VARADERO 125 V5 2005 HELP!!!

[ianbulgariama...]

Hi i recently bought a 2005 varadero 125, riding it home it felt like the choke was stuck and bike was lacking power and trying to stall at junctions, once i got it home we stripped it down to get access to the carbs etc, giving them a quick inspection, fixed the sticking choke and reassembled and after a bit of tweaking we got it to idle nicely then it was put away due to weather for a week or two, once i got the bike out again it started and idled no problem so i took it for a spin, i got aboiut a mile and it lost all power and cut out, figured i might be low on fuel, got it runniing and went back for fuel, again 1 mile it cut out and same situation so took it home and parked it up.

did some research and decided to strip the carbs and clean and check the jetting of it, i took lots of photos to help me identify what went where etc i also removed the thermostat which had rusted solid, soaked it in vinegar for 24hrs and tested and it now functions but no thermometer to check the temperature of it opening but drained all water out which was rusty and flushed it through and added antifreeze, i also added an inline fuel filter incase of muck in tank

carb stripped, cleaned, jets as they say in the manual, but the head of the idle screw in the front cylinder the head of the screw or the 4 wedges of the head have snapped off so i couldnt do much so left it figured not worth making it worse, adjusted rear cylinder idle screw , put it all back together and then started piping it back up
this is where i'm unsure as to the following as the manual and my pictures are unclear as to what goes where

i have a pipe that comes off the back of the water pump that i thought went to the front carb (which until today i swapped them over)but seems too long and a bad design if it does or it goes to the bottom of the thermostat housing lowest connector which it does seem right for length etc

i have a short length of pipe coming from the rear carb heater which i had running to the bottom of the thermostat housing lowest connector but hae now swapped it to the front carb as described above extended it with some clear tube to see whats happening but only drips of water present in tube

in both configurations the bike runs but not perfect but better than before i have scoured the internet to find out what goes where on the carb side and cooling side but nothing is clear enough for me to have confidence that its working and not going to overheat etc

how can i test the water pump, is it a case of taking the hose to the front cylinder and crank it over, surely if the pumps working ok it should squirt coolant out??? could the rust be blocking somewhere else before the thermostat etc, the temperature guage works on startup but defaults at cold even after an hours ride, will try and test the temp switch and or replace it next

if anyone has pictures of carb piping and locations and or water hose locations much appreciated, i cant wait to get this safely back on the road, any tips and advice greatly appreciated

[cb1rocket]

try with tank cap off partly. Sounds like a vacuum being created with a blocked breather line
____________________
Honda H100S2 Rebuild - https://www.bikechatforums.com/viewtopic.php?t=253852

[Meatybeaty]

Do you have this manual, it shows in Section 5 and 6 where the pipes go, for the heaters and carbs
https://www.manualslib.com/download/1002847/Honda-Xl-125-V1.html

[ianbulgariama...]

Thanks for the manual, it looks exactly what i need, i only had the haynes manual, this looks much better, and i will try with the cap off too, i've also been told to back flush the water system so weather pending i will try it tomorrow and keep you posted of any progress, thanks for a speedy reply, i'm no mechanic but i do work logically most of the time lol, thanks again

[Robby]

If the cooling system was that nasty, it needs a bit of attention.

First off, flush the engine and the radiator through with a hosepipe. Do it in both directions, for at least 5 minutes each way. This will loosen stuff up.

Then reassemble everything, fill it up with tap water. Leave the rad cap off, start the engine, let it warm up. You should see the water level drop when the thermostat opens, so add some more water then. Let it run for a minute more, then turn off.
Let it cool down, rad cap on, top up expansion bottle and take it for a ride.

Then drain the water into a container and see what it looks like. If it looks fairly clean, replace with proper coolant. If it still looks a bit manky, fill up with plain water and repeat the procedure.

Running an engine with just water for coolant is a bad idea for extended time periods. Water freezes too soon, and doesn't contain corrosion inhibitors. Running on plain water to clean out the system and diagnose problems is fine.

Do not put anything else in there - no magic radiator cleaner additives, no soap, no acid. If something is properly blocked, the only way to really clean it is strip down until you get to it and poke something through the hole.

[ianbulgariama...]

Thanks robby, i'm hoping to do that today so will keep you posted, thanks for your input, greatly appreciated, when i first got the bike i drained the coolant from the drain hole and it was rusty, so i kept filling the rad with clean water then draining repeatedly until it ran clear, i then removed the thermostat and cleaned all the rust and refitted, the only thing i dont know is if it is actually flowing through fully yet, but if it stays dry i will be having another go today, cheers

[ianbulgariama...]

Ok sorry for the delay but i'm limited to what i can do based on the weather until i build my new workshop, okay so here's the update and current issues lol

- Went to flush the coolant system but the outside tap broke, so resorted to getting the compressor out and try to use air to blow the system, after a few squirts of air in both the inlet and outlet pipe lots of rust and muck came out but my compressor went up in smoke, so that was the end of coolant flushing part 1

- removed all water pipes to ensure that none were blocked and replaced, on refilling the radiator the water pipe from the front cylinder going into the rear cylinder (below thermostat housing)(larger bore pipe) and the small bore pipe seem to be leaking water, ive replaced the pipes, jubilee clips etc on both but same results, is it possible that it can come from the fixed pipe within the thermostat housing / cylinder connection, maybe ive disturbed an o ring inside, (hard to tell exactly where its coming from) and not from the hoses, this is with the bike not running, just with its own gravity feed with radiator cap off

- i found out that the bike has reed valves and read about the issues they can cause, on inspection they were both crapped up with carbon, stripped and cleaned and refitted (but they didnt look the same valves as shown in the workshop manual, similar but not identical), yet to see if that makes a difference once bike is waterleak free

it seems for every step forward there's another step back lol, i'm not giving up as i must be getting closer to a good running bike lol, its just sapping all my spare time at the moment but at least i'm learning every nook and cranny of my baby varadero, again all input is greatly appreciated.
-