Noisy Petrol CVRT Sultan

[TheAmericanPatriot]

Hello again.

I finally got one of my petrol Sultans running recently and it runs very well except there is some awful noise coming from the gearbox/engine compartment. It sounds similiar to  how it does if you try to put a cvrt  from forward to reverse or vice versa when you didnt catch it quick enough and it makes that grinding noise. Except much louder. It happens usually right when i start it up and will remain noisy until i rev up the engine to higher RPMS. At that point it goes away and 90% of the time does not return when i let the RPMS come down. It also doesnt do it every start up. Probably occurs on 50% of start ups. It has never occured at high RPMS. The sound also is the exact same everytime. Doesnt sound different no matter the RPMS.

I assumed the usual Clutch/fan bearings had gone bad and tore her all down and to my surprise everything is in extremely good condition. Clutch bearings look and feel brand new and i havent visibly looked at the fan bearings yet but it spins like a top and is very smooth aswell. I do not know where to go from here. As far as i'm concerned all thats left is the gearbox But i couldnt get the gearbox to replicate the sound when i had the fan and clutch disconnected from it. 

Any of you guys have any ideas what could be going on or experienced this before?

 

Wyatt

[sirhc]

Does the noise go away if you select 5th gear when it’s idling? 

[terryb]

idle clatter that dissappears when revs are increased is normally due to an uneven idle, and can be reduced/eliminated by balancing the 2 idle mixture screws.

once warmed up, make sure the choke is fully off, and set the idle speed as low as sustainable. doing one at a time, turn each mixture screw to achieve the smoothest idle (if idle speed increses drop it back down). once you have achieved a smooth idle at low rpm, increase idle speed to 650

it takes a keen ear, but with a bit of fine fettling works wonders!

good luck

Terry

[TheAmericanPatriot]

2 hours ago, sirhc said:

Does the noise go away if you select 5th gear when it’s idling? 

Hi Sirc, i only had it in first gear when i was shuffling it around and in first it was still making the grinding noise. I've unfortunately got everything torn apart now so i am unable to check if it goes away in fifth 

[TheAmericanPatriot]

1 hour ago, terryb said:

idle clatter that dissappears when revs are increased is normally due to an uneven idle, and can be reduced/eliminated by balancing the 2 idle mixture screws.

once warmed up, make sure the choke is fully off, and set the idle speed as low as sustainable. doing one at a time, turn each mixture screw to achieve the smoothest idle (if idle speed increses drop it back down). once you have achieved a smooth idle at low rpm, increase idle speed to 650

it takes a keen ear, but with a bit of fine fettling works wonders!

good luck

Terry

 This is a possability as i had most of my problems with getting it started dealing with the carburettor. though i had followed the tuning procedure for it after i had gotten it running but didnt spend alot of time on it. Do you really think that the carb not being tuned right can make such an awful noise somewhere? It really does sound bad, not like anything is immediately breaking and ruining stuff but it is a very clear and very loud gear grinding ish noise. It would be amazing to me if the carb not being set right causes this sound, especially since it doesnt sound like its coming from the engine either ( which it very well might be, it just doesnt sound like it)