HELP RH50S 70cc overheating

czechojo · Posted: Fri Aug 10, 2018 9:15 pm Post subject: HELP RH50S 70cc overheating

Hi I recently installed a malossi 70cc cylinder and malossi/dellorto phbg 19mm carb and uni pod filter. it has 6g dr pulley sliders and is over heating … right now until new jets come in the carb has a 80 main and 45 pilot with 55 choke... needle all the way rich... prima pipe that looks identical to stock pipe...
any suggestions?
thanks

Stanza · Posted: Fri Aug 10, 2018 9:47 pm Post subject:

Park it till you get bigger jets in. You don't want to torch the rings.

czechojo · Posted: Fri Aug 10, 2018 11:09 pm Post subject:

yes that sux but probably a good idea..

czechojo · Posted: Sat Aug 11, 2018 10:32 pm Post subject:

so can overheating be caused by jets being too small?

Stanza · Posted: Mon Aug 13, 2018 1:31 pm Post subject:

Very yes. If you are running too lean for that top end, because the main jet is currently too small, you end up with a much hotter burn. It'll run great, right up until it goes "clatter clatter stop"

czechojo · Posted: Mon Aug 13, 2018 2:13 pm Post subject:

ok, I have another question. it's difficult to describe but I noticed a quick buzzing sound when I quickly let off the throttle. so I slowly left off the throttle and noticed at a certain low throttle position there is a buzzing or rattling sound. the problem is it seems to be getting worse like louder and stronger.. any idea what that might be in spite of the limited description? ty

Stanza · Posted: Mon Aug 13, 2018 6:30 pm Post subject:

Could be a few things. Can you tell where the sound is coming from? Exhaust vs top end? If it's coming from the top end, is it a partial exhaust leak? If not, you may have a ring that is seated badly, or is becoming more damaged from the overheating. Less fun is the possibility that you have a wristpin bearing that is faulty, and rattling around.

Moving away from the top end, if the sound is coming from more towards the back of the case, you may need to check your front variator, see if those roller weights are jangling around at low rpm.

czechojo · Posted: Tue Aug 14, 2018 1:31 pm Post subject:

ok so it has turned into more of a consistent jingle at any throttle position, im thinking the rollers is probably right. I have a variator and clutch coming this week so i'm trying to wait for it before opening it up. appreciate the info, I'll let you know what I find

czechojo · Posted: Fri Aug 17, 2018 7:10 pm Post subject:

still waiting on ther clutch and variator but I got the jets in and it is still running hot. well having a 70cc run hotter than the 50cc? I switched from an 80 to 100 main and 42 to 48 pilot... runs good but really hot and loses some power.. I have a large intake by ncy that I haven't installed, I want sure how that would affect things, could installing that help and would that require rejetting?

Stanza · Posted: Fri Aug 17, 2018 7:47 pm Post subject:

Just ruling out the dumb stuff......is it possible you have the piston in upside down? The arrow should point towards the exhaust port.

czechojo · Posted: Sat Aug 18, 2018 12:51 am Post subject:

arrow is pointing to exhaust.. do you think the uni filter could be letting in to much air?

Stanza · Posted: Mon Aug 20, 2018 2:15 pm Post subject:

Have you done a plug chop yet? If not, do one pronto.

czechojo · Posted: Wed Aug 22, 2018 1:23 pm Post subject:

I went to 3 different parts stores and none of them had the plug in stock so I ordered a few that will be in today at 3pm... I ended up getting the bike to run fairly decent, it runs on the warm side but didn't seem to be dangerously hot.. now I put in a malossi delta wing clutch with white springs and a malossi multivar variator with 7g weights add yellow contrast spring and now the bike is running at way higher rpms at every speed which is ther last thing I needed, now it's back to running hotter.. would changing the springs help that? if so should I change the clutch or contra or both and which colors? .. ty for all your help