Skip to content
View in the app

A better way to browse. Learn more.

Trials Central

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

4Rt Oversize Radiator Help.

Featured Replies

As usual Nigel your post is a wealth of really useful technical information :rolleyes:

 

According to many adverts a 2016 Repsol 260 is £6,999, which by the time you have picked it up or road registered it makes £7k+.

 

Whether or not I have been to Australia or not is irrelevant, for many years I was involved in the design and manufacture of equipment to work in countries such as Northern Canada, Azerbaijan, India, Indonesia etc where ambient temperatures well above (and below) 38 Celsius are common. The 260s cooling system is probably focused on typical WTC use where even high ambient temps won't cause problems. Honda should offer an optional larger radiator or oil cooler.

Edited by dadof2

  • Replies 30
  • Views 10.4k
  • Created
  • Last Reply

Top Posters In This Topic

Most Popular Posts

  • I think it's to replace the steel heat shield (baffle) that sits between the exhaust header and the electronics that sit on top of the gearbox.   Edit: (thanks to Sportsawyer) baffle replaces 11206-NN

  • crazybond700
    crazybond700

    Definitely use coolant, and have heart good stories about ''better'' working coolants which are offcoarse more expansive.   A bigger radiator doesnt solve your problem, if the bigger one gets dirty

  • nigel dabster
    nigel dabster

    Dadoff you ever been to australia (38 dgrees he said)? To expect every trials bike to be capable of every conditon worldwide is silly in the extreme. Especially for 7k (which bike ais 7k?) Oh dear in

Posted Images

2016 bikes have slightly different fan mount to avoid stones etc but think rads are same.

Sure I read somewhere that the original 280 sainz map ran rich to aid cooling -or something similar

For Scott/SSDT prevention much better than cure - remember Tarres on first Zero -probably many months and much money on developing the water cooled engine then stopped for the sake of a mud flap and some mesh.

 

JR  - as a side  - fuel pump problems start a bit like the stutter when hot and then fine after standing. Might be time for filter clean in the tank as precaution

 

Dai - spend your money down the Gym -bike wont get so hot pulling a few kgs less around the 80miles HaHa :hyper:

 

Good point Jimmyl, its not been done for 3 years. I'll get it done this weekend (as well as fixing the front tube) and see what I find inside.

The picture is from my Toyota 4 Runner dash.  This is pretty typical temps here (Scottsdale AZ) in summer.

 

Installing a bigger rad alone does not help as the engine oil temp is a bigger problem affecting shifting, transmission, clutch etc.

 

An oil cooler is required for 4T engine longevity in really warm/hot weather.

post-260-0-01472900-1448402952_thumb.jpg

Edited by billyt

  • Author

Thanks for the replies. I'll try different coolant for a start.

Mark G

  • 1 month later...

Definitely use coolant, and have heart good stories about ''better'' working coolants which are offcoarse more expansive.

 

A bigger radiator doesnt solve your problem, if the bigger one gets dirty it also does not cool enough anymore.

 

The guys in the first three post seem to have problems in dry hot weather, so a bigger radiator would surely help.

 

And if you put a mudflap on your front fender (which is the first thing I do when I buy another bike), the radiator doesn't get clogged up so much.

 

About the bad running of the 4RT in hot conditions: This could be caused by the fuel "vapourising" in the fuel tank, which would effect the fuel flow.

Because the fuel tank is right above the cylinder head, it can get pretty hot there, especially when your radiator is clogged up and your doing high speed on the connecting road sections of the SSDT for instance.

I even read on this forum somewhere, that they saw their fuel "boil" when they did a refuel on the SSDT. 

 

Although an oil radiator (like on some of the old honda twin shocks) would help, a larger radiator for bigger engines and or adverse conditions must be a good thing, every (semi) factory rider and other top riders has one. It helps to keep the overall engine temperature lower.

Guys your right, my emphasise was on the ''if its dirty'' part.

 

Boiling fuel is/was quite a big problem in the dakar, so that could also explain it. But I would say you have more problems on idle speeds than on highspeeds, on high speeds you will loose a lot of heat just by the airflow. On slow speed the head will warm the tank.

Dadoff you ever been to australia (38 dgrees he said)? To expect every trials bike to be capable of every conditon worldwide is silly in the extreme. Especially for 7k (which bike ais 7k?)

Oh dear indeed.

 

Given that Montesa punt out the same bike worldwide (as far as I can tell) they obviously expect it to cope, are they just being silly or extremely silly?

Edited by 2stroke4stroke

DDM make a spacer and impeller for the water pump. http://www.vitititaniowtc.com/en/motorcycle-accessories-parts/light-part-ddm-prodotti-per-moto-trial.html

(Anyone know what the engine baffle is on that page?). 

 

I think it's to replace the steel heat shield (baffle) that sits between the exhaust header and the electronics that sit on top of the gearbox.
 
Edit: (thanks to Sportsawyer) baffle replaces 11206-NN4-000 "PLATE, CAM CHAIN GUIDE". See parts manual Block Number E-11, Reference Number 5.
 
 
I mailed DDM for info about it, but I'm afraid my point got lost in translation.  
These were the answers I got:

 

Q: Dear madam, sir

 

    As a Montesa 4RT owner, I wondered what the "Carbon Fiber Engine Baffle for Montesa Cota 4RT" is.

 

A: Good Day

 

  This product price is 40 Euro + Delivery cost approximately 15 Euro in Belgium.

 

 

 

Q:Hi

 

     I'm sorry but I just wanted to know where  this "baffle" can be used on my 4RT. What is the purpose of it?

 

A: The weight is 50% of original

 

 

:facepalm:

Edited by guys

DDM make a spacer and impeller for the water pump. ... (Anyone know what the engine baffle is on that page?). 

 

I think the engine baffle replaces 11206-NN4-000 "PLATE, CAM CHAIN GUIDE". See parts manual Block Number E-11, Reference Number 5.

I think the engine baffle replaces 11206-NN4-000 "PLATE, CAM CHAIN GUIDE". See parts manual Block Number E-11, Reference Number 5.

Yep, that's it!  :thumbup:

 

I think it's to replace the steel heat shield (baffle) that sits between the exhaust header and the electronics that sit on top of the gearbox.
 
Edit: (thanks to Sportsawyer) baffle replaces 11206-NN4-000 "PLATE, CAM CHAIN GUIDE". See parts manual Block Number E-11, Reference Number 5.
 
 
I mailed DDM for info about it, but I'm afraid my point got lost in translation.  
These were the answers I got:

 

Q: Dear madam, sir

 

    As a Montesa 4RT owner, I wondered what the "Carbon Fiber Engine Baffle for Montesa Cota 4RT" is.

 

A: Good Day

 

  This product price is 40 Euro + Delivery cost approximately 15 Euro in Belgium.

 

 

 

Q:Hi

 

     I'm sorry but I just wanted to know where  this "baffle" can be used on my 4RT. What is the purpose of it?

 

A: The weight is 50% of original

 

Welcome to my world Guy!! 

 

Edited by marky boy

  • 4 weeks later...

Bought the DDM impeller. Seems to work well but haven't had any 40+ days since installing.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.