy and mod an RG150 or finish off his bucket. Was told it was an RG150 running a GT125 motor but it looks like an RG50 Frame, running 18" spooked wheels so will need to change them eventually and still running points so would want to change that strait away and then there is the carb issue of the 2t twin, it currently has a bad 2 into 1 inlet manifold and 24mm carb...

I want to do both projects but only have room for one, hmmm poker night tonight, may have to ask the boys who has room in the shed to spare

Id be worried the sleeve id might be too small
did you read through Yow lings and John Tices therads it covers in detail how to mark out and make a sleeve.

[rc_36_rider]

Id be worried the sleeve id might be too small
did you read through Yow lings and John Tices therads it covers in detail how to mark out and make a sleeve.

yep, it's not what I'd consider a hard job if you had a workshop oven (which I don't at the moment) and ideally a mill drill.

It's going to have to be a custom sleeve, the only barrel the ktm sleeve would fit is the RG125 and I can't see any RG125 stuff for sale on ebay or tm.

I asked NZ cylinders what it would cost to make one and the guy I was speaking to just said lots, didn't seem that interested.

I have found a piston I can use, correct pin dia and only 1mm lower compression height and available in many bore sizes from about 48 - 52 mm