Hesitancy

[Camulus]

Hi,
I'm currently riding a 2H9 (European model) and with the help of this and the UK site I've maneged to sort most problems.

However, the bike has a real 'hesitancy' below 3K revs - past that it's a missile - I've taken the carbs off and soaked with carb cleaner and blown through with air - and it seems to be worse!

I can only describe it as like running on full choke (I'm not though)

Any, preferably, simple ideas??

[natemoen]

Check the number of holes in the pilot jets. Should be 6 holes (not counting the hole in the end) in a 2-1-2-1 patter. If you have 8 holes or no holes you have the wrong style pilot jet.

[Camulus]

Appreciate that, was hoping for something that didn't require another carb removal - my knuckles have hardly healed from the last one!

Removal and strip down is on the list for winter, so not yet - although with the current messed up climat we've got it might be sooner rather than later!

[James England]

Did you do the tip for carb removal of undoing the top airbox bolts and lowering the airbox before carb removal? It's documented here on the forum. You'll find it gives just enough extra space to get the carbs out/in dead easy......

[TopCatGr58]

However, the bike has a real 'hesitancy' below 3K revs - past that it's a missile - I've taken the carbs off and soaked with carb cleaner and blown through with air - and it seems to be worse!

I can only describe it as like running on full choke (I'm not though)

Any, preferably, simple ideas??

Hey James/Nate,

I'm surprised that you didn't comment on the above bolded portion of his post!?

Camulus, you do NOT want to soak the carb bodies in caustic carb cleaner, that's a sure fire way of destroying your butterfly shaft seals and giving you some bad vacuum leaks!! Would suggest spritzing some carb cleaner or other combustible stuff around the shaft seals while it's running to see/hear if you notice any changes in rpms. IF so, then you've damaged your seals and you'll need to add that to your winter tear down list along with the carb cleaning. I think it's covered in the carb tech tip, but you'll need to grind off the ends of the shaft screws to be able to remove them, get some new ones that you can peen or use locktite to prevent new ones from working loose and getting sucked into the engine!

T.C.

[motoman]

Good point by TC, but doubtful those seals are damaged. Definitely lean on those two cyls. So easy to pull these carbs, would be a good choice and check the float levels on those lean two cyls. compared to the other two that are showing a good burn. When running correctly, these ARE a somewhat lean burn motor anyways. Overall, better to be a bit on the rich side, as I've already seen on here this riding season two motors with holed pistons. Don't think you really wanna be that third member to report this......just sayin.

[natemoen]

Hey James/Nate,

I'm surprised that you didn't comment on the above bolded portion of his post!?

Camulus, you do NOT want to soak the carb bodies in caustic carb cleaner, that's a sure fire way of destroying your butterfly shaft seals and giving you some bad vacuum leaks!! Would suggest spritzing some carb cleaner or other combustible stuff around the shaft seals while it's running to see/hear if you notice any changes in rpms. IF so, then you've damaged your seals and you'll need to add that to your winter tear down list along with the carb cleaning. I think it's covered in the carb tech tip, but you'll need to grind off the ends of the shaft screws to be able to remove them, get some new ones that you can peen or use locktite to prevent new ones from working loose and getting sucked into the engine!

T.C.

I don't feel that it is a sure fire way to cause leaks, that's why I didn't say anything at this point. I think people over react to soaking carbs. Can it cause problems, sure It can, but so can leaving the carbs to sit and dry out for 30....

Can the cleaner case the seal to swell, yeah some do, but it doesn't case them to fall apart. So if there are holes then they were there before. If anything soaking rubber causes the rubber to deteriorate and turn into a gummy sticky mess.

[Camulus]

Thanks for the input guys -

Yes I know the 'trick' for getting the carbs out but when you've got the hands of a cave troll it's still quite difficult!

I should have been more explanatory re the soaking, I soaked them first in paraffin (not sure but I tbink you call it kerosene) and then blew hrough with compressed air. I then sprayed carb cleaner into all the various orifices and again blew out with air, I didn't actually 'soak' them in carb cleaner.

It's strange but it had this hesitancy when I first got it, but since doing this it's got worse?

[ManagerMike]

First off keep in mind, these bikes are a bit weak in the knees until around 3000 rpm, that's when they just start breathing well. What you descibe as hesitancy, you also describe as becoming worse after having monkeyed with the carbs, so if indeed you had an issue to begin with, and have made it worse, it is most assuredly linked to what work you performed on the carbs. Possibly, you mearly had a percieved issue, and perhaps have now created one?
You stated that you soaked the carbs, if you truly submerged them for any length of time while still assembled, they likely now have whatever solvent of your choice in the vacuum chambers above the jet needle diaphrams. That would not only affect performance but will likely result in dissolved diaphrams before too long

[petejw]

hi Camulus,
next time u take the carbs off, check the 3
little off idle ports (3 on each carb) near the butterflys,
some could be partially blocked,
also as stated check ur float heights,
and when was the last time u checked ur valve clearances?
that can cause similar problems as uve described.

[Cobia]

Mike, you have a very good point there. And beyond that, Camulus doesn't mention stripping down the carbs before soaking.
Camulus,
Did you actually take the bowls, jets, valves, diaphram and needles, etc. out of the carbs before soaking them ? And then, did you shoot carb cleaner (with the straw) into every orifice and watched the fluid come out somewhere else?
If not, chances are you just did a cosmetic cleaning that made the outside look clean. Yet, inside all this soaking did was relocate the interior crud to a different location. In your case, sounds as if it went to a location with a more detrimental effect on performance.

[Camulus]

No I didn't strip them down, was hoping that a general soaking would dissolve any contaminents.
Yes cleaner was sprayed into everything, but surely having ridden about 15 miles since there should be petrol where it's supposed to be and vacuum where it's supposed to be?

[natemoen]

I have to agree with something clogging a port and the soaking just moved it someplace else.

Gunna have to tear them down....

[johnboi71]

Check your intakes!

My intakes looked OK, but when my friend pulled them off, you could see on the head where they were leaking. I got new ones. The bike sounds better, but I ain't riding till I fix my brake. Good luck!

[Camulus]

Well, bunged in a load of Redex (not sure if you have that over there) and went for a long ride to try and clear everything................10 miles later I'm limping home on 2 1/2 cylinders and desperately trying to keep the revs above 4k to stop stalling!!!!

Looks like it's carbs off and an ultrasonic clean!