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Discussion Starter #1 (Edited)
Hi, UK newbie here.. I've bought a brand new c1 and done a few small mods to it, lick of paint and changed the rad bottle position.. and a few other little things..

I took her for a spin at the local track and I can only do 3-5 laps (small track) before she over heats? the bike starts to bogs at the low end of the RPM range and becomes less responsive, I take no chances and cut it out. I know these bikes are very temperamental and are notorious for cooling problems but is this normal???

I have bled the cooling system, including burping it using the bleed screw at the top of the hose, tilting the bike in various ways to get out any unwanted air. Would changing the rad bottle position have any effect on the cooling?

I'm looking for one of the CNC long aluminium radiators if anyone has one in the UK??

TIA
 

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Welcome aboard, I am in California, I have the 50cc ( 46cc ) C1, water cooled and 39cc air cooled Blata clone engine in a W/C C1 frame. If your in England try www. Petrolscooter .com There China made and not very good quality. Take the starter housing on the right. You will see the water pump pulley driven by an O ring belt off the back of the flywheel. Turn the flywheel by hand to see if the pump pulley turns. My pump shaft froze, burnt the belt off and then the water seal leaked the coolant in to my engine, and my brain blew a gasket, lol. Tell me what you see. If you click on the red Garage under my avatar photo you will see the C1s and Banshee Sho.
 

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Why did you mount the coolant bottle on the seat unit😳😳.
When the bike won't fire up your clutchseting is wrong. Sounds like to low engaging rpm. Should set to about 8000rpm.
Check the waterpump like the other said.
I'll have a used BZM and used Polini radiator on stock, I'm located in Austria.
 

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Thank you for all your input! It was my next step to check the water pump by cranking the flywheel. How do I remove the flywheel if I want to? I tried to on my friends c1 but it did not want to budge!!

I moved the rad bottle because I wanted to have dead straight handlebars without the bottle getting in he way. I find the default position uncomfortable as I'm 6'3. I took it a step further by redrilling the handlebars to make them a little wider. A friend had a rad bottle explode in his face so I don't fancy that either! It's also a tactic to leave some slippery coolant for the chasing contestant to deal with 😉

I'm aware I need to set my clutch as it was intermittently slipping on the track which probably didn't help the heat situation!

Any other recommendations I should check/ mod? I will get round to rebuilding the engine using decent gaskets, bearings, and viton o rings etc. But wanted at least a few laps on her first!
 

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Next question, is it a 39cc or 50cc engine, can't tell from the outside, the 46cc has a bigger cyld and piston?? The flywheel is on a tapered shaft with woodruff key to keep the magnets in the right position, There should be 2 threaded holes on the flywheel, you turn in 2 long 50mm x 5mm x 0.8 pitch bolts thru to the cases, evenly till it pops off. My C1 has SKF bearings, good seals. The pump shaft on mine has 2 small SKF bearings and a Dupont red silicone shaft seal, way better than the stock stuff.
 

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Thank you for all your input! It was my next step to check the water pump by cranking the flywheel. How do I remove the flywheel if I want to? I tried to on my friends c1 but it did not want to budge!!

I moved the rad bottle because I wanted to have dead straight handlebars without the bottle getting in he way. I find the default position uncomfortable as I'm 6'3. I took it a step further by redrilling the handlebars to make them a little wider. A friend had a rad bottle explode in his face so I don't fancy that either! It's also a tactic to leave some slippery coolant for the chasing contestant to deal with 😉

I'm aware I need to set my clutch as it was intermittently slipping on the track which probably didn't help the heat situation!

Any other recommendations I should check/ mod? I will get round to rebuilding the engine using decent gaskets, bearings, and viton o rings etc. But wanted at least a few laps on her first!
If your overheating Id check your squish , jetting and sparkplug type also your crankseals as these all control engine temps..How are you mixing the gas n oil and what type of 2 stroke mix are you using?

Doing a pressure check on the cooiling system will reveveal any waterleaks and doing a leakdown test will reveal any other types of leaks like crankseals ,crankcase seals or even the headcap/base seals aswell as the reedblock seal….Even a loose sparkplug or a bad sparkplug compression crimp seal will cause high heat problems and also burn holes right through pistons.

This device takes care of both...……..

Welcome to the world of owning a European designed pocketbike………..

https://www.amazon.com/Mityvac-MV4560-Radiator-Cooling-Pressure/dp/B003V9L05G/ref=asc_df_B003V9L05G/?tag=bingshoppinga-20&linkCode=df0&hvadid=&hvpos=&hvnetw=o&hvrand=&hvpone=&hvptwo=&hvqmt=e&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=&hvtargid=pla-4583795260972769&psc=1



Good Luck
 

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I'm not sure on the displacement.. the guy said they were 49cc but I just assumed they were 39.. the guy didn't seem to know much about these either.

Thankyou I will go away and check once I decide to strip the engine. I have read that they come with too much squish stock. As I'm still in the break-in phase, I'm mixing 25:1 with RockOil synthetic Mx oil.

I'm running a B9ES plug as I read the stock Tourch plugs melt which doesn't suprise me.. but I did get the NGK plug off Amazon for £2.55, so I'm a little suspicious as to whether it is a real NGK plug? Has anyone heard of fake NGK Plugs? Is there such thing? I mean I know the Chinese like to copy everything!

I remember seeing the threaded wholes on the flywheel, I will give that a shot, thanks! As for the tool I will be giving that a go on payday 🙂
 

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The bore of the 39cc is 37mm, the 50cc is 39.5mm, the stroke is 37cc, and your piston has 1 ring. Your head gasket is China rubber, so never try to start it without water, I ran mine for 15 seconds without and ruined it. I put Dupont florocarbon O rings in mine after so many water problems. My BZM and Polini clone have water pump and belt on the left outside.
 

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WATER PUMP BELT: The stock supplied water pump belt is found by taking off the pull starter. You will see a black belt that is around a little wheel, behind the flywheel. The stock water pump belt is not the highest of quality, and for some users has snapped. The bad thing about this is that if it snaps, it will cause the system to not function and you won't find this out until your engine is damaged . Again, this is one of the first things you should buy for the blata replica's engine.
 

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Thanks My kitty. Have you got a link for where I can buy a good quality water pump belt? Or shall I just measure it and get a good quality o ring?
 

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Thanks My kitty. Have you got a link for where I can buy a good quality water pump belt? Or shall I just measure it and get a good quality o ring?
The best way is to convert to the original Blata water pump with the toothed belt.
If you want to use the oring, measure it, you should get a new one in a workshop.
If you make a few holes in the pull starter you can check the oring from the outside.
 

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Thanks My kitty. Have you got a link for where I can buy a good quality water pump belt? Or shall I just measure it and get a good quality o ring?
The best way is to convert to the original Blata water pump with the toothed belt.
If you want to use the oring, measure it, you should get a new one in a workshop.
If you make a few holes in the pull starter you can check the oring from the outside.


I have found the OEM blata pulley and belt (see pics), but would that mean I need the Blata flywheel too? I need to just take it apart really iland have a look for myself.
 

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i think they use a O ring for a belt on most of them the o ring dry rots cracks and falls apart or the pump shaft seizes up because the the engines cooling system is built out of dissimilar metals. should never leave watter in the bike it needs to be drained after your done rideing it no one wants to drain them after they run them amd thats why there are not many around anymore
 

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I have found the OEM blata pulley and belt (see pics), but would that mean I need the Blata flywheel too? I need to just take it apart really iland have a look for myself.

In my experience with Blata engines in 8ft r/c boats is when you convert the engine to a toothed belt it adds more stress and friction than a regular o-ring

...

The waterpump belt must allow for some slippage to allow the engine to rev up quickly at times where a toothed belt will hold back the revs the engine wants to make through hydroststic friction also those stresses will eventually delaminate the belt and really gum-up the works and yes that is a 20mm pumper carb bolted onto it....Until you've done the mod will you ever know the clean crisp revs aswell as a burst of power that surpasses the ability of the floater carb hands down especially more so when you're able to easily fine-tune the engine for the current conditions without removing a carb or changing jetting......….

The way those cog belts are spliced together is their main design flaw...………

Ive worked in the microrobotics field for a short bit back in 02 and all Ill say is those toothed belts that weren't Kevlar based and meticulously spliced didn't last very long in the chip scanner machines we built that eventually put 4000 Motorola employees out of work...

Stick with the o-ring in there and just get a better quality o-ring that will last much longer and simply drill an inspection hole to monitor the belt..

That's why I like my Polini better....My waterpump is external and its also driven by an o-ring off the rear wheel....





Good Luck
 

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Lol, this item is out of stock, typical when searching for C1 parts. Neither of them Blata parts will work on your C1, that's for the newer Blata engines I believe. First the wheel is to big in diameter, the D shaft mount hole is way to big for your water pump shaft.
And there is no notched belt pulley on the back side of your flywheel which is one piece. if the pump is good. just find a good Quality bearing and seals shop. usabearingsandbelts ,com has all kinds of stuff, even Amazon has bearings. Get the numbers off the bearings and seals, so you can just type in the number and it will show you.
Oh yeah, the best part, and the reason I hate Blata engines, when your bearings or seals go you need to pull the engine and split the cases to fix it, arrrrr. The newer Blatas you can pull the pump shaft.
 
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