Author Topic: Correct jets  (Read 730 times)

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Offline BlueSmoked

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Re: Correct jets
« Reply #15 on: June 15, 2021, 09:57:30 PM »
I know the feeling and frustration! But keep, at the end you will have a nice smooth running smoke machine ;0

I think you already checked, but just to be sure, how is the air filter?

Offline Davlea

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Re: Correct jets
« Reply #16 on: June 16, 2021, 07:52:20 AM »
Air filter good thanks

Online 5port

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Re: Correct jets
« Reply #17 on: June 16, 2021, 08:17:13 AM »
Don't get fed up.  Believe me, we all have problems with our bikes! 
You haven't really described your symptoms about "too much fuel"?  Can you say more please?
Cheers

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Online c50

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Re: Correct jets
« Reply #18 on: June 16, 2021, 09:29:22 AM »
Choke checked and cleaned looked fine, float heights checked and valves are ok sealing. My patience is starting to run out with this bike. I am waiting for new Mikuni brassware so fingers crossed.

“Looked ok” ?? Did you check it seals fully off?? Also no mention of air correction being checked ?? The air jets are behind the brass blanking balls in bell mouth, you cannot get to them without removing but you can check if they are  blocked! They WILL cause rich running at higher revs if blocked along with a leaky choke.
« Last Edit: June 16, 2021, 09:33:24 AM by c50 »

Offline Davlea

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Re: Correct jets
« Reply #19 on: June 16, 2021, 08:45:46 PM »
After I cleaned out the carb it ran around the garden ok left it idling for a minute while I got my gear on to go a run on the road
and it was all dead no power before I got to the end of the road took the plugs out, wet. It was running pretty good until I put the new carb kits in. The choke is sealing ok but it will start from cold with no choke. What is the procedure check air jets behind the blanking balls are clear. Thanks

Online c50

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Re: Correct jets
« Reply #20 on: June 16, 2021, 09:09:08 PM »
After I cleaned out the carb it ran around the garden ok left it idling for a minute while I got my gear on to go a run on the road
and it was all dead no power before I got to the end of the road took the plugs out, wet. It was running pretty good until I put the new carb kits in. The choke is sealing ok but it will start from cold with no choke. What is the procedure check air jets behind the blanking balls are clear. Thanks

If it starts without choke, the choke is effectively on, they never start without choke unless within half hour of running max ! Sorry if you know but down is on and up is off? I have seen on youtube people doing it the other way around! How do you know the choke is sealing off properly? I would also check the float heights and that the float needle isn't leaking allowing it ! to flood.
« Last Edit: June 17, 2021, 08:52:11 AM by c50 »

Offline tony2stroke

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Re: Correct jets
« Reply #21 on: June 16, 2021, 09:25:22 PM »
I notice you say carb kit, I am not aware of a Mikune carb kit, just Shambits and Shyster (or Yambits and Keyster to give them their real name) you said ealier that you were waiting for new Mikuni brass bits, have you fitted new gen Mikuni brass bits, or is it on another make carb kit, as has been said on this thread, they are not correct and the bike won't run right without gen Mikuni brass bits, there are many many threads on here about people fitting after market kits and then the bike won't run correctly.

Offline Davlea

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Re: Correct jets
« Reply #22 on: June 17, 2021, 10:31:53 PM »
Hi yes as I mentioned it has a Yambits kit on it, I have not had any carb parts from them but have had many parts from them over the years and found them selling good stuff. I am still waiting for the Mikuni parts I have ordered, will give you an update when I fit them.

Offline BlueSmoked

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Re: Correct jets
« Reply #23 on: June 21, 2021, 05:57:18 PM »
Choke checked and cleaned looked fine, float heights checked and valves are ok sealing. My patience is starting to run out with this bike. I am waiting for new Mikuni brassware so fingers crossed.

“Looked ok” ?? Did you check it seals fully off?? Also no mention of air correction being checked ?? The air jets are behind the brass blanking balls in bell mouth, you cannot get to them without removing but you can check if they are  blocked! They WILL cause rich running at higher revs if blocked along with a leaky choke.

C50, is there a way to check or clean the air jets?

Offline tony2stroke

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Re: Correct jets
« Reply #24 on: June 21, 2021, 07:22:26 PM »
https://www.aircooledrdclub.com/smf/index.php?topic=53917.msg425145#msg425145

A pictured guide to get your balls out, and clean the air passage behind.

Online c50

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Re: Correct jets
« Reply #25 on: June 21, 2021, 07:28:35 PM »
Choke checked and cleaned looked fine, float heights checked and valves are ok sealing. My patience is starting to run out with this bike. I am waiting for new Mikuni brassware so fingers crossed.

“Looked ok” ?? Did you check it seals fully off?? Also no mention of air correction being checked ?? The air jets are behind the brass blanking balls in bell mouth, you cannot get to them without removing but you can check if they are  blocked! They WILL cause rich running at higher revs if blocked along with a leaky choke.

C50, is there a way to check or clean the air jets?

There are many posts on “removing your balls” !

I have said this many times too. To check if the AC is blocked: pull the two small pipes from the bottom of the carbs out of the airbox. Blow down them, you should be able to with moderate resistance, its a small jet. If you cannot blow down them the AC is blocked probably at the air jets. Even if clear there could be crud in there. I run carb cleaner down through the pipes occasionally when running at idle. If blocked you will have to drill and pop the brass balls out to get to them. And you should replace or blank of again afterwards.

Re Yambits stuff, it’s pattern and from mixed sources with equally mixed quality. Some I have just binned straight away, some I use as a last resort if oem not available. Some doesn’t fit or is wrong for your model. Especially air filters, pistons  and piston rings.

Online c50

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Re: Correct jets
« Reply #26 on: June 21, 2021, 07:29:31 PM »
Tony 2T beat me to it!

Online 5port

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Re: Correct jets
« Reply #27 on: June 21, 2021, 09:18:57 PM »
After I cleaned out the carb it ran around the garden ok left it idling for a minute while I got my gear on to go a run on the road
and it was all dead no power before I got to the end of the road took the plugs out, wet. It was running pretty good until I put the new carb kits in. The choke is sealing ok but it will start from cold with no choke. What is the procedure check air jets behind the blanking balls are clear. Thanks

If it starts easy from cold (less than 20*C engine temp, so almost always overnight UK temps!) without "choke" at all, it is probably very rich on the Idle air screw setting or the Pilot jets are too big.  You are getting gen Mikuni so, as well as making sure you get 22.5 Pilot jets, do make sure the Idle air screw adjustment is "One and a Quarter" full turns out from lightly seated.  Cheers

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Offline BlueSmoked

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Re: Correct jets
« Reply #28 on: June 22, 2021, 06:06:17 PM »
Thanks guys for reply!

Online c50

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Re: Correct jets
« Reply #29 on: June 23, 2021, 06:04:25 PM »
It shouldn’t start from cold without choke unless it’s been running within half an hour or so. The pilot circuit isn’t able to provide anywhere near enough enrichment to enable cold starting. The choke provides immensely more fuel than the pilot circuit ever could. Most good standard bikes will struggle to start after 15 mins of not running

However there is an exception which isn’t a fault you need to consider. If it’s been stop started a number of times without being ridden it is possible the fuel enriched oil build up in the crankcase will provide enough enrichment to enable it to start from cold without choke. But after a good run on the road it should need at least 10 seconds of choke to start from cold next time.