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questions about Montesa Cota 315r

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Posted by: blackduc98---------------------

I'd like to get into trials, and I'm seriously looking at buying a 2000 Montesa Cota 315r. I'll be checking out the bike next weekend, so meanwhile I've searched this forum about the Monty, and found quite a lot of info, so thank you! Hopefully you won't mind a few more questions:

Where do you buy parts? It is an HRC bike, but I've been told that normal Honda dealers can't order HRC parts. Is this true?

What is the heritage of Monty's engine? Is it a derivative of the CR250, or does it come from the RS250, or is it something else entirely?

Where do you buy a shop manual? Where can I find parts diagrams?

I talked with a guy who works on all sorts of trials bikes in my area, and he claims that he's never done a top end on a Monty because he's never seen one that needed it. Is this typical?

The premix oil ratio has me baffled. Montesa's web site says 80:1 which seems rather skimpy on oil, and kinda scares me. Why is it acceptable to run with so little lubrication?

What kind of gasoline do you use? Montesa's web site says to use a 50/50 mix of 93-octane pump gas and 105-octane race gas, otherwise the engine will knock. Is this really the case?

Looking thru the Lewisport catalog I found an extended range gas tank and seat for the 4RT. Does anybody make one for the 315 too?

Thanks in advance


Posted by: trial_07---------------------

I ran 100 low-lead fuel (would hear pinging with pump fuel) in both my Sherco's 1.25 and 2.5 mixed at 1.5 %; never had any problems and had great throttle response! Montesa are known as good solid bikes, my dad has owned a couple and loved them. They just didn't evolve a whole lot with the Cota 315R over the years.


Posted by: Patman---------------------

A 2000 Monty 315R would be a great bike to get in to trials on, I might be bias though

Parts are available though "local" dealers but they typically are not on every corner. Check out www.usmontesa.com for locations of dealers. Parts are generally available and if you keep Lewis Sport on your list you should never have an issue with parts. They are great people and VERY dedicated to the sport! The Tryals Shop www.tryalsshop.com is another great resource, Mike Komer is a great guy and knows trials! Ryan Young typically has general parts and a great video at www.rypusa.com

Get a shop manual from a dealer or maybe from an auction site. They are VERY detailed and should cover anything you might ever need to do to the bike and then some!

The Monty engine is VERY well built, duh it's HRC. I do think at least ring would be a good idea on a bike that age though.

The 80:1 premix is no problem just run a VERY good quality synthetic. I both my 315 used from a high level rider who ran it and I ran it using Amsoil premix and have since sold the bike to Rich and I know he's been putting time on it as well so it doesn't seem to cause any durability issues. It's acceptable because the bikes are not run at high RPM for extended periods of time idle to off idle are the majority of time on most trials bikes.

I used VP MR2 at 100% and had no issues. Rich suggested it to me and I always have very crisp throttle response. Since they use such a small amount of fuel anyway using the good stuff is not that expensive.

There should be an extended range tank available for the 2T Monty as well, call Adrian or Mandy at Lewis Sport and ask.

Congrats!


Posted by: trial_07---------------------

I had great service with Ryan Young; and Neil Carter in Ontario. They are Sherco people though...


Posted by: wayneg---------------------

I would definitely put in some new rings - mainly just for peace of mind as you know what you're dealing with then. The parts aren't that expensive, and the Monty is a very well proven and durable bike. You seem to have very good support from the US distributor, so it will be an easy bike to own.

The oil ratios depend on how you use the bike, and the oil you use. For example I am a very unskilled Clubman level rider, and I have problems on my Beta with things oiling up a little too much using 80:1. I may need to try a lower level of oil or twist the throttle a little bit harder!!

I highly recommend the Ryan Young training video, and also for you to enter Trials events in your area. Competing in an organised event will test your skills no matter how well you ride as there is always another higher grade to try out. Organised events will also be an introduction to other Trials riders who are an unusually helpful and friendly bunch. The more information you can learn and practice the better that you will ride - also as cross training for any 'normal' dirt bikes that you have. Most of the top European Moto-X riders such as Josh Coppins and Stefan Everts have a good play around on their trials bikes.


Posted by: blackduc98---------------------

Thanks for your advice, Patman. The bike already had piston & rings replaced last year because the owner experienced a WFO stuck throttle, and the kill switch didn't do its job, so he shut off the fuel petcock and let it run out of fuel. Oh, and a small twig was jammed in the fan. Evidently this caused the thing to get quite hot, especially as it got lean towards the end, which resulted in a "mild" ceasure. Piston was replaced and cylinder was honed. BTW, here are some pics the owner sent me:

http://pictures.aol.com/ap/singleIm...Cv4xQp5Fd3Ig%3D
http://pictures.aol.com/ap/singleIm...4v4xQp5Fd3Ig%3D
http://pictures.aol.com/ap/singleIm...dv4xQp5Fd3Ig%3D
http://pictures.aol.com/ap/singleIm...nv4xQp5Fd3Ig%3D
http://pictures.aol.com/ap/singleIm...Fv4xQp5Fd3Ig%3D
http://pictures.aol.com/ap/singleIm...Iv4xQp5Fd3Ig%3D
http://pictures.aol.com/ap/singleIm...-v4xQp5Fd3Ig%3D
http://pictures.aol.com/ap/singleIm...Qv4xQp5Fd3Ig%3D


Posted by: Patman---------------------

Lokks like that might be a 2001. The 2000 had grey plastic with a carbon fiber look tank and if I recall correctly the coating on the fork legs was a bit different. Of course the plastic could have been changed out but I seem to recall the coating being darker on the 2000's and a bit more of a progressive fade on the new bikes like what I see in the pics.


Posted by: blackduc98---------------------

Folks, thanks for all the info, I'm now the proud new owner of this baby!

Patman, the previous owner insists it is a 2000 model, but I haven't found anything on the VIN plate that lists the year of production. Is there some hidden place I should look?

The first thing this bike desperately needs is new chain and sprockets. I inherited a tattered Owners Manual with a few pages missing, and so far I have been unable to find chain type spec in the manual. Is it a 420 chain? Should I bother looking in all the usual places (e.g. rockymountainmc.com) or should I just call Lewisport.com?

Before I bought the bike I checked compression and took off the header pipe and looked inside the cylinder (it had a new top end after a mild ceasure last year). Cyl & piston look OK with a fair bit of carbon on piston crown. Compression was 220 psi, but the manual doesn't list proper compression, so any info on that would be appreciated.

Are these bikes very sensitive to jetting? Also I noticed that there are Keihin carb conversions available. What is the reason for this? Is the stock Dellorto really quirky? I'm not looking for more power - I just want to get it running as crisp as can be expected.

And finally a question about fuel storage: since race gas is very stable, is it ok to leave a 50/50 pump/race mix sitting in the fuel tank and carb float bowl for a while?

Sorry about the avalanche of questions, and thanks in advance.


Posted by: trial_07---------------------

I can answer one.

I had changed the stock Delhorto carburator on my '04 Sherco 2.5 for a Keihin PWK 28mm. Only modification I had to do was change one rubber tube for a larger tube (got a truck radiator hose). Throttle response was much better, exactly what I was looking for. I can't remember the jets sizes, but I'll look it up and try posting that later.

Hope this helps!

BTW did you check all those bearings around the suspension (dog bones, upper, lower, etc)? This is very important in trials.


Posted by: blackduc98---------------------

Quote:
Originally Posted by trial_07
I can't remember the jets sizes, but I'll look it up and try posting that later.
Thanks for the info.
Quote:
BTW did you check all those bearings around the suspension (dog bones, upper, lower, etc)? This is very important in trials.
Previous owner changed all bearings in suspension linkage last year, but I'll be tearing down the bike over the winter because it needs front&rear wheel bearings, so I might as well go thru the whole bike. BTW, I'm surprised to see a complete lack of external dust seals on the wheel bearings.


Posted by: Patman---------------------

I'm just really convinced it's a 2001 becuase of the plastic & graphics, not a bad thing as they are all pretty much identical anyway.

I'm going off of memory but I believe you can put 520 chain & sprockets on the bike. I'd double check with Lewis Sport or Apex or Ryan Young and get a matched set anyway. Lewis Sport usually has the "tickest" stuff BTW.

Yes the bikes are very affected by jetting, get it dialed in and the stock carb will be perfectly fine. If you get it jetted correctly to run on something like VP MR2 and then put a white throttle assembly on it you sould be more than happy with the snap, almost to the point of being scary. If you are lucky you might turn up a roller bearing throttle that will make smooth a whole new expectation. Rich bought my 315R and I had a custom setup I got from Ray Peters that was maybe a bit too smooth and quick.

I would suggest mixing less fuel and leaving the unmixed fuel in the metal can. It's easy to mix up more and there will be a noticable difference in fresh vs. old.

I would suggest looking in to different pegs (I believe Rich installed Pivot Pegs), a handle bar that gets you positioned correctly on the bike (critical on a trils bike!), I liked the shorty levers, and maybe a spare throttle assy (black & white tubes are nice to have on hand). Get a tire guage that reads to the nearest 0.5psi, some proper trials boots & helmet (carbon fiber is my choice, heck if mine is your sixe I might make ya' a deal) and if you ride in myddy areas maybe add a few spacers under the front fender bracket to give another 1/4" of clearance. I used some black nylon bushings in keeping with the black theme on my bike (it was a 2000 ) but some stainless washers would work fine as well. Some metal bar ends will keep you from wishing you had them after you drop the bike which will happen at the worst possible time and wire the grips (2 places shoul be fine).


Posted by: blackduc98---------------------

The graphics do look like 2001, but my brakes are definitely from a 2000. The '01 has 4-piston caliper up front, along with slotted rotors, whereas '00 has a 2-piston caliper and solid rotors. The carbs are different too, and mine seems to be the '01 variety, but I'll know for sure when I take it apart. So maybe my bike is some kind of hybrid, or an early '01 prototype. My opinion is based on my examination of the online parts book, which could of course be wrong. BTW, if you don't have it bookmarked yet, here is the URL for it:
http://www.apexmotosports.com/monte...%20book/e-1.htm

Patman, let me know what size your CF helmet is, and how much you want for it. Drop me a note at blackduc98 at yahoo dot com.

BTW, is there a Monty enthusiast web site? The more technical details, the better.


Posted by: blackduc98---------------------

FWIW, after taking my carb apart I am sure it is not a 2001 but rather a 2000-vintage carb (PHBH26cs). Those Dellorto carbs sure have a lot of parts compared to a Keihin, and the air holes in the pilot jet atomizer nozzle are downright microscopic compared to those in a Keihin pilot jet. Looks like the smallest spec of dirt will clog them.


Posted by: Patman---------------------

Yup it's easy to get the carb dirty, a filter is highly useful.

I'll let ya' know on the helmet when we get back to Tx. in a few days.


Posted by: SpeedyManiac---------------------

Hi guys, I'm also looking at a Montesa Cota 315R, of the 1998 vintage. Here's the bike. http://www.gasgaspacific.com/bikes_...ails.php?a_id=1

Good deal? BTW, GasGas Pacific is a sponsor of mine so I'll probably get a deal on the price, or possibly trade my 01 EC200 for it. Opinions?


Posted by: blackduc98---------------------

That's way too much money for a '98. I'd say it is worth no more than $1800. You can get a much more modern bike for $2800 USD which is about the same $$ CDN according to today's exchange rate. I'm fairly happy with my '00 but many people say that all trials bikes improved significantly in 2003.


Posted by: SpeedyManiac---------------------

Used bikes go for significantly more money up here for some reason. I'll try and talk down the price. I'd love to go with an 03 or newer bike, but they're in the $4000+ price range up here and that's out of my budget if I want to go to the Six Days in Greece.



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