Glad the oil seems to make the box better, will be interesting to see how it goes long term.
That's great about the show, we're starting to see similar things at car shows here, where folks are bringing out their restoration/repair projects from their sheds/shops where they've been hidden away from the general public.
I still have to paint the tank on mine to finish it off.
He did say that he talked to another Montesa owner and he said to add an extra 25cc-50cc of oil to make it shift smoother he did say that helped also.
Bike was a big hit lots of people stopped to look at it and ask questions, two of our club members that are bike enthusiasts took it for a ride in the parking lot and loved so much asking if I ever sell it to let them know.
Hope you finish yours and get it to a show
Back in the day Montesa boxes could be problematic - too many shims, where Bultaco did a good box that only had one shim.
Might be worth a strip and check if you're fussed.
Hoping the oil change makes the difference, bike was completely rebuilt never really ran and stored until I bought it, all done by an excellent mechanic
My 74 is better than it use to be with the Maxima. I was using regular 90wt gear oil and had allot of problems with it jumping out of the higher gears while riding between sections and a few false neutrals in the lower gears. I switched to atf in both boxes a couple years ago and it worked better in my application. I just like the idea of having a heavier oil in the gear box however and the Maxima seems to be fine and I didn't notice any gear jumping. TO put this in perspective this bike has lots of hours on it so I am sure it has allot of wear on the drive train. I am kind of in the preservation mode with it but still competing with it at vintage trial events and doing quite a bit of practice on it. This bike never has shifted as well or as positively as most other bikes, and you kind of have to get use to putting up with it's little quirks, but it is a great vintage trials bike and I always get lots of compliments at events.
Definitely going to switch to this oil as I am also having the issue of it jumping out of higher gears, thank you so much for taking the time to post this
I looked at their data sheets and they say it has a zinc additive, which would normally put it in GL-4 class (although it doesn't say so) - I noticed their 80/90 hypoid gear oil says GL-5 in their advertising.
I just switched over to Maxima MTL 80w gear oil in my 74 Cota gear box and use atf in the clutch/primary. The label on the Maxima doesn't say anything specific as far as classification but I trust it to work well. I just did a trial with it and it worked well. It also says it is compatible with wet clutches so I may just go with the Maxima instead of atf in the clutch/primary....
Sam
On 4/14/2018 at 10:50 AM, sdm said:
Cant find anywhere where it says it is Classification GL-4 ?
Nice looking bike. You could drain the gearbox and try some 75w gear oil - needs to be a GL4 type oil as there's brass bits in there and GL5 will affect the brass over time.
The mechanic said he was going to use something with GL-4 per your advise because of brass, on the first page it was suggested to use Castrol Manual Vmx 80w due to the same symptoms I may go this route although it is 80w
A manual transmission fluid of advanced design especially developed to provide easier gear changes over a wide temperature range.
It is particularly versatile in cold weather as it reduces shift effort at start-up, as well as controlling transmission noise and idle rattle at operating temperatures.
Application
It should be used in manual transmissions of most car and light commercial vehicles (LCV’s) requiring GL-4 performance, where improved low temperature shift performance is required.
Features & Benefits
Quieter transmission operation and easier low temperature gear shifting improves driving experience
Improved gear tooth and bearing durability reduces the risk of breakdown and extended component life
Effective lubrication over a wide temperature range
It can be used as a low drag gearbox oil in 2-stroke motorcycles with separate gearboxes
Specifications
SAE 80W viscosity – SAE 75W-80 extrapolated (equivalent to 10W-30)
Take it easy in terms of long downhill runs for a few hours...but apart from that standard trials type riding is pretty ideal for engine break in ...but avoid labouring the engine ie: pulling away in a gear that is too high.
I would also suggest that you get an after-market compression release - as the starter gear is very vulnerable and difficult to obtain. I run 25:1 and castrol VMX80 in the gear box. Some guys recommend ATF but my 76 model jumps out of gear in every gear and false neutrals everywhere. With VMX it only jumps out for first, occasionally 2nd but no false neutrals. I am guessing that yours is around a 75 model - engine number should tell you.
So riding it around last night it is doing exactly what you are saying it is false nuetraling between most of the gears I'll need to find out what he put in the gearbox and maybe change it
There are three tank/seat options ( maybe more ). I have the standard trials body as per your photo - the 247T (trail) body with larger tank and longer padded seat and the later model large tank with very comfy seat. The latter requires rubber grommet spacers for he rear mounts but otherwise fits perfectly and is very comfortable.
This is very exciting in deed!
Looks like your bike body extends over the rear fender where mine ends before the grab bar?
What year and model is that seat from? That would be awesome for exploring
When I was exploring, I added a rear carrier from some other bike, allowed me to carry fuel, water and a few basic spares as area was quite remote - also added some blanket material to the tank so the dog would have something to grip and tied a (very) basic swag to the handlebars. I carried a bigger drive sprocket and chain extension for longer on-road travel - I could cruise about 100kph on dirt/gravel roads with the higher gearing. Mechanically the bike was standard. Attached picture taken late '74 on Cape York (Australia) - TY250b on left with scratch built longer seat over the original and the carrier and ex-army saddle-bags with mate's 175 Honda. My swag was the piece of canvas in the foreground used when repairing punctures.
There are a lot of people out there who use trials bikes for other purposes and the set-up that suits those purposes will either be to accept how the bike is, or "adjust" the bike to suit, so the set-up will depend on how it rides and what you want to do with it.
Many years ago I used a TY250b for exploring remote areas and with a couple small additions, it was perfect for the task. I also rode a couple trials on the same bike.
Kinda what I am looking to do, setup some easy sections behind my house, do some exploring and maybe do a vintage trials, my last bike the Sherco I used for exploring, one event, and riding single track
What additions would you suggest?
On the Sherco I put bar risers for a more upright standing position, and higher gearing
Interesting question, where someone expresses an opinion that may or may not be correct. Did you get the shocks set for your weight? Are they the correct length? What oil is in the forks? Have you ridden it yet?
No shocks were straight out of the box and they were the correct length listed
No idea what oil is in the forks, and yea I have yet to ride it and see how it feels, and the mechanic is a endure rider, hope to pick up the bike this week and take it for a ride to form my own opinion
Normally you can't apply a new sealer over an old sealer and it can be a big job removing the old stuff. Wait until you can see what is there as long as the original sealing job was done correctly it should be fine.
Nice bike indeed, and all the more so for still having the original tail silencer as opposed to one of those horrible sounding alloy jobs that they usually have by now.
Thank You this will be the oldest Trials bike I have ever owned, it appears to be in great shape and the friend I am buying it from really took care of his bikes, this one was never even rode after the rebuild just stored away
Depends on the brand of sealer used as to weather you can see it in the tank. Some have a white or silver look and some are clear. I used Caswell epoxy sealer in my 74 247 and it is clear so it is hard to tell. The biggest thing on having success using a sealer is good preparation. Nice bike!
Thanks I cant wait to pick it up, I think I'll just have it resealed to be safe
Montesa Cota 247 Break In Period
in Montesa
Posted
He did say that he talked to another Montesa owner and he said to add an extra 25cc-50cc of oil to make it shift smoother he did say that helped also.
Bike was a big hit lots of people stopped to look at it and ask questions, two of our club members that are bike enthusiasts took it for a ride in the parking lot and loved so much asking if I ever sell it to let them know.
Hope you finish yours and get it to a show