Cylinder spacer, Rev3 270

[jbrandt]

I've been considering a cylinder head spacer for my 2000 Rev3 270.  

When I see videos of folks (granted, on much more modern bikes) it almost seems like they just let the weight of their leg fall on the lever and it starts.  And I'm jealous, I feel like I have to hulk out on mine and put my full body weight on it. I'm also coming off an injury (dual broken wrists), so I'm sure there's some strengthening to do as well, but it was a beast to start before my injuries, too.

So, I'm thinking a head spacer may do the trick.  I'm not worried about the loss in power, a 270 is *more* than enough for a novice trial rider like me.  I found this thread from 2013 that mentioned you could go as much as a 3mm spacer (actually x3 1mm spacers) could work, but that was for a gasgas, so not sure how well that applies to my 270...

The other issue is finding parts.  It's an old bike so parts are always hard to find.  I also live in the States, which makes parts for a 21 year old Italian trials bike even harder to find...

 

And before anyone tells me just to get a smaller displacement bike...  Look, my trials bike is old enough to buy alcohol, do you think I have the money for a another bike?  lol

 

cheers, and thanks

Edited April 8, 2021 by jbrandt

[trialman]

best priced option is to buy a piece of 2mm alloy plate [you could probably pick up an off cut if you have any engineering companies nearby?] buy 2 base gaskets and copy around one onto sheet, cut it out and fit onto bike.[ive done this on a couple of bikes to tone them down. it does make kickstarting easier and makes finding grip far better. I used to have a beta gara 260 and the power was far too much, doing this mod made it far more enjoyable to ride

 

[mcman56]

See picture.  A thicker head gasket would be hard to make unless you had a friend with a CNC.  I believe a company makes custom copper head gaskets for the drag race crowd but I have not looked into it.  I'm guessing they are laser cut and they would want a CAD file.  The easy path would be extra base gaskets.  Technos and Gas Gas use o rings for head gaskets so it is much different.  The spark plug hole is central to the cylinder head dome so it is easy to set up in a lathe but removing material is permanent and if you go too far you can hit the water ports.        

I have ridden 2 different 300 super smooths and they were both very easy to kick, nothing like the standard 300 2t but published compression ratios are the same.  If you could find out what makes them so easy to kick, maybe it could be duplicated.  (I would like to know.) Some people have claimed that all 300s sold in the UK are super smooths but I don't know if that is true.  Could different porting do that?  The super smooths were also very soft off the bottom.  Rev and Evo engines are pretty much the same so what works for one would likely work for the other. 

I have an 02 270 and it looks like the same bike as yours except for the USD forks.  It is hard to kick, loud and the off idle power is pretty sharp, sharper than I remember on my 300 Factory 2t.  I'm in the process of installing a 250 top end to see if that helps.     

Lewisport is the local trials bike dealership.  Capitol Yamaha is a Beta dealer and can get parts.  You just need to get a parts list and order by part number.  My air filter looks the same and I got one from Trials Super Store.  Beta Uk has a great on line ordering system but for some reason shipping has recently jumped from 5 or 10 pounds to 35 pounds.

Rev3s are not bad bikes.  Having a green sticker bike makes it legal to ride at Prairie City in summer and it is a big advantage to have a local riding area.         

       

 

 

 

[jbrandt]

1 hour ago, mcman56 said:

See picture.  A thicker head gasket would be hard to make unless you had a friend with a CNC.  I believe a company makes custom copper head gaskets for the drag race crowd but I have not looked into it.  I'm guessing they are laser cut and they would want a CAD file.  The easy path would be extra base gaskets.  Technos and Gas Gas use o rings for head gaskets so it is much different.  The spark plug hole is central to the cylinder head dome so it is easy to set up in a lathe but removing material is permanent and if you go too far you can hit the water ports.        

I have ridden 2 different 300 super smooths and they were both very easy to kick, nothing like the standard 300 2t but published compression ratios are the same.  If you could find out what makes them so easy to kick, maybe it could be duplicated.  (I would like to know.) Some people have claimed that all 300s sold in the UK are super smooths but I don't know if that is true.  Could different porting do that?  The super smooths were also very soft off the bottom.  Rev and Evo engines are pretty much the same so what works for one would likely work for the other. 

I have an 02 270 and it looks like the same bike as yours except for the USD forks.  It is hard to kick, loud and the off idle power is pretty sharp, sharper than I remember on my 300 Factory 2t.  I'm in the process of installing a 250 top end to see if that helps.     

Lewisport is the local trials bike dealership.  Capitol Yamaha is a Beta dealer and can get parts.  You just need to get a parts list and order by part number.  My air filter looks the same and I got one from Trials Super Store.  Beta Uk has a great on line ordering system but for some reason shipping has recently jumped from 5 or 10 pounds to 35 pounds.

Rev3s are not bad bikes.  Having a green sticker bike makes it legal to ride at Prairie City in summer and it is a big advantage to have a local riding area.         

       

 

 

 

Yes, the green sticker is definitely an advantage.  I was glad to get one since trials bikes are often referred to as "grey sticker" bikes.  My brother is State Parks OHV law enforcement, and was telling me some DMVs are pretty strict about how the "3 or a C" in the VIn is interpreted.  Some have had issues that if it doesn't have a 3 OR a C it wouldn't even qualify as a red sticker even if it's old enough like mine is to be grandfathered.

Yeah, I had previously gotten ahold of a guy from Beta USA and he said the 2000's are pretty much the same as 01-03's aside form the fork. 

 

I considered converting to like a 250 since I think the bottoms are the same, but that's also a pricey option (saw cylinders for like $500+) unless I can wave a magic wand and find a used top end somewhere.

Thanks for the info.

[dan williams]

There are times kicking my ‘18 300 feels like kicking a cinder block. The new bikes aren’t always easy kickers.

[mcman56]

Well, The 250 top end is marked with an 02 on the side and I ran it on a 2008 Rev 3 but it does not match the 2001 engine.  The 250 cylinder has an extra port on the side for a coolant hose from the water pump.  It looks like the 01 runs water through the cases and up into the cylinder.  The 250 cylinder still has ports down to the cases so may work if I just plug up that extra port.  I have to think about that some more so decided to reassemble with the 270 top end and an extra 1 mm of base gasket.  I have not been out for a ride yet but It does seem easier to kick...... although I don't have anything to compare it to.      

[markparrish]

I had an 07 rev 3 270 - I fitted a couple of thick base gaskets, I think it softened the engine a bit but can't promise it made it much easier to kick. It's worth a try though and they seem fairly easy to source online.

[mcman56]

In addition to making it easier to kick, the extra 1 mm of base gasket softened the engine response a bit.  I also think it quieted the exhaust pop, pop, pop a bit.   None of the changes are night and day differences but all noticeable and worth doing if you want that type of change. I'll probably remove the flywheel weight.. 

[RonH]

Hey jbrandt,

I realize this is an old thread but I was just wondering how it went for you? I have a new Gasgas and it kicks me back like a mule. Did the head spacer work! I just ordered one myself and am hoping for the best.

Thanks!